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Chapter 1. Installing on bare metal

1.1. Installing a cluster on bare metal

In OpenShift Container Platform version 4.5, you can install a cluster on bare metal infrastructure that you provision.

Important

While you might be able to follow this procedure to deploy a cluster on virtualized or cloud environments, you must be aware of additional considerations for non-bare metal platforms. Review the information in the guidelines for deploying OpenShift Container Platform on non-tested platforms before you attempt to install an OpenShift Container Platform cluster in such an environment.

1.1.1. Prerequisites

Review details about the OpenShift Container Platform installation and update processes.
If you use a firewall, you must configure it to allow the sites that your cluster requires access to.
Note
Be sure to also review this site list if you are configuring a proxy.

1.1.2. Internet and Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.5, you require access to the Internet to install your cluster. The Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, also requires Internet access. If your cluster is connected to the Internet, Telemetry runs automatically, and your cluster is registered to the Red Hat OpenShift Cluster Manager (OCM).

Once you confirm that your Red Hat OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually using OCM, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.

You must have Internet access to:

Access the Red Hat OpenShift Cluster Manager page to download the installation program and perform subscription management. If the cluster has Internet access and you do not disable Telemetry, that service automatically entitles your cluster.
Access Quay.io to obtain the packages that are required to install your cluster.
Obtain the packages that are required to perform cluster updates.

Important

If your cluster cannot have direct Internet access, you can perform a restricted network installation on some types of infrastructure that you provision. During that process, you download the content that is required and use it to populate a mirror registry with the packages that you need to install a cluster and generate the installation program. With some installation types, the environment that you install your cluster in will not require Internet access. Before you update the cluster, you update the content of the mirror registry.

1.1.3. Machine requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

1.1.3.1. Required machines

The smallest OpenShift Container Platform clusters require the following hosts:

One temporary bootstrap machine
Three control plane, or master, machines
At least two compute machines, which are also known as worker machines. If you are running a three-node cluster, running zero compute machines is supported. Running one compute machine is not supported.

Note

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Important

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.

Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

1.1.3.2. Network connectivity requirements

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config files from the Machine Config Server. During the initial boot, the machines require either a DHCP server or that static IP addresses be set in order to establish a network connection to download their Ignition config files. Additionally, each OpenShift Container Platform node in the cluster must have access to a Network Time Protocol (NTP) server. If a DHCP server provides NTP servers information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

1.1.3.3. Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

Machine	Operating System	vCPU ^[1]	Virtual RAM	Storage
Bootstrap	RHCOS	4	16 GB	120 GB
Control plane	RHCOS	4	16 GB	120 GB
Compute	RHCOS or RHEL 7.8 - 7.9	2	8 GB	120 GB

1 vCPU is equivalent to 1 physical core when simultaneous multithreading (SMT), or hyperthreading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.

1.1.3.4. Certificate signing requests management

Because your cluster has limited access to automatic machine management when you use infrastructure that you provision, you must provide a mechanism for approving cluster certificate signing requests (CSRs) after installation. The kube-controller-manager only approves the kubelet client CSRs. The machine-approver cannot guarantee the validity of a serving certificate that is requested by using kubelet credentials because it cannot confirm that the correct machine issued the request. You must determine and implement a method of verifying the validity of the kubelet serving certificate requests and approving them.

1.1.4. Creating the user-provisioned infrastructure

Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Review the OpenShift Container Platform 4.x Tested Integrations page before you create the supporting infrastructure for your cluster.

Procedure

Configure DHCP or set static IP addresses on each node.
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

1.1.4.1. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

During the initial boot, the machines require either a DHCP server or that static IP addresses be set on each host in the cluster in order to establish a network connection, which allows them to download their Ignition config files.

It is recommended to use the DHCP server to manage the machines for the cluster long-term. Ensure that the DHCP server is configured to provide persistent IP addresses and host names to the cluster machines.

The Kubernetes API server, which runs on each master node after a successful cluster installation, must be able to resolve the node names of the cluster machines. If the API servers and worker nodes are in different zones, you can configure a default DNS search zone to allow the API server to resolve the node names. Another supported approach is to always refer to hosts by their fully-qualified domain names in both the node objects and all DNS requests.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 1.1. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`1936`	Metrics
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101` and the Cluster Version Operator on port `9099`.
	`10250`-`10259`	The default ports that Kubernetes reserves
	`10256`	openshift-sdn
UDP	`4789`	VXLAN and Geneve
	`6081`	VXLAN and Geneve
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101`.
TCP/UDP	`30000`-`32767`	Kubernetes node port

Table 1.2. All machines to control plane
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 1.3. Control plane machines to control plane machines
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

Important

OpenShift Container Platform requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Load balancers

Before you install OpenShift Container Platform, you must provision two load balancers that meet the following requirements:

API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
A stateless load balancing algorithm. The options vary based on the load balancer implementation.

Note

Session persistence is not required for the API load balancer to function properly.

Configure the following ports on both the front and back of the load balancers:

Table 1.4. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`6443`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the `/readyz` endpoint for the API server health check probe.	X	X	Kubernetes API server
`22623`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.	X		Machine config server

Note

The load balancer must be configured to take a maximum of 30 seconds from the time the API server turns off the /readyz endpoint to the removal of the API server instance from the pool. Within the time frame after /readyz returns an error or becomes healthy, the endpoint must have been removed or added. Probing every 5 or 10 seconds, with two successful requests to become healthy and three to become unhealthy, are well-tested values.

Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.
A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.

Configure the following ports on both the front and back of the load balancers:

Table 1.5. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`443`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTPS traffic
`80`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTP traffic

Tip

If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

Note

A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes.

NTP configuration

OpenShift Container Platform clusters are configured to use a public Network Time Protocol (NTP) server by default. If you want to use a local enterprise NTP server, or if your cluster is being deployed in a disconnected network, you can configure the cluster to use a specific time server. For more information, see the documentation for Configuring chrony time service.

If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

Configuring chrony time service

1.1.4.2. User-provisioned DNS requirements

DNS is used for name resolution and reverse name resolution. DNS A/AAAA or CNAME records are used for name resolution and PTR records are used for reverse name resolution. The reverse records are important because Red Hat Enterprise Linux CoreOS (RHCOS) uses the reverse records to set the host name for all the nodes. Additionally, the reverse records are used to generate the certificate signing requests (CSR) that OpenShift Container Platform needs to operate.

The following DNS records are required for an OpenShift Container Platform cluster that uses user-provisioned infrastructure. In each record, <cluster_name> is the cluster name and <base_domain> is the cluster base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..

Table 1.6. Required DNS records
Component	Record	Description
Kubernetes API	`api.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Kubernetes API	`api-int.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster. Important The API server must be able to resolve the worker nodes by the host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.
Routes	`*.apps.<cluster_name>.<base_domain>.`	Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Bootstrap	`bootstrap.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.
Master hosts	`<master><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the master nodes. These records must be resolvable by the nodes within the cluster.
Worker hosts	`<worker><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Tip

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

The following example of a BIND zone file shows sample A records for name resolution. The purpose of the example is to show the records that are needed. The example is not meant to provide advice for choosing one name resolution service over another.

Example 1.1. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Example 1.2. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.example.com.
5	IN	PTR	api-int.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

1.1.5. Generating an SSH private key and adding it to the agent

If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent and the installation program. You can use this key to access the bootstrap machine in a public cluster to troubleshoot installation issues.

Note

In a production environment, you require disaster recovery and debugging.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

Note

You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs.

Procedure

If you do not have an SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:
```
$ ssh-keygen -t ed25519 -N '' \
    -f <path>/<file_name> 1
```
1
Specify the path and file name, such as ~/.ssh/id_rsa, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
Running this command generates an SSH key that does not require a password in the location that you specified.
Note
If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"
```
Example output
```
Agent pid 31874
```

If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> 1
```
Example output
```
Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
```
1
Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

When you install OpenShift Container Platform, provide the SSH public key to the installation program. If you install a cluster on infrastructure that you provision, you must provide this key to your cluster’s machines.

1.1.6. Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on a local computer.

Prerequisites

You must install the cluster from a computer that uses Linux or macOS.
You need 500 MB of local disk space to download the installation program.

Procedure

Access the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
Navigate to the page for your installation type, download the installation program for your operating system, and place the file in the directory where you will store the installation configuration files.
Important
The installation program creates several files on the computer that you use to install your cluster. You must keep both the installation program and the files that the installation program creates after you finish installing the cluster.
Important
Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. You must complete the OpenShift Container Platform uninstallation procedures outlined for your specific cloud provider to remove your cluster entirely.
Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:
```
$ tar xvf <installation_program>.tar.gz
```
From the Pull Secret page on the Red Hat OpenShift Cluster Manager site, download your installation pull secret as a .txt file. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.

1.1.7. Installing the CLI by downloading the binary

You can install the OpenShift CLI (oc) in order to interact with OpenShift Container Platform from a command-line interface. You can install oc on Linux, Windows, or macOS.

Important

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.5. Download and install the new version of oc.

1.1.7.1. Installing the CLI on Linux

You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command line interface section, select Linux from the drop-down menu and click Download command-line tools.
Unpack the archive:
```
$ tar xvzf <file>
```
Place the oc binary in a directory that is on your PATH.
To check your PATH, execute the following command:
```
$ echo $PATH
```

After you install the CLI, it is available using the oc command:

$ oc <command>

1.1.7.2. Installing the CLI on Windows

You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command line interface section, select Windows from the drop-down menu and click Download command-line tools.
Unzip the archive with a ZIP program.
Move the oc binary to a directory that is on your PATH.
To check your PATH, open the command prompt and execute the following command:
```
C:\> path
```

After you install the CLI, it is available using the oc command:

C:\> oc <command>

1.1.7.3. Installing the CLI on macOS

You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command line interface section, select MacOS from the drop-down menu and click Download command-line tools.
Unpack and unzip the archive.
Move the oc binary to a directory on your PATH.
To check your PATH, open a terminal and execute the following command:
```
$ echo $PATH
```

After you install the CLI, it is available using the oc command:

$ oc <command>

1.1.8. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

Obtain the OpenShift Container Platform installation program and the access token for your cluster.

Procedure

Create an installation directory to store your required installation assets in:
```
$ mkdir <installation_directory>
```
Important
You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.
Customize the following install-config.yaml file template and save it in the <installation_directory>.
Note
You must name this configuration file install-config.yaml.
Back up the install-config.yaml file so that you can use it to install multiple clusters.
Important
The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

1.1.8.1. Installation configuration parameters

Before you deploy an OpenShift Container Platform cluster, you provide parameter values to describe your account on the cloud platform that hosts your cluster and optionally customize your cluster’s platform. When you create the install-config.yaml installation configuration file, you provide values for the required parameters through the command line. If you customize your cluster, you can modify the install-config.yaml file to provide more details about the platform.

Note

After installation, you cannot modify these parameters in the install-config.yaml file.

Important

The openshift-install command does not validate field names for parameters. If an incorrect name is specified, the related file or object is not created, and no error is reported. Ensure that the field names for any parameters that are specified are correct.

1.1.8.1.1. Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 1.7. Required parameters
Parameter	Description	Values
`apiVersion`	The API version for the `install-config.yaml` content. The current version is `v1`. The installer may also support older API versions.	String
`baseDomain`	The base domain of your cloud provider. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the `baseDomain` and `metadata.name` parameter values that uses the `<metadata.name>.<baseDomain>` format.	A fully-qualified domain or subdomain name, such as `example.com`.
`metadata`	Kubernetes resource `ObjectMeta`, from which only the `name` parameter is consumed.	Object
`metadata.name`	The name of the cluster. DNS records for the cluster are all subdomains of `{{.metadata.name}}.{{.baseDomain}}`.	String of lowercase letters, hyphens (`-`), and periods (`.`), such as `dev`.
`platform`	The configuration for the specific platform upon which to perform the installation: `aws`, `baremetal`, `azure`, `openstack`, `ovirt`, `vsphere`. For additional information about `platform.<platform>` parameters, consult the following table for your specific platform.	Object
`pullSecret`	Get a pull secret from https://cloud.redhat.com/openshift/install/pull-secret to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io.	{ "auths":{ "cloud.openshift.com":{ "auth":"b3Blb=", "email":"you@example.com" }, "quay.io":{ "auth":"b3Blb=", "email":"you@example.com" } } }

1.1.8.1.2. Network configuration parameters

You can customize your installation configuration based on the requirements of your existing network infrastructure. For example, you can expand the IP address block for the cluster network or provide different IP address blocks than the defaults.

Only IPv4 addresses are supported.

Table 1.8. Network parameters
Parameter	Description	Values
`networking`	The configuration for the cluster network.	Object Note You cannot modify parameters specified by the `networking` object after installation.
`networking.networkType`	The cluster network provider Container Network Interface (CNI) plug-in to install.	Either `OpenShiftSDN` or `OVNKubernetes`. The default value is `OpenShiftSDN`.
`networking.clusterNetwork`	The IP address blocks for pods. The default value is `10.128.0.0/14` with a host prefix of `/23`. If you specify multiple IP address blocks, the blocks must not overlap.	An array of objects. For example: networking: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23
`networking.clusterNetwork.cidr`	Required if you use `networking.clusterNetwork`. An IP address block. An IPv4 network.	An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between `0` and `32`.
`networking.clusterNetwork.hostPrefix`	The subnet prefix length to assign to each individual node. For example, if `hostPrefix` is set to `23` then each node is assigned a `/23` subnet out of the given `cidr`. A `hostPrefix` value of `23` provides 510 (2^(32 - 23) - 2) pod IP addresses.	A subnet prefix. The default value is `23`.
`networking.serviceNetwork`	The IP address block for services. The default value is `172.30.0.0/16`. The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network.	An array with an IP address block in CIDR format. For example: networking: serviceNetwork: - 172.30.0.0/16
`networking.machineNetwork`	The IP address blocks for machines. If you specify multiple IP address blocks, the blocks must not overlap.	An array of objects. For example: networking: machineNetwork: - cidr: 10.0.0.0/16
`networking.machineNetwork.cidr`	Required if you use `networking.machineNetwork`. An IP address block. The default value is `10.0.0.0/16` for all platforms other than libvirt. For libvirt, the default value is `192.168.126.0/24`.	An IP network block in CIDR notation. For example, `10.0.0.0/16`. Note Set the `networking.machineNetwork` to match the CIDR that the preferred NIC resides in.

1.1.8.1.3. Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Table 1.9. Optional parameters
Parameter	Description	Values
`additionalTrustBundle`	A PEM-encoded X.509 certificate bundle that is added to the nodes' trusted certificate store. This trust bundle may also be used when a proxy has been configured.	String
`compute`	The configuration for the machines that comprise the compute nodes.	Array of machine-pool objects. For details, see the following "Machine-pool" table.
`compute.architecture`	Determines the instruction set architecture of the machines in the pool. Currently, heteregeneous clusters are not supported, so all pools must specify the same architecture. Valid values are `amd64` (the default).	String
`compute.hyperthreading`	Whether to enable or disable simultaneous multithreading, or `hyperthreading`, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.	`Enabled` or `Disabled`
`compute.name`	Required if you use `compute`. The name of the machine pool.	`worker`
`compute.platform`	Required if you use `compute`. Use this parameter to specify the cloud provider to host the worker machines. This parameter value must match the `controlPlane.platform` parameter value.	`aws`, `azure`, `gcp`, `openstack`, `ovirt`, `vsphere`, or `{}`
`compute.replicas`	The number of compute machines, which are also known as worker machines, to provision.	A positive integer greater than or equal to `2`. The default value is `3`.
`controlPlane`	The configuration for the machines that comprise the control plane.	Array of `MachinePool` objects. For details, see the following "Machine-pool" table.
`controlPlane.architecture`	Determines the instruction set architecture of the machines in the pool. Currently, heterogeneous clusters are not supported, so all pools must specify the same architecture. Valid values are `amd64` (the default).	String
`controlPlane.hyperthreading`	Whether to enable or disable simultaneous multithreading, or `hyperthreading`, on control plane machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.	`Enabled` or `Disabled`
`controlPlane.name`	Required if you use `controlPlane`. The name of the machine pool.	`master`
`controlPlane.platform`	Required if you use `controlPlane`. Use this parameter to specify the cloud provider that hosts the control plane machines. This parameter value must match the `compute.platform` parameter value.	`aws`, `azure`, `gcp`, `openstack`, `ovirt`, `vsphere`, or `{}`
`controlPlane.replicas`	The number of control plane machines to provision.	The only supported value is `3`, which is the default value.
`fips`	Enable or disable FIPS mode. The default is `false` (disabled). If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead. Note If you are using Azure File storage, you cannot enable FIPS mode.	`false` or `true`
`imageContentSources`	Sources and repositories for the release-image content.	Array of objects. Includes a `source` and, optionally, `mirrors`, as described in the following rows of this table.
`imageContentSources.source`	Required if you use `imageContentSources`. Specify the repository that users refer to, for example, in image pull specifications.	String
`imageContentSources.mirrors`	Specify one or more repositories that may also contain the same images.	Array of strings
`publish`	How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes.	`Internal` or `External`. The default value is `External`. Setting this field to `Internal` is not supported on non-cloud platforms. Important If the value of the field is set to `Internal`, the cluster will become non-functional. For more information, refer to BZ#1953035.
`sshKey`	The SSH key to authenticate access to your cluster machines. Note For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your `ssh-agent` process uses.	For example, `sshKey: ssh-ed25519 AAAA..`.

1.1.8.2. Sample `install-config.yaml` file for bare metal

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OpenShiftSDN
  serviceNetwork: 11
  - 172.30.0.0/16
platform:
  none: {} 12
fips: false 13
pullSecret: '{"auths": ...}' 14
sshKey: 'ssh-ed25519 AAAA...' 15

1: The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 5: The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Although both sections currently define a single machine pool, it is possible that future versions of OpenShift Container Platform will support defining multiple compute pools during installation. Only one control plane pool is used.
3 6: Whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note
Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.
Important
If you disable hyperthreading, whether in the BIOS or in the install-config.yaml, ensure that your capacity planning accounts for the dramatically decreased machine performance.
4: You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OpenShift Container Platform.
7: The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8: The cluster name that you specified in your DNS records.
9: A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
10: The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.
11: The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
12: You must set the platform to none. You cannot provide additional platform configuration variables for bare metal infrastructure.
13: Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
14: The pull secret that you obtained from the Pull Secret page on the Red Hat OpenShift Cluster Manager site. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.
15: The public portion of the default SSH key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note
For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

1.1.8.3. Configuring the cluster-wide proxy during installation

Production environments can deny direct access to the Internet and instead have an HTTP or HTTPS proxy available. You can configure a new OpenShift Container Platform cluster to use a proxy by configuring the proxy settings in the install-config.yaml file.

Note

For bare metal installations, if you do not assign node IP addresses from the range that is specified in the networking.machineNetwork[].cidr field in the install-config.yaml file, you must include them in the proxy.noProxy field.

Prerequisites

An existing install-config.yaml file.
Review the sites that your cluster requires access to and determine whether any need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. Add sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.
Note
The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.
For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

Edit your install-config.yaml file and add the proxy settings. For example:
```
apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> 1
  httpsProxy: http://<username>:<pswd>@<ip>:<port> 2
  noProxy: example.com 3
additionalTrustBundle: | 4
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...
```
1
A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpProxy value.
2
A proxy URL to use for creating HTTPS connections outside the cluster. If this field is not specified, then httpProxy is used for both HTTP and HTTPS connections. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpsProxy value.
3
A comma-separated list of destination domain names, domains, IP addresses, or other network CIDRs to exclude proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass proxy for all destinations.
4
If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the Proxy object’s trustedCA field. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must provide the MITM CA certificate.
Note
The installation program does not support the proxy readinessEndpoints field.
Save the file and reference it when installing OpenShift Container Platform.

The installation program creates a cluster-wide proxy that is named cluster that uses the proxy settings in the provided install-config.yaml file. If no proxy settings are provided, a cluster Proxy object is still created, but it will have a nil spec.

Note

Only the Proxy object named cluster is supported, and no additional proxies can be created.

1.1.9. Configuring a three-node cluster

You can optionally install and run three-node clusters in OpenShift Container Platform with no workers. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for development, production, and testing.

Procedure

Edit the install-config.yaml file to set the number of compute replicas, which are also known as worker replicas, to 0, as shown in the following compute stanza:
```
compute:
- name: worker
  platform: {}
  replicas: 0
```

1.1.10. Creating the Kubernetes manifest and Ignition config files

Because you must modify some cluster definition files and manually start the cluster machines, you must generate the Kubernetes manifest and Ignition config files that the cluster needs to make its machines.

Important

The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending node-bootstrapper certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.

Prerequisites

Obtain the OpenShift Container Platform installation program.
Create the install-config.yaml installation configuration file.

Procedure

Generate the Kubernetes manifests for the cluster:
```
$ ./openshift-install create manifests --dir=<installation_directory> 1
```
Example output
```
INFO Consuming Install Config from target directory
WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings
```
1
For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
Because you create your own compute machines later in the installation process, you can safely ignore this warning.

Warning

If you are running a three-node cluster, skip the following step to allow the masters to be schedulable.

Modify the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file to prevent pods from being scheduled on the control plane machines:
1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
2. Locate the mastersSchedulable parameter and set its value to False.
3. Save and exit the file.

Obtain the Ignition config files:

$ ./openshift-install create ignition-configs --dir=<installation_directory> 1

1: For <installation_directory>, specify the same installation directory.

The following files are generated in the directory:

.
├── auth
│   ├── kubeadmin-password
│   └── kubeconfig
├── bootstrap.ign
├── master.ign
├── metadata.json
└── worker.ign

1.1.11. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. Follow either the steps to use an ISO image or network PXE booting to create the machines.

1.1.11.1. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines using an ISO image

Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use an ISO image to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Have access to an HTTP server that you can access from your computer and that the machines that you create can access.

Procedure

Upload the control plane, compute, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use ISO images for this procedure. RHCOS qcow2 images are not supported for bare metal installs.
You must download the ISO file and the RAW disk file. Those file names resemble the following examples:
- ISO: rhcos-<version>-installer.<architecture>.iso
- Compressed metal RAW: rhcos-<version>-metal.<architecture>.raw.gz
Upload either the RAW RHCOS image file to your HTTP server and note its URL.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Use the ISO to start the RHCOS installation. Use one of the following installation options:
- Burn the ISO image to a disk and boot it directly.
- Use ISO redirection via a LOM interface.
After the instance boots, press the TAB or E key to edit the kernel command line.
Add the parameters to the kernel command line:
```
coreos.inst=yes
coreos.inst.install_dev=sda 1
coreos.inst.image_url=<image_URL> 2
coreos.inst.ignition_url=http://example.com/config.ign 3
ip=<dhcp or static IP address> 4 5
bond=<bonded_interface> 6
```
1
Specify the block device of the system to install to.
2
Specify the URL of the RAW image that you uploaded to your server.
3
Specify the URL of the Ignition config file for this machine type.
4
Set ip=dhcp or set an individual static IP address (ip=) and DNS server (nameserver=) on each node. See Configure advanced networking for details.
5
If you use multiple network interfaces or DNS servers, see Configure advanced networking for details on how to configure them.
6
Optionally, you can bond multiple network interfaces to a single interface using the bond= option, as described in Configure advanced networking.
Press Enter to complete the installation. After RHCOS installs, the system reboots. After the system reboots, it applies the Ignition config file that you specified.
Continue to create the machines for your cluster.
Important
You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

1.1.11.1.1. Configure advanced networking

If you install Red Hat Enterprise Linux CoreOS (RHCOS) from an ISO image, you can add kernel arguments when you boot that image to configure the node’s networking. The following table describes and illustrates how to use those kernel arguments.

Table 1.10. Configure advanced networking
Description	Examples
To configure an IP address, either use DHCP (`ip=dhcp`) or set an individual static IP address (`ip=<host_ip>`). Then identify the DNS server IP address (`nameserver=<dns_ip>`) on each node. This example sets: The node’s IP address to `10.10.10.2` The gateway address to `10.10.10.254` The netmask to `255.255.255.0` The hostname to `core0.example.com` The DNS server address to `4.4.4.41`	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none nameserver=4.4.4.41
Specify multiple network interfaces by specifying multiple `ip=` entries.	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can combine DHCP and static IP configurations on systems with multiple network interfaces.	ip=enp1s0:dhcp ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can provide multiple DNS servers by adding a `nameserver=` entry for each server.	nameserver=1.1.1.1 nameserver=8.8.8.8
Bonding multiple network interfaces to a single interface is optionally supported using the `bond=` option. In these two examples: The syntax for configuring a bonded interface is: `bond=name[:network_interfaces][:options]` name is the bonding device name (`bond0`), network_interfaces represents a comma-separated list of physical (ethernet) interfaces (`em1,em2`), and options is a comma-separated list of bonding options. (Enter `modinfo bonding` to see available options.) When you create a bonded interface using `bond=`, you must specify how the IP address is assigned and other information for the bonded interface.	To configure the bonded interface to use DHCP, set the bond’s IP address to `dhcp`. For example: bond=bond0:em1,em2:mode=active-backup ip=bond0:dhcp To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: bond=bond0:em1,em2:mode=active-backup ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none Important When using the advanced networking options, you could encounter issues during the first boot of RHCOS where the statically configured address is not present or not activated properly. In such cases, you might need to manually reboot the RHCOS machine to workaround this problem. In newer versions of RHCOS, this issue is resolved. See BZ#1902584 for additional details.

1.1.11.2. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines by PXE or iPXE booting

Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use PXE or iPXE booting to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Familiarity configuring the necessary DHCP, TFTP, and HTTP services for providing PXE or iPXE infrastructure.
Have access to an HTTP server and TFTP server that you can access from your computer.

Procedure

Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Obtain the compressed metal RAW image, kernel and initramfs files from the Product Downloads page on the Red Hat customer portal or the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use RAW images for this procedure. RHCOS qcow2 images are not supported for bare metal installs.
The file names contain the OpenShift Container Platform version number. They resemble the following examples:
- Compressed metal RAW image: rhcos-<version>-<architecture>-metal.<architecture>.raw.gz
- kernel: rhcos-<version>-<architecture>-installer-kernel-<architecture>
- initramfs: rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img
Upload the RAW image to your HTTP server.
Upload the additional files that are required for your booting method:
- For traditional PXE, upload the kernel and initramfs files to your TFTP server.
- For iPXE, upload the kernel and initramfs files to your HTTP server.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
Configure PXE or iPXE installation for the RHCOS images.
Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:
- For PXE:
```
DEFAULT pxeboot
TIMEOUT 20
PROMPT 0
LABEL pxeboot
    KERNEL rhcos-<version>-<architecture>-installer-kernel-<architecture> 1
    APPEND ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 2 3
```
  1
  Specify the location of the kernel file available on your TFTP server.
  2
  If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
  3
  Specify locations of the RHCOS files that you uploaded to your HTTP or TFTP server. The initrd parameter value is the location of the initramfs file on your TFTP server. The coreos.inst.image_url parameter value is the location of the compressed metal RAW image on your HTTP server, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file on your HTTP server.
  Note
  This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the APPEND line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux?.
- For iPXE:
```
kernel  http://<HTTP_server>/rhcos-<version>-<architecture>-installer-kernel-<architecture> ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
initrd http://<HTTP_server>/rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img 3
boot
```
  1
  Specify locations of the RHCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd parameter value references the name of the initramfs file that is supplied on the following initrd line, the coreos.inst.image_url parameter value is the location of the compressed metal RAW image, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.
  2
  If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
  3
  Specify the location of the initramfs file that you uploaded to your HTTP server.
  Note
  This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the kernel line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux?.
If you use UEFI, perform the following actions:
1. Provide the EFI binaries and grub.cfg file that are required for booting the system. You need the shim.efi binary and the grubx64.efi binary.
  - Extract the necessary EFI binaries by mounting the RHCOS ISO on your host and then mounting the images/efiboot.img file to your host. From the efiboot.img mount point, you then copy the EFI/redhat/shimx64.efi and EFI/redhat/grubx64.efi files to your TFTP server.
    # mkdir -p /mnt/{iso,efiboot} # mount -o loop rhcos-installer.x86_64.iso /mnt/iso # mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot # cp /mnt/efiboot/EFI/redhat/{shimx64.efi,grubx64.efi} . # umount /mnt/{efiboot,iso}
2. Copy the EFI/redhat/grub.cfg file that is included in the RHCOS ISO to your TFTP server.
3. Edit the grub.cfg file to include the following arguments:
```
menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os {
	linux rhcos-<version>-<architecture>-installer-kernel-<architecture> nomodeset rd.neednet=1 coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1
	initrd rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img 2
}
```
  1
  The first argument to the linux line item is the location of the kernel file that you uploaded to your TFTP server. For the coreos.inst.image_url parameter value, specify the location of the compressed metal RAW image that you uploaded to your HTTP server. For the coreos.inst.ignition_url paramter, specify the location of the bootstrap Ignition config file that you uploaded to your HTTP server.
  2
  Specify the location of the initramfs file that you uploaded to your TFTP server.
Continue to create the machines for your cluster.
Important
You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

1.1.12. Creating the cluster

To create the OpenShift Container Platform cluster, you wait for the bootstrap process to complete on the machines that you provisioned by using the Ignition config files that you generated with the installation program.

Prerequisites

Create the required infrastructure for the cluster.
You obtained the installation program and generated the Ignition config files for your cluster.
You used the Ignition config files to create RHCOS machines for your cluster.
Your machines have direct Internet access or have an HTTP or HTTPS proxy available.

Procedure

Monitor the bootstrap process:
```
$ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ 1
    --log-level=info 2
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
2
To view different installation details, specify warn, debug, or error instead of info.
Example output
```
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.18.3 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources
```
The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.
After bootstrap process is complete, remove the bootstrap machine from the load balancer.
Important
You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the machine itself.

1.1.13. Logging in to the cluster

You can log in to your cluster as a default system user by exporting the cluster kubeconfig file. The kubeconfig file contains information about the cluster that is used by the CLI to connect a client to the correct cluster and API server. The file is specific to a cluster and is created during OpenShift Container Platform installation.

Prerequisites

Deploy an OpenShift Container Platform cluster.
Install the oc CLI.

Procedure

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

1.1.14. Approving the certificate signing requests for your machines

When you add machines to a cluster, two pending certificate signing requests (CSRs) are generated for each machine that you added. You must confirm that these CSRs are approved or, if necessary, approve them yourself. The client requests must be approved first, followed by the server requests.

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.18.3
master-1  Ready     master  63m  v1.18.3
master-2  Ready     master  64m  v1.18.3
worker-0  NotReady  worker  76s  v1.18.3
worker-1  NotReady  worker  70s  v1.18.3

The output lists all of the machines that you created.

Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
...

In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:
Note
Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. Once the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
```

Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
...

If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
```

After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

Note

It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

For more information on CSRs, see Certificate Signing Requests.

1.1.15. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

Your control plane has initialized.

Procedure

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                 VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                       4.5.4     True        False         False      69s
cloud-credential                     4.5.4     True        False         False      12m
cluster-autoscaler                   4.5.4     True        False         False      11m
console                              4.5.4     True        False         False      46s
dns                                  4.5.4     True        False         False      11m
image-registry                       4.5.4     True        False         False      5m26s
ingress                              4.5.4     True        False         False      5m36s
kube-apiserver                       4.5.4     True        False         False      8m53s
kube-controller-manager              4.5.4     True        False         False      7m24s
kube-scheduler                       4.5.4     True        False         False      12m
machine-api                          4.5.4     True        False         False      12m
machine-config                       4.5.4     True        False         False      7m36s
marketplace                          4.5.4     True        False         False      7m54m
monitoring                           4.5.4     True        False         False      7h54s
network                              4.5.4     True        False         False      5m9s
node-tuning                          4.5.4     True        False         False      11m
openshift-apiserver                  4.5.4     True        False         False      11m
openshift-controller-manager         4.5.4     True        False         False      5m943s
openshift-samples                    4.5.4     True        False         False      3m55s
operator-lifecycle-manager           4.5.4     True        False         False      11m
operator-lifecycle-manager-catalog   4.5.4     True        False         False      11m
service-ca                           4.5.4     True        False         False      11m
service-catalog-apiserver            4.5.4     True        False         False      5m26s
service-catalog-controller-manager   4.5.4     True        False         False      5m25s
storage                              4.5.4     True        False         False      5m30s

Configure the Operators that are not available.

1.1.15.1. Image registry removed during installation

On platforms that do not provide shareable object storage, the OpenShift Image Registry Operator bootstraps itself as Removed. This allows openshift-installer to complete installations on these platform types.

After installation, you must edit the Image Registry Operator configuration to switch the managementState from Removed to Managed.

Note

The Prometheus console provides an ImageRegistryRemoved alert, for example:

"Image Registry has been removed. ImageStreamTags, BuildConfigs and DeploymentConfigs which reference ImageStreamTags may not work as expected. Please configure storage and update the config to Managed state by editing configs.imageregistry.operator.openshift.io."

1.1.15.2. Image registry storage configuration

The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.

Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

1.1.15.2.1. Configuring registry storage for bare metal

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites

Cluster administrator permissions.
A cluster on bare metal.
Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.
Important
OpenShift Container Platform supports ReadWriteOnce access for image registry storage when you have only one replica. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.
Must have 100Gi capacity.

Procedure

To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.
Note
When using shared storage, review your security settings to prevent outside access.
Verify that you do not have a registry pod:
```
$ oc get pod -n openshift-image-registry
```
Note
If the storage type is emptyDIR, the replica number cannot be greater than 1.
Check the registry configuration:
```
$ oc edit configs.imageregistry.operator.openshift.io
```
Example output
```
storage:
  pvc:
    claim:
```
Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.
Check the clusteroperator status:
```
$ oc get clusteroperator image-registry
```

1.1.15.2.2. Configuring storage for the image registry in non-production clusters

You must configure storage for the Image Registry Operator. For non-production clusters, you can set the image registry to an empty directory. If you do so, all images are lost if you restart the registry.

Procedure

To set the image registry storage to an empty directory:
```
$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'
```
Warning
Configure this option for only non-production clusters.
If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:
```
Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found
```
Wait a few minutes and run the command again.
Ensure that your registry is set to managed to enable building and pushing of images.
- Run:
```
$ oc edit configs.imageregistry/cluster
```
  Then, change the line
```
managementState: Removed
```
  to
```
managementState: Managed
```

1.1.15.2.3. Configuring block registry storage for bare metal

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Important

Block storage volumes are supported but not recommended for use with the image registry on production clusters. An installation where the registry is configured on block storage is not highly available because the registry cannot have more than one replica.

Procedure

To set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy and runs with only one (1) replica:
```
$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
```
Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.
Edit the registry configuration so that it references the correct PVC.

1.1.16. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

Your control plane has initialized.
You have completed the initial Operator configuration.

Procedure

Confirm that all the cluster components are online with the following command:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.5.4     True        False         False      7m56s
cloud-credential                           4.5.4     True        False         False      31m
cluster-autoscaler                         4.5.4     True        False         False      16m
console                                    4.5.4     True        False         False      10m
csi-snapshot-controller                    4.5.4     True        False         False      16m
dns                                        4.5.4     True        False         False      22m
etcd                                       4.5.4     False       False         False      25s
image-registry                             4.5.4     True        False         False      16m
ingress                                    4.5.4     True        False         False      16m
insights                                   4.5.4     True        False         False      17m
kube-apiserver                             4.5.4     True        False         False      19m
kube-controller-manager                    4.5.4     True        False         False      20m
kube-scheduler                             4.5.4     True        False         False      20m
kube-storage-version-migrator              4.5.4     True        False         False      16m
machine-api                                4.5.4     True        False         False      22m
machine-config                             4.5.4     True        False         False      22m
marketplace                                4.5.4     True        False         False      16m
monitoring                                 4.5.4     True        False         False      10m
network                                    4.5.4     True        False         False      23m
node-tuning                                4.5.4     True        False         False      23m
openshift-apiserver                        4.5.4     True        False         False      17m
openshift-controller-manager               4.5.4     True        False         False      15m
openshift-samples                          4.5.4     True        False         False      16m
operator-lifecycle-manager                 4.5.4     True        False         False      22m
operator-lifecycle-manager-catalog         4.5.4     True        False         False      22m
operator-lifecycle-manager-packageserver   4.5.4     True        False         False      18m
service-ca                                 4.5.4     True        False         False      23m
service-catalog-apiserver                  4.5.4     True        False         False      23m
service-catalog-controller-manager         4.5.4     True        False         False      23m
storage                                    4.5.4     True        False         False      17m

Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

$ ./openshift-install --dir=<installation_directory> wait-for install-complete 1

1: For <installation_directory>, specify the path to the directory that you stored the installation files in.

Example output

INFO Waiting up to 30m0s for the cluster to initialize...

The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

Important

Confirm that the Kubernetes API server is communicating with the pods.

To view a list of all pods, use the following command:

$ oc get pods --all-namespaces

Example output

NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
...

View the logs for a pod that is listed in the output of the previous command by using the following command:
```
$ oc logs <pod_name> -n <namespace> 1
```
1
Specify the pod name and namespace, as shown in the output of the previous command.
If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

1.1.17. Next steps

Customize your cluster.
If necessary, you can opt out of remote health reporting.
Set up your registry and configure registry storage.

1.2. Installing a cluster on bare metal with network customizations

In OpenShift Container Platform version 4.5, you can install a cluster on bare metal infrastructure that you provision with customized network configuration options. By customizing your network configuration, your cluster can coexist with existing IP address allocations in your environment and integrate with existing MTU and VXLAN configurations.

You must set most of the network configuration parameters during installation, and you can modify only kubeProxy configuration parameters in a running cluster.

1.2.1. Prerequisites

Review details about the OpenShift Container Platform installation and update processes.
If you use a firewall, you must configure it to access Red Hat Insights.

1.2.2. Internet and Telemetry access for OpenShift Container Platform

You must have Internet access to:

Access the Red Hat OpenShift Cluster Manager page to download the installation program and perform subscription management. If the cluster has Internet access and you do not disable Telemetry, that service automatically entitles your cluster.
Access Quay.io to obtain the packages that are required to install your cluster.
Obtain the packages that are required to perform cluster updates.

Important

1.2.3. Machine requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

1.2.3.1. Required machines

The smallest OpenShift Container Platform clusters require the following hosts:

One temporary bootstrap machine
Three control plane, or master, machines
At least two compute machines, which are also known as worker machines. If you are running a three-node cluster, running zero compute machines is supported. Running one compute machine is not supported.

Note

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Important

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.

Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

1.2.3.2. Network connectivity requirements

1.2.3.3. Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

Machine	Operating System	vCPU ^[1]	Virtual RAM	Storage
Bootstrap	RHCOS	4	16 GB	120 GB
Control plane	RHCOS	4	16 GB	120 GB
Compute	RHCOS or RHEL 7.8 - 7.9	2	8 GB	120 GB

1 vCPU is equivalent to 1 physical core when simultaneous multithreading (SMT), or hyperthreading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.

1.2.3.4. Certificate signing requests management

1.2.4. Creating the user-provisioned infrastructure

Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Review the OpenShift Container Platform 4.x Tested Integrations page before you create the supporting infrastructure for your cluster.

Procedure

Configure DHCP or set static IP addresses on each node.
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

1.2.4.1. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 1.11. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`1936`	Metrics
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101` and the Cluster Version Operator on port `9099`.
	`10250`-`10259`	The default ports that Kubernetes reserves
	`10256`	openshift-sdn
UDP	`4789`	VXLAN and Geneve
	`6081`	VXLAN and Geneve
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101`.
TCP/UDP	`30000`-`32767`	Kubernetes node port

Table 1.12. All machines to control plane
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 1.13. Control plane machines to control plane machines
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

Important

OpenShift Container Platform requires all nodes to have internet access to pull images for platform containers and provide telemetry data to Red Hat.

Load balancers

Before you install OpenShift Container Platform, you must provision two load balancers that meet the following requirements:

API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
A stateless load balancing algorithm. The options vary based on the load balancer implementation.

Note

Session persistence is not required for the API load balancer to function properly.

Configure the following ports on both the front and back of the load balancers:

Table 1.14. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`6443`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the `/readyz` endpoint for the API server health check probe.	X	X	Kubernetes API server
`22623`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.	X		Machine config server

Note

Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.
A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.

Configure the following ports on both the front and back of the load balancers:

Table 1.15. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`443`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTPS traffic
`80`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTP traffic

Tip

If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

Note

A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes.

NTP configuration

If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

Configuring chrony time service

1.2.4.2. User-provisioned DNS requirements

Table 1.16. Required DNS records
Component	Record	Description
Kubernetes API	`api.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Kubernetes API	`api-int.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster. Important The API server must be able to resolve the worker nodes by the host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.
Routes	`*.apps.<cluster_name>.<base_domain>.`	Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Bootstrap	`bootstrap.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.
Master hosts	`<master><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the master nodes. These records must be resolvable by the nodes within the cluster.
Worker hosts	`<worker><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Tip

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

Example 1.3. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Example 1.4. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.example.com.
5	IN	PTR	api-int.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

1.2.5. Generating an SSH private key and adding it to the agent

Note

In a production environment, you require disaster recovery and debugging.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

Note

You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs.

Procedure

If you do not have an SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:
```
$ ssh-keygen -t ed25519 -N '' \
    -f <path>/<file_name> 1
```
1
Specify the path and file name, such as ~/.ssh/id_rsa, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
Running this command generates an SSH key that does not require a password in the location that you specified.
Note
If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"
```
Example output
```
Agent pid 31874
```

If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> 1
```
Example output
```
Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
```
1
Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

When you install OpenShift Container Platform, provide the SSH public key to the installation program.

1.2.6. Obtaining the installation program

Before you install OpenShift Container Platform, download the installation file on a local computer.

Prerequisites

You must install the cluster from a computer that uses Linux or macOS.
You need 500 MB of local disk space to download the installation program.

Procedure

Access the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
Navigate to the page for your installation type, download the installation program for your operating system, and place the file in the directory where you will store the installation configuration files.
Important
The installation program creates several files on the computer that you use to install your cluster. You must keep both the installation program and the files that the installation program creates after you finish installing the cluster.
Important
Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. You must complete the OpenShift Container Platform uninstallation procedures outlined for your specific cloud provider to remove your cluster entirely.
Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:
```
$ tar xvf <installation_program>.tar.gz
```
From the Pull Secret page on the Red Hat OpenShift Cluster Manager site, download your installation pull secret as a .txt file. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.

1.2.7. Installing the CLI by downloading the binary

You can install the OpenShift CLI (oc) in order to interact with OpenShift Container Platform from a command-line interface. You can install oc on Linux, Windows, or macOS.

Important

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.5. Download and install the new version of oc.

1.2.7.1. Installing the CLI on Linux

You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command line interface section, select Linux from the drop-down menu and click Download command-line tools.
Unpack the archive:
```
$ tar xvzf <file>
```
Place the oc binary in a directory that is on your PATH.
To check your PATH, execute the following command:
```
$ echo $PATH
```

After you install the CLI, it is available using the oc command:

$ oc <command>

1.2.7.2. Installing the CLI on Windows

You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command line interface section, select Windows from the drop-down menu and click Download command-line tools.
Unzip the archive with a ZIP program.
Move the oc binary to a directory that is on your PATH.
To check your PATH, open the command prompt and execute the following command:
```
C:\> path
```

After you install the CLI, it is available using the oc command:

C:\> oc <command>

1.2.7.3. Installing the CLI on macOS

You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.

Procedure

Navigate to the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site.
Select your infrastructure provider, and, if applicable, your installation type.
In the Command line interface section, select MacOS from the drop-down menu and click Download command-line tools.
Unpack and unzip the archive.
Move the oc binary to a directory on your PATH.
To check your PATH, open a terminal and execute the following command:
```
$ echo $PATH
```

After you install the CLI, it is available using the oc command:

$ oc <command>

1.2.8. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

Obtain the OpenShift Container Platform installation program and the access token for your cluster.

Procedure

Create an installation directory to store your required installation assets in:
```
$ mkdir <installation_directory>
```
Important
You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.
Customize the following install-config.yaml file template and save it in the <installation_directory>.
Note
You must name this configuration file install-config.yaml.
Back up the install-config.yaml file so that you can use it to install multiple clusters.
Important
The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

1.2.8.1. Installation configuration parameters

Note

After installation, you cannot modify these parameters in the install-config.yaml file.

Important

1.2.8.1.1. Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 1.17. Required parameters
Parameter	Description	Values
`apiVersion`	The API version for the `install-config.yaml` content. The current version is `v1`. The installer may also support older API versions.	String
`baseDomain`	The base domain of your cloud provider. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the `baseDomain` and `metadata.name` parameter values that uses the `<metadata.name>.<baseDomain>` format.	A fully-qualified domain or subdomain name, such as `example.com`.
`metadata`	Kubernetes resource `ObjectMeta`, from which only the `name` parameter is consumed.	Object
`metadata.name`	The name of the cluster. DNS records for the cluster are all subdomains of `{{.metadata.name}}.{{.baseDomain}}`.	String of lowercase letters, hyphens (`-`), and periods (`.`), such as `dev`.
`platform`	The configuration for the specific platform upon which to perform the installation: `aws`, `baremetal`, `azure`, `openstack`, `ovirt`, `vsphere`. For additional information about `platform.<platform>` parameters, consult the following table for your specific platform.	Object
`pullSecret`	Get a pull secret from https://cloud.redhat.com/openshift/install/pull-secret to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io.	{ "auths":{ "cloud.openshift.com":{ "auth":"b3Blb=", "email":"you@example.com" }, "quay.io":{ "auth":"b3Blb=", "email":"you@example.com" } } }

1.2.8.1.2. Network configuration parameters

Only IPv4 addresses are supported.

Table 1.18. Network parameters
Parameter	Description	Values
`networking`	The configuration for the cluster network.	Object Note You cannot modify parameters specified by the `networking` object after installation.
`networking.networkType`	The cluster network provider Container Network Interface (CNI) plug-in to install.	Either `OpenShiftSDN` or `OVNKubernetes`. The default value is `OpenShiftSDN`.
`networking.clusterNetwork`	The IP address blocks for pods. The default value is `10.128.0.0/14` with a host prefix of `/23`. If you specify multiple IP address blocks, the blocks must not overlap.	An array of objects. For example: networking: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23
`networking.clusterNetwork.cidr`	Required if you use `networking.clusterNetwork`. An IP address block. An IPv4 network.	An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between `0` and `32`.
`networking.clusterNetwork.hostPrefix`	The subnet prefix length to assign to each individual node. For example, if `hostPrefix` is set to `23` then each node is assigned a `/23` subnet out of the given `cidr`. A `hostPrefix` value of `23` provides 510 (2^(32 - 23) - 2) pod IP addresses.	A subnet prefix. The default value is `23`.
`networking.serviceNetwork`	The IP address block for services. The default value is `172.30.0.0/16`. The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network.	An array with an IP address block in CIDR format. For example: networking: serviceNetwork: - 172.30.0.0/16
`networking.machineNetwork`	The IP address blocks for machines. If you specify multiple IP address blocks, the blocks must not overlap.	An array of objects. For example: networking: machineNetwork: - cidr: 10.0.0.0/16
`networking.machineNetwork.cidr`	Required if you use `networking.machineNetwork`. An IP address block. The default value is `10.0.0.0/16` for all platforms other than libvirt. For libvirt, the default value is `192.168.126.0/24`.	An IP network block in CIDR notation. For example, `10.0.0.0/16`. Note Set the `networking.machineNetwork` to match the CIDR that the preferred NIC resides in.

1.2.8.1.3. Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Table 1.19. Optional parameters
Parameter	Description	Values
`additionalTrustBundle`	A PEM-encoded X.509 certificate bundle that is added to the nodes' trusted certificate store. This trust bundle may also be used when a proxy has been configured.	String
`compute`	The configuration for the machines that comprise the compute nodes.	Array of machine-pool objects. For details, see the following "Machine-pool" table.
`compute.architecture`	Determines the instruction set architecture of the machines in the pool. Currently, heteregeneous clusters are not supported, so all pools must specify the same architecture. Valid values are `amd64` (the default).	String
`compute.hyperthreading`	Whether to enable or disable simultaneous multithreading, or `hyperthreading`, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.	`Enabled` or `Disabled`
`compute.name`	Required if you use `compute`. The name of the machine pool.	`worker`
`compute.platform`	Required if you use `compute`. Use this parameter to specify the cloud provider to host the worker machines. This parameter value must match the `controlPlane.platform` parameter value.	`aws`, `azure`, `gcp`, `openstack`, `ovirt`, `vsphere`, or `{}`
`compute.replicas`	The number of compute machines, which are also known as worker machines, to provision.	A positive integer greater than or equal to `2`. The default value is `3`.
`controlPlane`	The configuration for the machines that comprise the control plane.	Array of `MachinePool` objects. For details, see the following "Machine-pool" table.
`controlPlane.architecture`	Determines the instruction set architecture of the machines in the pool. Currently, heterogeneous clusters are not supported, so all pools must specify the same architecture. Valid values are `amd64` (the default).	String
`controlPlane.hyperthreading`	Whether to enable or disable simultaneous multithreading, or `hyperthreading`, on control plane machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.	`Enabled` or `Disabled`
`controlPlane.name`	Required if you use `controlPlane`. The name of the machine pool.	`master`
`controlPlane.platform`	Required if you use `controlPlane`. Use this parameter to specify the cloud provider that hosts the control plane machines. This parameter value must match the `compute.platform` parameter value.	`aws`, `azure`, `gcp`, `openstack`, `ovirt`, `vsphere`, or `{}`
`controlPlane.replicas`	The number of control plane machines to provision.	The only supported value is `3`, which is the default value.
`fips`	Enable or disable FIPS mode. The default is `false` (disabled). If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead. Note If you are using Azure File storage, you cannot enable FIPS mode.	`false` or `true`
`imageContentSources`	Sources and repositories for the release-image content.	Array of objects. Includes a `source` and, optionally, `mirrors`, as described in the following rows of this table.
`imageContentSources.source`	Required if you use `imageContentSources`. Specify the repository that users refer to, for example, in image pull specifications.	String
`imageContentSources.mirrors`	Specify one or more repositories that may also contain the same images.	Array of strings
`publish`	How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes.	`Internal` or `External`. The default value is `External`. Setting this field to `Internal` is not supported on non-cloud platforms. Important If the value of the field is set to `Internal`, the cluster will become non-functional. For more information, refer to BZ#1953035.
`sshKey`	The SSH key to authenticate access to your cluster machines. Note For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your `ssh-agent` process uses.	For example, `sshKey: ssh-ed25519 AAAA..`.

1.2.8.2. Sample `install-config.yaml` file for bare metal

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OpenShiftSDN
  serviceNetwork: 11
  - 172.30.0.0/16
platform:
  none: {} 12
fips: false 13
pullSecret: '{"auths": ...}' 14
sshKey: 'ssh-ed25519 AAAA...' 15

1: The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 5: The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Although both sections currently define a single machine pool, it is possible that future versions of OpenShift Container Platform will support defining multiple compute pools during installation. Only one control plane pool is used.
3 6: Whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note
Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.
Important
If you disable hyperthreading, whether in the BIOS or in the install-config.yaml, ensure that your capacity planning accounts for the dramatically decreased machine performance.
4: You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OpenShift Container Platform.
7: The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8: The cluster name that you specified in your DNS records.
9: A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
10: The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.
11: The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
12: You must set the platform to none. You cannot provide additional platform configuration variables for bare metal infrastructure.
13: Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
14: The pull secret that you obtained from the Pull Secret page on the Red Hat OpenShift Cluster Manager site. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OpenShift Container Platform components.
15: The public portion of the default SSH key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note
For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.

1.2.8.3. Network configuration parameters

You can modify your cluster network configuration parameters in the install-config.yaml configuration file. The following table describes the parameters.

Note

You cannot modify these parameters in the install-config.yaml file after installation.

Table 1.20. Required network parameters
Parameter	Description	Value
`networking.networkType`	The default Container Network Interface (CNI) network provider plug-in to deploy. The `OpenShiftSDN` plug-in is the only plug-in supported in OpenShift Container Platform 4.5.	The default value is `OpenShiftSDN`.
`networking.clusterNetwork[].cidr`	A block of IP addresses from which pod IP addresses are allocated. The `OpenShiftSDN` network plug-in supports multiple cluster networks. The address blocks for multiple cluster networks must not overlap. Select address pools large enough to fit your anticipated workload.	An IP address allocation in CIDR format. The default value is `10.128.0.0/14`.
`networking.clusterNetwork[].hostPrefix`	The subnet prefix length to assign to each individual node. For example, if `hostPrefix` is set to `23`, then each node is assigned a `/23` subnet out of the given `cidr`, allowing for 510 (2^(32 - 23) - 2) pod IP addresses.	A subnet prefix. The default value is `23`.
`networking.serviceNetwork[]`	A block of IP addresses for services. `OpenShiftSDN` allows only one `serviceNetwork` block. The address block must not overlap with any other network block.	An IP address allocation in CIDR format. The default value is `172.30.0.0/16`.
`networking.machineNetwork[].cidr`	A block of IP addresses assigned to nodes created by the OpenShift Container Platform installation program while installing the cluster. The address block must not overlap with any other network block. Multiple CIDR ranges may be specified.	An IP address allocation in CIDR format. The default value is `10.0.0.0/16`.

1.2.9. Modifying advanced network configuration parameters

You can modify the advanced network configuration parameters only before you install the cluster. Advanced configuration customization lets you integrate your cluster into your existing network environment by specifying an MTU or VXLAN port, by allowing customization of kube-proxy settings, and by specifying a different mode for the openshiftSDNConfig parameter.

Important

Modifying the OpenShift Container Platform manifest files created by the installation program is not supported. Applying a manifest file that you create, as in the following procedure, is supported.

Prerequisites

Create the install-config.yaml file and complete any modifications to it.
Create the Ignition config files for your cluster.

Procedure

Use the following command to create manifests:
```
$ ./openshift-install create manifests --dir=<installation_directory> 1
```
1
For <installation_directory>, specify the name of the directory that contains the install-config.yaml file for your cluster.
Create a file that is named cluster-network-03-config.yml in the <installation_directory>/manifests/ directory:
```
$ touch <installation_directory>/manifests/cluster-network-03-config.yml 1
```
1
For <installation_directory>, specify the directory name that contains the manifests/ directory for your cluster.
After creating the file, several network configuration files are in the manifests/ directory, as shown:
```
$ ls <installation_directory>/manifests/cluster-network-*
```
Example output
```
cluster-network-01-crd.yml
cluster-network-02-config.yml
cluster-network-03-config.yml
```
Open the cluster-network-03-config.yml file in an editor and enter a CR that describes the Operator configuration you want:
```
apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec: 1
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  serviceNetwork:
  - 172.30.0.0/16
  defaultNetwork:
    type: OpenShiftSDN
    openshiftSDNConfig:
      mode: NetworkPolicy
      mtu: 1450
      vxlanPort: 4789
```
1
The parameters for the spec parameter are only an example. Specify your configuration for the Cluster Network Operator in the CR.
The CNO provides default values for the parameters in the CR, so you must specify only the parameters that you want to change.
Save the cluster-network-03-config.yml file and quit the text editor.
Optional: Back up the manifests/cluster-network-03-config.yml file. The installation program deletes the manifests/ directory when creating the cluster.

1.2.10. Cluster Network Operator configuration

The configuration for the cluster network is specified as part of the Cluster Network Operator (CNO) configuration and stored in a CR object that is named cluster. The CR specifies the parameters for the Network API in the operator.openshift.io API group.

You can specify the cluster network configuration for your OpenShift Container Platform cluster by setting the parameter values for the defaultNetwork parameter in the CNO CR. The following CR displays the default configuration for the CNO and explains both the parameters you can configure and the valid parameter values:

Cluster Network Operator CR

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  clusterNetwork: 1
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  serviceNetwork: 2
  - 172.30.0.0/16
  defaultNetwork: 3
    ...
  kubeProxyConfig: 4
    iptablesSyncPeriod: 30s 5
    proxyArguments:
      iptables-min-sync-period: 6
      - 0s

1 2: Specified in the install-config.yaml file.
3: Configures the default Container Network Interface (CNI) network provider for the cluster network.
4: The parameters for this object specify the kube-proxy configuration. If you do not specify the parameter values, the Cluster Network Operator applies the displayed default parameter values. If you are using the OVN-Kubernetes default CNI network provider, the kube-proxy configuration has no effect.
5: The refresh period for iptables rules. The default value is 30s. Valid suffixes include s, m, and h and are described in the Go time package documentation.
Note
Because of performance improvements introduced in OpenShift Container Platform 4.3 and greater, adjusting the iptablesSyncPeriod parameter is no longer necessary.
6: The minimum duration before refreshing iptables rules. This parameter ensures that the refresh does not happen too frequently. Valid suffixes include s, m, and h and are described in the Go time package.

1.2.10.1. Configuration parameters for the OpenShift SDN default CNI network provider

The following YAML object describes the configuration parameters for the OpenShift SDN default Container Network Interface (CNI) network provider.

defaultNetwork:
  type: OpenShiftSDN 1
  openshiftSDNConfig: 2
    mode: NetworkPolicy 3
    mtu: 1450 4
    vxlanPort: 4789 5

1

Specified in the install-config.yaml file.

2

Specify only if you want to override part of the OpenShift SDN configuration.

3

Configures the network isolation mode for OpenShift SDN. The allowed values are Multitenant, Subnet, or NetworkPolicy. The default value is NetworkPolicy.

4

The maximum transmission unit (MTU) for the VXLAN overlay network. This is detected automatically based on the MTU of the primary network interface. You do not normally need to override the detected MTU.

If the auto-detected value is not what you expected it to be, confirm that the MTU on the primary network interface on your nodes is correct. You cannot use this option to change the MTU value of the primary network interface on the nodes.

If your cluster requires different MTU values for different nodes, you must set this value to 50 less than the lowest MTU value in your cluster. For example, if some nodes in your cluster have an MTU of 9001, and some have an MTU of 1500, you must set this value to 1450.

5

The port to use for all VXLAN packets. The default value is 4789. If you are running in a virtualized environment with existing nodes that are part of another VXLAN network, then you might be required to change this. For example, when running an OpenShift SDN overlay on top of VMware NSX-T, you must select an alternate port for VXLAN, since both SDNs use the same default VXLAN port number.

On Amazon Web Services (AWS), you can select an alternate port for the VXLAN between port 9000 and port 9999.

1.2.10.2. Cluster Network Operator example configuration

A complete CR object for the CNO is displayed in the following example:

Cluster Network Operator example CR

apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  name: cluster
spec:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  serviceNetwork:
  - 172.30.0.0/16
  defaultNetwork:
    type: OpenShiftSDN
    openshiftSDNConfig:
      mode: NetworkPolicy
      mtu: 1450
      vxlanPort: 4789
  kubeProxyConfig:
    iptablesSyncPeriod: 30s
    proxyArguments:
      iptables-min-sync-period:
      - 0s

1.2.11. Creating the Ignition config files

Because you must manually start the cluster machines, you must generate the Ignition config files that the cluster needs to make its machines.

Important

Prerequisites

Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.

Procedure

Obtain the Ignition config files:
```
$ ./openshift-install create ignition-configs --dir=<installation_directory> 1
```
1
For <installation_directory>, specify the directory name to store the files that the installation program creates.
Important
If you created an install-config.yaml file, specify the directory that contains it. Otherwise, specify an empty directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.
The following files are generated in the directory:
```
.
├── auth
│   ├── kubeadmin-password
│   └── kubeconfig
├── bootstrap.ign
├── master.ign
├── metadata.json
└── worker.ign
```

1.2.12. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

1.2.12.1. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines using an ISO image

Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use an ISO image to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Have access to an HTTP server that you can access from your computer and that the machines that you create can access.

Procedure

Upload the control plane, compute, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use ISO images for this procedure. RHCOS qcow2 images are not supported for bare metal installs.
You must download the ISO file and the RAW disk file. Those file names resemble the following examples:
- ISO: rhcos-<version>-installer.<architecture>.iso
- Compressed metal RAW: rhcos-<version>-metal.<architecture>.raw.gz
Upload either the RAW RHCOS image file to your HTTP server and note its URL.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Use the ISO to start the RHCOS installation. Use one of the following installation options:
- Burn the ISO image to a disk and boot it directly.
- Use ISO redirection via a LOM interface.
After the instance boots, press the TAB or E key to edit the kernel command line.
Add the parameters to the kernel command line:
```
coreos.inst=yes
coreos.inst.install_dev=sda 1
coreos.inst.image_url=<image_URL> 2
coreos.inst.ignition_url=http://example.com/config.ign 3
ip=<dhcp or static IP address> 4 5
bond=<bonded_interface> 6
```
1
Specify the block device of the system to install to.
2
Specify the URL of the RAW image that you uploaded to your server.
3
Specify the URL of the Ignition config file for this machine type.
4
Set ip=dhcp or set an individual static IP address (ip=) and DNS server (nameserver=) on each node. See Configure advanced networking for details.
5
If you use multiple network interfaces or DNS servers, see Configure advanced networking for details on how to configure them.
6
Optionally, you can bond multiple network interfaces to a single interface using the bond= option, as described in Configure advanced networking.
Press Enter to complete the installation. After RHCOS installs, the system reboots. After the system reboots, it applies the Ignition config file that you specified.
Continue to create the machines for your cluster.
Important
You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

1.2.12.1.1. Configure advanced networking

Table 1.21. Configure advanced networking
Description	Examples
To configure an IP address, either use DHCP (`ip=dhcp`) or set an individual static IP address (`ip=<host_ip>`). Then identify the DNS server IP address (`nameserver=<dns_ip>`) on each node. This example sets: The node’s IP address to `10.10.10.2` The gateway address to `10.10.10.254` The netmask to `255.255.255.0` The hostname to `core0.example.com` The DNS server address to `4.4.4.41`	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none nameserver=4.4.4.41
Specify multiple network interfaces by specifying multiple `ip=` entries.	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can combine DHCP and static IP configurations on systems with multiple network interfaces.	ip=enp1s0:dhcp ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can provide multiple DNS servers by adding a `nameserver=` entry for each server.	nameserver=1.1.1.1 nameserver=8.8.8.8
Bonding multiple network interfaces to a single interface is optionally supported using the `bond=` option. In these two examples: The syntax for configuring a bonded interface is: `bond=name[:network_interfaces][:options]` name is the bonding device name (`bond0`), network_interfaces represents a comma-separated list of physical (ethernet) interfaces (`em1,em2`), and options is a comma-separated list of bonding options. (Enter `modinfo bonding` to see available options.) When you create a bonded interface using `bond=`, you must specify how the IP address is assigned and other information for the bonded interface.	To configure the bonded interface to use DHCP, set the bond’s IP address to `dhcp`. For example: bond=bond0:em1,em2:mode=active-backup ip=bond0:dhcp To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: bond=bond0:em1,em2:mode=active-backup ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none Important When using the advanced networking options, you could encounter issues during the first boot of RHCOS where the statically configured address is not present or not activated properly. In such cases, you might need to manually reboot the RHCOS machine to workaround this problem. In newer versions of RHCOS, this issue is resolved. See BZ#1902584 for additional details.

1.2.12.2. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines by PXE or iPXE booting

Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use PXE or iPXE booting to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Familiarity configuring the necessary DHCP, TFTP, and HTTP services for providing PXE or iPXE infrastructure.
Have access to an HTTP server and TFTP server that you can access from your computer.

Procedure

Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Obtain the compressed metal RAW image, kernel and initramfs files from the Product Downloads page on the Red Hat customer portal or the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use RAW images for this procedure. RHCOS qcow2 images are not supported for bare metal installs.
The file names contain the OpenShift Container Platform version number. They resemble the following examples:
- Compressed metal RAW image: rhcos-<version>-<architecture>-metal.<architecture>.raw.gz
- kernel: rhcos-<version>-<architecture>-installer-kernel-<architecture>
- initramfs: rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img
Upload the RAW image to your HTTP server.
Upload the additional files that are required for your booting method:
- For traditional PXE, upload the kernel and initramfs files to your TFTP server.
- For iPXE, upload the kernel and initramfs files to your HTTP server.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
Configure PXE or iPXE installation for the RHCOS images.
Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:
- For PXE:
```
DEFAULT pxeboot
TIMEOUT 20
PROMPT 0
LABEL pxeboot
    KERNEL rhcos-<version>-<architecture>-installer-kernel-<architecture> 1
    APPEND ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 2 3
```
  1
  Specify the location of the kernel file available on your TFTP server.
  2
  If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
  3
  Specify locations of the RHCOS files that you uploaded to your HTTP or TFTP server. The initrd parameter value is the location of the initramfs file on your TFTP server. The coreos.inst.image_url parameter value is the location of the compressed metal RAW image on your HTTP server, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file on your HTTP server.
  Note
  This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the APPEND line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux?.
- For iPXE:
```
kernel  http://<HTTP_server>/rhcos-<version>-<architecture>-installer-kernel-<architecture> ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
initrd http://<HTTP_server>/rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img 3
boot
```
  1
  Specify locations of the RHCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd parameter value references the name of the initramfs file that is supplied on the following initrd line, the coreos.inst.image_url parameter value is the location of the compressed metal RAW image, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.
  2
  If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
  3
  Specify the location of the initramfs file that you uploaded to your HTTP server.
  Note
  This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the kernel line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux?.
If you use UEFI, perform the following actions:
1. Provide the EFI binaries and grub.cfg file that are required for booting the system. You need the shim.efi binary and the grubx64.efi binary.
  - Extract the necessary EFI binaries by mounting the RHCOS ISO on your host and then mounting the images/efiboot.img file to your host. From the efiboot.img mount point, you then copy the EFI/redhat/shimx64.efi and EFI/redhat/grubx64.efi files to your TFTP server.
    # mkdir -p /mnt/{iso,efiboot} # mount -o loop rhcos-installer.x86_64.iso /mnt/iso # mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot # cp /mnt/efiboot/EFI/redhat/{shimx64.efi,grubx64.efi} . # umount /mnt/{efiboot,iso}
2. Copy the EFI/redhat/grub.cfg file that is included in the RHCOS ISO to your TFTP server.
3. Edit the grub.cfg file to include the following arguments:
```
menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os {
	linux rhcos-<version>-<architecture>-installer-kernel-<architecture> nomodeset rd.neednet=1 coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1
	initrd rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img 2
}
```
  1
  The first argument to the linux line item is the location of the kernel file that you uploaded to your TFTP server. For the coreos.inst.image_url parameter value, specify the location of the compressed metal RAW image that you uploaded to your HTTP server. For the coreos.inst.ignition_url paramter, specify the location of the bootstrap Ignition config file that you uploaded to your HTTP server.
  2
  Specify the location of the initramfs file that you uploaded to your TFTP server.
Continue to create the machines for your cluster.
Important
You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

1.2.13. Creating the cluster

Prerequisites

Create the required infrastructure for the cluster.
You obtained the installation program and generated the Ignition config files for your cluster.
You used the Ignition config files to create RHCOS machines for your cluster.
Your machines have direct Internet access or have an HTTP or HTTPS proxy available.

Procedure

Monitor the bootstrap process:
```
$ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ 1
    --log-level=info 2
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
2
To view different installation details, specify warn, debug, or error instead of info.
Example output
```
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.18.3 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources
```
The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.
After bootstrap process is complete, remove the bootstrap machine from the load balancer.
Important
You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the machine itself.

1.2.14. Logging in to the cluster

Prerequisites

Deploy an OpenShift Container Platform cluster.
Install the oc CLI.

Procedure

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

1.2.15. Approving the certificate signing requests for your machines

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.18.3
master-1  Ready     master  63m  v1.18.3
master-2  Ready     master  64m  v1.18.3
worker-0  NotReady  worker  76s  v1.18.3
worker-1  NotReady  worker  70s  v1.18.3

The output lists all of the machines that you created.

Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
...

In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:
Note
Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. Once the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
```

Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
...

If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
```

After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

Note

It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

For more information on CSRs, see Certificate Signing Requests.

1.2.16. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

Your control plane has initialized.

Procedure

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                 VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                       4.5.4     True        False         False      69s
cloud-credential                     4.5.4     True        False         False      12m
cluster-autoscaler                   4.5.4     True        False         False      11m
console                              4.5.4     True        False         False      46s
dns                                  4.5.4     True        False         False      11m
image-registry                       4.5.4     True        False         False      5m26s
ingress                              4.5.4     True        False         False      5m36s
kube-apiserver                       4.5.4     True        False         False      8m53s
kube-controller-manager              4.5.4     True        False         False      7m24s
kube-scheduler                       4.5.4     True        False         False      12m
machine-api                          4.5.4     True        False         False      12m
machine-config                       4.5.4     True        False         False      7m36s
marketplace                          4.5.4     True        False         False      7m54m
monitoring                           4.5.4     True        False         False      7h54s
network                              4.5.4     True        False         False      5m9s
node-tuning                          4.5.4     True        False         False      11m
openshift-apiserver                  4.5.4     True        False         False      11m
openshift-controller-manager         4.5.4     True        False         False      5m943s
openshift-samples                    4.5.4     True        False         False      3m55s
operator-lifecycle-manager           4.5.4     True        False         False      11m
operator-lifecycle-manager-catalog   4.5.4     True        False         False      11m
service-ca                           4.5.4     True        False         False      11m
service-catalog-apiserver            4.5.4     True        False         False      5m26s
service-catalog-controller-manager   4.5.4     True        False         False      5m25s
storage                              4.5.4     True        False         False      5m30s

Configure the Operators that are not available.

1.2.16.1. Image registry removed during installation

After installation, you must edit the Image Registry Operator configuration to switch the managementState from Removed to Managed.

Note

The Prometheus console provides an ImageRegistryRemoved alert, for example:

1.2.16.2. Image registry storage configuration

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

1.2.16.3. Configuring block registry storage for bare metal

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Important

Procedure

To set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy and runs with only one (1) replica:
```
$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
```
Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.
Edit the registry configuration so that it references the correct PVC.

1.2.17. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

Your control plane has initialized.
You have completed the initial Operator configuration.

Procedure

Confirm that all the cluster components are online with the following command:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.5.4     True        False         False      7m56s
cloud-credential                           4.5.4     True        False         False      31m
cluster-autoscaler                         4.5.4     True        False         False      16m
console                                    4.5.4     True        False         False      10m
csi-snapshot-controller                    4.5.4     True        False         False      16m
dns                                        4.5.4     True        False         False      22m
etcd                                       4.5.4     False       False         False      25s
image-registry                             4.5.4     True        False         False      16m
ingress                                    4.5.4     True        False         False      16m
insights                                   4.5.4     True        False         False      17m
kube-apiserver                             4.5.4     True        False         False      19m
kube-controller-manager                    4.5.4     True        False         False      20m
kube-scheduler                             4.5.4     True        False         False      20m
kube-storage-version-migrator              4.5.4     True        False         False      16m
machine-api                                4.5.4     True        False         False      22m
machine-config                             4.5.4     True        False         False      22m
marketplace                                4.5.4     True        False         False      16m
monitoring                                 4.5.4     True        False         False      10m
network                                    4.5.4     True        False         False      23m
node-tuning                                4.5.4     True        False         False      23m
openshift-apiserver                        4.5.4     True        False         False      17m
openshift-controller-manager               4.5.4     True        False         False      15m
openshift-samples                          4.5.4     True        False         False      16m
operator-lifecycle-manager                 4.5.4     True        False         False      22m
operator-lifecycle-manager-catalog         4.5.4     True        False         False      22m
operator-lifecycle-manager-packageserver   4.5.4     True        False         False      18m
service-ca                                 4.5.4     True        False         False      23m
service-catalog-apiserver                  4.5.4     True        False         False      23m
service-catalog-controller-manager         4.5.4     True        False         False      23m
storage                                    4.5.4     True        False         False      17m

Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

$ ./openshift-install --dir=<installation_directory> wait-for install-complete 1

1: For <installation_directory>, specify the path to the directory that you stored the installation files in.

Example output

INFO Waiting up to 30m0s for the cluster to initialize...

The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

Important

Confirm that the Kubernetes API server is communicating with the pods.

To view a list of all pods, use the following command:

$ oc get pods --all-namespaces

Example output

NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
...

View the logs for a pod that is listed in the output of the previous command by using the following command:
```
$ oc logs <pod_name> -n <namespace> 1
```
1
Specify the pod name and namespace, as shown in the output of the previous command.
If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

1.2.18. Next steps

Customize your cluster.
If necessary, you can opt out of remote health reporting.
Set up your registry and configure registry storage.

1.3. Installing a cluster on bare metal in a restricted network

In OpenShift Container Platform version 4.5, you can install a cluster on bare metal infrastructure that you provision in a restricted network.

Important

1.3.1. Prerequisites

Create a registry on your mirror host and obtain the imageContentSources data for your version of OpenShift Container Platform.
Important
Because the installation media is on the mirror host, you can use that computer to complete all installation steps.
Provision persistent storage for your cluster. To deploy a private image registry, your storage must provide ReadWriteMany access modes.
Review details about the OpenShift Container Platform installation and update processes.
If you use a firewall and plan to use telemetry, you must configure the firewall to allow the sites that your cluster requires access to.
Note
Be sure to also review this site list if you are configuring a proxy.

1.3.2. About installations in restricted networks

In OpenShift Container Platform 4.5, you can perform an installation that does not require an active connection to the Internet to obtain software components. Restricted network installations can be completed using installer-provisioned infrastructure or user-provisioned infrastructure, depending on the cloud platform to which you are installing the cluster.

If you choose to perform a restricted network installation on a cloud platform, you still require access to its cloud APIs. Some cloud functions, like Amazon Web Service’s IAM service, require Internet access, so you might still require Internet access. Depending on your network, you might require less Internet access for an installation on bare metal hardware or on VMware vSphere.

To complete a restricted network installation, you must create a registry that mirrors the contents of the OpenShift Container Platform registry and contains the installation media. You can create this registry on a mirror host, which can access both the Internet and your closed network, or by using other methods that meet your restrictions.

Important

Because of the complexity of the configuration for user-provisioned installations, consider completing a standard user-provisioned infrastructure installation before you attempt a restricted network installation using user-provisioned infrastructure. Completing this test installation might make it easier to isolate and troubleshoot any issues that might arise during your installation in a restricted network.

1.3.2.1. Additional limits

Clusters in restricted networks have the following additional limitations and restrictions:

The ClusterVersion status includes an Unable to retrieve available updates error.
By default, you cannot use the contents of the Developer Catalog because you cannot access the required image stream tags.

1.3.3. Internet and Telemetry access for OpenShift Container Platform

In OpenShift Container Platform 4.5, you require access to the Internet to obtain the images that are necessary to install your cluster. The Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, also requires Internet access. If your cluster is connected to the Internet, Telemetry runs automatically, and your cluster is registered to the Red Hat OpenShift Cluster Manager (OCM).

You must have Internet access to:

Access the Red Hat OpenShift Cluster Manager page to download the installation program and perform subscription management. If the cluster has Internet access and you do not disable Telemetry, that service automatically entitles your cluster.
Access Quay.io to obtain the packages that are required to install your cluster.
Obtain the packages that are required to perform cluster updates.

Important

1.3.4. Machine requirements for a cluster with user-provisioned infrastructure

For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.

1.3.4.1. Required machines

The smallest OpenShift Container Platform clusters require the following hosts:

One temporary bootstrap machine
Three control plane, or master, machines
At least two compute machines, which are also known as worker machines. If you are running a three-node cluster, running zero compute machines is supported. Running one compute machine is not supported.

Note

The cluster requires the bootstrap machine to deploy the OpenShift Container Platform cluster on the three control plane machines. You can remove the bootstrap machine after you install the cluster.

Important

To maintain high availability of your cluster, use separate physical hosts for these cluster machines.

The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system.

Note that RHCOS is based on Red Hat Enterprise Linux (RHEL) 8 and inherits all of its hardware certifications and requirements. See Red Hat Enterprise Linux technology capabilities and limits.

1.3.4.2. Network connectivity requirements

1.3.4.3. Minimum resource requirements

Each cluster machine must meet the following minimum requirements:

Machine	Operating System	vCPU ^[1]	Virtual RAM	Storage
Bootstrap	RHCOS	4	16 GB	120 GB
Control plane	RHCOS	4	16 GB	120 GB
Compute	RHCOS or RHEL 7.8 - 7.9	2	8 GB	120 GB

1 vCPU is equivalent to 1 physical core when simultaneous multithreading (SMT), or hyperthreading, is not enabled. When enabled, use the following formula to calculate the corresponding ratio: (threads per core × cores) × sockets = vCPUs.

1.3.4.4. Certificate signing requests management

1.3.5. Creating the user-provisioned infrastructure

Before you deploy an OpenShift Container Platform cluster that uses user-provisioned infrastructure, you must create the underlying infrastructure.

Prerequisites

Review the OpenShift Container Platform 4.x Tested Integrations page before you create the supporting infrastructure for your cluster.

Procedure

Configure DHCP or set static IP addresses on each node.
Provision the required load balancers.
Configure the ports for your machines.
Configure DNS.
Ensure network connectivity.

1.3.5.1. Networking requirements for user-provisioned infrastructure

All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require network in initramfs during boot to fetch Ignition config from the machine config server.

You must configure the network connectivity between machines to allow cluster components to communicate. Each machine must be able to resolve the host names of all other machines in the cluster.

Table 1.22. All machines to all machines
Protocol	Port	Description
ICMP	N/A	Network reachability tests
TCP	`1936`	Metrics
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101` and the Cluster Version Operator on port `9099`.
	`10250`-`10259`	The default ports that Kubernetes reserves
	`10256`	openshift-sdn
UDP	`4789`	VXLAN and Geneve
	`6081`	VXLAN and Geneve
	`9000`-`9999`	Host level services, including the node exporter on ports `9100`-`9101`.
TCP/UDP	`30000`-`32767`	Kubernetes node port

Table 1.23. All machines to control plane
Protocol	Port	Description
TCP	`6443`	Kubernetes API

Table 1.24. Control plane machines to control plane machines
Protocol	Port	Description
TCP	`2379`-`2380`	etcd server and peer ports

Network topology requirements

The infrastructure that you provision for your cluster must meet the following network topology requirements.

Load balancers

Before you install OpenShift Container Platform, you must provision two load balancers that meet the following requirements:

API load balancer: Provides a common endpoint for users, both human and machine, to interact with and configure the platform. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the API routes.
A stateless load balancing algorithm. The options vary based on the load balancer implementation.

Note

Session persistence is not required for the API load balancer to function properly.

Configure the following ports on both the front and back of the load balancers:

Table 1.25. API load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`6443`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane. You must configure the `/readyz` endpoint for the API server health check probe.	X	X	Kubernetes API server
`22623`	Bootstrap and control plane. You remove the bootstrap machine from the load balancer after the bootstrap machine initializes the cluster control plane.	X		Machine config server

Note

Application Ingress load balancer: Provides an Ingress point for application traffic flowing in from outside the cluster. Configure the following conditions:

Layer 4 load balancing only. This can be referred to as Raw TCP, SSL Passthrough, or SSL Bridge mode. If you use SSL Bridge mode, you must enable Server Name Indication (SNI) for the Ingress routes.
A connection-based or session-based persistence is recommended, based on the options available and types of applications that will be hosted on the platform.

Configure the following ports on both the front and back of the load balancers:

Table 1.26. Application Ingress load balancer
Port	Back-end machines (pool members)	Internal	External	Description
`443`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTPS traffic
`80`	The machines that run the Ingress router pods, compute, or worker, by default.	X	X	HTTP traffic

Tip

If the true IP address of the client can be seen by the load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption.

Note

A working configuration for the Ingress router is required for an OpenShift Container Platform cluster. You must configure the Ingress router after the control plane initializes.

NTP configuration

If a DHCP server provides NTP server information, the chrony time service on the Red Hat Enterprise Linux CoreOS (RHCOS) machines read the information and can sync the clock with the NTP servers.

Additional resources

Configuring chrony time service

1.3.5.2. User-provisioned DNS requirements

Table 1.27. Required DNS records
Component	Record	Description
Kubernetes API	`api.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Kubernetes API	`api-int.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the load balancer for the control plane machines. These records must be resolvable from all the nodes within the cluster. Important The API server must be able to resolve the worker nodes by the host names that are recorded in Kubernetes. If the API server cannot resolve the node names, then proxied API calls can fail, and you cannot retrieve logs from pods.
Routes	`*.apps.<cluster_name>.<base_domain>.`	Add a wildcard DNS A/AAAA or CNAME record that refers to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster.
Bootstrap	`bootstrap.<cluster_name>.<base_domain>.`	Add a DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the bootstrap machine. These records must be resolvable by the nodes within the cluster.
Master hosts	`<master><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the master nodes. These records must be resolvable by the nodes within the cluster.
Worker hosts	`<worker><n>.<cluster_name>.<base_domain>.`	Add DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the worker nodes. These records must be resolvable by the nodes within the cluster.

Tip

You can use the nslookup <hostname> command to verify name resolution. You can use the dig -x <ip_address> command to verify reverse name resolution for the PTR records.

Example 1.5. Sample DNS zone database

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
	IN	MX 10	smtp.example.com.
;
;
ns1	IN	A	192.168.1.5
smtp	IN	A	192.168.1.5
;
helper	IN	A	192.168.1.5
helper.ocp4	IN	A	192.168.1.5
;
; The api identifies the IP of your load balancer.
api.ocp4		IN	A	192.168.1.5
api-int.ocp4		IN	A	192.168.1.5
;
; The wildcard also identifies the load balancer.
*.apps.ocp4		IN	A	192.168.1.5
;
; Create an entry for the bootstrap host.
bootstrap.ocp4	IN	A	192.168.1.96
;
; Create entries for the master hosts.
master0.ocp4		IN	A	192.168.1.97
master1.ocp4		IN	A	192.168.1.98
master2.ocp4		IN	A	192.168.1.99
;
; Create entries for the worker hosts.
worker0.ocp4		IN	A	192.168.1.11
worker1.ocp4		IN	A	192.168.1.7
;
;EOF

The following example BIND zone file shows sample PTR records for reverse name resolution.

Example 1.6. Sample DNS zone database for reverse records

$TTL 1W
@	IN	SOA	ns1.example.com.	root (
			2019070700	; serial
			3H		; refresh (3 hours)
			30M		; retry (30 minutes)
			2W		; expiry (2 weeks)
			1W )		; minimum (1 week)
	IN	NS	ns1.example.com.
;
; The syntax is "last octet" and the host must have an FQDN
; with a trailing dot.
97	IN	PTR	master0.ocp4.example.com.
98	IN	PTR	master1.ocp4.example.com.
99	IN	PTR	master2.ocp4.example.com.
;
96	IN	PTR	bootstrap.ocp4.example.com.
;
5	IN	PTR	api.ocp4.example.com.
5	IN	PTR	api-int.ocp4.example.com.
;
11	IN	PTR	worker0.ocp4.example.com.
7	IN	PTR	worker1.ocp4.example.com.
;
;EOF

1.3.6. Generating an SSH private key and adding it to the agent

Note

In a production environment, you require disaster recovery and debugging.

You can use this key to SSH into the master nodes as the user core. When you deploy the cluster, the key is added to the core user’s ~/.ssh/authorized_keys list.

Note

You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs.

Procedure

If you do not have an SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:
```
$ ssh-keygen -t ed25519 -N '' \
    -f <path>/<file_name> 1
```
1
Specify the path and file name, such as ~/.ssh/id_rsa, of the new SSH key. If you have an existing key pair, ensure your public key is in the your ~/.ssh directory.
Running this command generates an SSH key that does not require a password in the location that you specified.
Note
If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the x86_64 architecture, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.
Start the ssh-agent process as a background task:
```
$ eval "$(ssh-agent -s)"
```
Example output
```
Agent pid 31874
```

If your cluster is in FIPS mode, only use FIPS-compliant algorithms to generate the SSH key. The key must be either RSA or ECDSA.

Add your SSH private key to the ssh-agent:
```
$ ssh-add <path>/<file_name> 1
```
Example output
```
Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
```
1
Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa

Next steps

When you install OpenShift Container Platform, provide the SSH public key to the installation program. If you install a cluster on infrastructure that you provision, you must provide this key to your cluster’s machines.

1.3.7. Manually creating the installation configuration file

For installations of OpenShift Container Platform that use user-provisioned infrastructure, you manually generate your installation configuration file.

Prerequisites

Obtain the OpenShift Container Platform installation program and the access token for your cluster.
Obtain the imageContentSources section from the output of the command to mirror the repository.
Obtain the contents of the certificate for your mirror registry.

Procedure

Create an installation directory to store your required installation assets in:
```
$ mkdir <installation_directory>
```
Important
You must create a directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OpenShift Container Platform version.
Customize the following install-config.yaml file template and save it in the <installation_directory>.
Note
You must name this configuration file install-config.yaml.
- Unless you use a registry that RHCOS trusts by default, such as docker.io, you must provide the contents of the certificate for your mirror repository in the additionalTrustBundle section. In most cases, you must provide the certificate for your mirror.
- You must include the imageContentSources section from the output of the command to mirror the repository.
Back up the install-config.yaml file so that you can use it to install multiple clusters.
Important
The install-config.yaml file is consumed during the next step of the installation process. You must back it up now.

1.3.7.1. Installation configuration parameters

Note

After installation, you cannot modify these parameters in the install-config.yaml file.

Important

1.3.7.1.1. Required configuration parameters

Required installation configuration parameters are described in the following table:

Table 1.28. Required parameters
Parameter	Description	Values
`apiVersion`	The API version for the `install-config.yaml` content. The current version is `v1`. The installer may also support older API versions.	String
`baseDomain`	The base domain of your cloud provider. The base domain is used to create routes to your OpenShift Container Platform cluster components. The full DNS name for your cluster is a combination of the `baseDomain` and `metadata.name` parameter values that uses the `<metadata.name>.<baseDomain>` format.	A fully-qualified domain or subdomain name, such as `example.com`.
`metadata`	Kubernetes resource `ObjectMeta`, from which only the `name` parameter is consumed.	Object
`metadata.name`	The name of the cluster. DNS records for the cluster are all subdomains of `{{.metadata.name}}.{{.baseDomain}}`.	String of lowercase letters, hyphens (`-`), and periods (`.`), such as `dev`.
`platform`	The configuration for the specific platform upon which to perform the installation: `aws`, `baremetal`, `azure`, `openstack`, `ovirt`, `vsphere`. For additional information about `platform.<platform>` parameters, consult the following table for your specific platform.	Object
`pullSecret`	Get a pull secret from https://cloud.redhat.com/openshift/install/pull-secret to authenticate downloading container images for OpenShift Container Platform components from services such as Quay.io.	{ "auths":{ "cloud.openshift.com":{ "auth":"b3Blb=", "email":"you@example.com" }, "quay.io":{ "auth":"b3Blb=", "email":"you@example.com" } } }

1.3.7.1.2. Network configuration parameters

Only IPv4 addresses are supported.

Table 1.29. Network parameters
Parameter	Description	Values
`networking`	The configuration for the cluster network.	Object Note You cannot modify parameters specified by the `networking` object after installation.
`networking.networkType`	The cluster network provider Container Network Interface (CNI) plug-in to install.	Either `OpenShiftSDN` or `OVNKubernetes`. The default value is `OpenShiftSDN`.
`networking.clusterNetwork`	The IP address blocks for pods. The default value is `10.128.0.0/14` with a host prefix of `/23`. If you specify multiple IP address blocks, the blocks must not overlap.	An array of objects. For example: networking: clusterNetwork: - cidr: 10.128.0.0/14 hostPrefix: 23
`networking.clusterNetwork.cidr`	Required if you use `networking.clusterNetwork`. An IP address block. An IPv4 network.	An IP address block in Classless Inter-Domain Routing (CIDR) notation. The prefix length for an IPv4 block is between `0` and `32`.
`networking.clusterNetwork.hostPrefix`	The subnet prefix length to assign to each individual node. For example, if `hostPrefix` is set to `23` then each node is assigned a `/23` subnet out of the given `cidr`. A `hostPrefix` value of `23` provides 510 (2^(32 - 23) - 2) pod IP addresses.	A subnet prefix. The default value is `23`.
`networking.serviceNetwork`	The IP address block for services. The default value is `172.30.0.0/16`. The OpenShift SDN and OVN-Kubernetes network providers support only a single IP address block for the service network.	An array with an IP address block in CIDR format. For example: networking: serviceNetwork: - 172.30.0.0/16
`networking.machineNetwork`	The IP address blocks for machines. If you specify multiple IP address blocks, the blocks must not overlap.	An array of objects. For example: networking: machineNetwork: - cidr: 10.0.0.0/16
`networking.machineNetwork.cidr`	Required if you use `networking.machineNetwork`. An IP address block. The default value is `10.0.0.0/16` for all platforms other than libvirt. For libvirt, the default value is `192.168.126.0/24`.	An IP network block in CIDR notation. For example, `10.0.0.0/16`. Note Set the `networking.machineNetwork` to match the CIDR that the preferred NIC resides in.

1.3.7.1.3. Optional configuration parameters

Optional installation configuration parameters are described in the following table:

Table 1.30. Optional parameters
Parameter	Description	Values
`additionalTrustBundle`	A PEM-encoded X.509 certificate bundle that is added to the nodes' trusted certificate store. This trust bundle may also be used when a proxy has been configured.	String
`compute`	The configuration for the machines that comprise the compute nodes.	Array of machine-pool objects. For details, see the following "Machine-pool" table.
`compute.architecture`	Determines the instruction set architecture of the machines in the pool. Currently, heteregeneous clusters are not supported, so all pools must specify the same architecture. Valid values are `amd64` (the default).	String
`compute.hyperthreading`	Whether to enable or disable simultaneous multithreading, or `hyperthreading`, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.	`Enabled` or `Disabled`
`compute.name`	Required if you use `compute`. The name of the machine pool.	`worker`
`compute.platform`	Required if you use `compute`. Use this parameter to specify the cloud provider to host the worker machines. This parameter value must match the `controlPlane.platform` parameter value.	`aws`, `azure`, `gcp`, `openstack`, `ovirt`, `vsphere`, or `{}`
`compute.replicas`	The number of compute machines, which are also known as worker machines, to provision.	A positive integer greater than or equal to `2`. The default value is `3`.
`controlPlane`	The configuration for the machines that comprise the control plane.	Array of `MachinePool` objects. For details, see the following "Machine-pool" table.
`controlPlane.architecture`	Determines the instruction set architecture of the machines in the pool. Currently, heterogeneous clusters are not supported, so all pools must specify the same architecture. Valid values are `amd64` (the default).	String
`controlPlane.hyperthreading`	Whether to enable or disable simultaneous multithreading, or `hyperthreading`, on control plane machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. Important If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.	`Enabled` or `Disabled`
`controlPlane.name`	Required if you use `controlPlane`. The name of the machine pool.	`master`
`controlPlane.platform`	Required if you use `controlPlane`. Use this parameter to specify the cloud provider that hosts the control plane machines. This parameter value must match the `compute.platform` parameter value.	`aws`, `azure`, `gcp`, `openstack`, `ovirt`, `vsphere`, or `{}`
`controlPlane.replicas`	The number of control plane machines to provision.	The only supported value is `3`, which is the default value.
`fips`	Enable or disable FIPS mode. The default is `false` (disabled). If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead. Note If you are using Azure File storage, you cannot enable FIPS mode.	`false` or `true`
`imageContentSources`	Sources and repositories for the release-image content.	Array of objects. Includes a `source` and, optionally, `mirrors`, as described in the following rows of this table.
`imageContentSources.source`	Required if you use `imageContentSources`. Specify the repository that users refer to, for example, in image pull specifications.	String
`imageContentSources.mirrors`	Specify one or more repositories that may also contain the same images.	Array of strings
`publish`	How to publish or expose the user-facing endpoints of your cluster, such as the Kubernetes API, OpenShift routes.	`Internal` or `External`. The default value is `External`. Setting this field to `Internal` is not supported on non-cloud platforms. Important If the value of the field is set to `Internal`, the cluster will become non-functional. For more information, refer to BZ#1953035.
`sshKey`	The SSH key to authenticate access to your cluster machines. Note For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your `ssh-agent` process uses.	For example, `sshKey: ssh-ed25519 AAAA..`.

1.3.7.2. Sample `install-config.yaml` file for bare metal

You can customize the install-config.yaml file to specify more details about your OpenShift Container Platform cluster’s platform or modify the values of the required parameters.

apiVersion: v1
baseDomain: example.com 1
compute: 2
- hyperthreading: Enabled 3
  name: worker
  replicas: 0 4
controlPlane: 5
  hyperthreading: Enabled 6
  name: master
  replicas: 3 7
metadata:
  name: test 8
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14 9
    hostPrefix: 23 10
  networkType: OpenShiftSDN
  serviceNetwork: 11
  - 172.30.0.0/16
platform:
  none: {} 12
fips: false 13
pullSecret: '{"auths":{"<local_registry>": {"auth": "<credentials>","email": "you@example.com"}}}' 14
sshKey: 'ssh-ed25519 AAAA...' 15
additionalTrustBundle: | 16
  -----BEGIN CERTIFICATE-----
  ZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZZ
  -----END CERTIFICATE-----
imageContentSources: 17
- mirrors:
  - <local_registry>/<local_repository_name>/release
  source: quay.io/openshift-release-dev/ocp-release
- mirrors:
  - <local_registry>/<local_repository_name>/release
  source: registry.svc.ci.openshift.org/ocp/release

1: The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
2 5: The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Although both sections currently define a single machine pool, it is possible that future versions of OpenShift Container Platform will support defining multiple compute pools during installation. Only one control plane pool is used.
3 6: Whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.
Note
Simultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreading parameter has no effect.
Important
If you disable hyperthreading, whether in the BIOS or in the install-config.yaml, ensure that your capacity planning accounts for the dramatically decreased machine performance.
4: You must set the value of the replicas parameter to 0. This parameter controls the number of workers that the cluster creates and manages for you, which are functions that the cluster does not perform when you use user-provisioned infrastructure. You must manually deploy worker machines for the cluster to use before you finish installing OpenShift Container Platform.
7: The number of control plane machines that you add to the cluster. Because the cluster uses this values as the number of etcd endpoints in the cluster, the value must match the number of control plane machines that you deploy.
8: The cluster name that you specified in your DNS records.
9: A block of IP addresses from which pod IP addresses are allocated. This block must not overlap with existing physical networks. These IP addresses are used for the pod network. If you need to access the pods from an external network, you must configure load balancers and routers to manage the traffic.
10: The subnet prefix length to assign to each individual node. For example, if hostPrefix is set to 23, then each node is assigned a /23 subnet out of the given cidr, which allows for 510 (2^(32 - 23) - 2) pod IPs addresses. If you are required to provide access to nodes from an external network, configure load balancers and routers to manage the traffic.
11: The IP address pool to use for service IP addresses. You can enter only one IP address pool. If you need to access the services from an external network, configure load balancers and routers to manage the traffic.
12: You must set the platform to none. You cannot provide additional platform configuration variables for bare metal infrastructure.
13: Whether to enable or disable FIPS mode. By default, FIPS mode is not enabled. If FIPS mode is enabled, the Red Hat Enterprise Linux CoreOS (RHCOS) machines that OpenShift Container Platform runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
14: For <local_registry>, specify the registry domain name, and optionally the port, that your mirror registry uses to serve content. For example registry.example.com or registry.example.com:5000. For <credentials>, specify the base64-encoded user name and password for your mirror registry.
15: The public portion of the default SSH key for the core user in Red Hat Enterprise Linux CoreOS (RHCOS).
Note
For production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agent process uses.
16: Provide the contents of the certificate file that you used for your mirror registry.
17: Provide the imageContentSources section from the output of the command to mirror the repository.

1.3.7.3. Configuring the cluster-wide proxy during installation

Note

Prerequisites

An existing install-config.yaml file.
Review the sites that your cluster requires access to and determine whether any need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. Add sites to the Proxy object’s spec.noProxy field to bypass the proxy if necessary.
Note
The Proxy object status.noProxy field is populated with the values of the networking.machineNetwork[].cidr, networking.clusterNetwork[].cidr, and networking.serviceNetwork[] fields from your installation configuration.
For installations on Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Red Hat OpenStack Platform (RHOSP), the Proxy object status.noProxy field is also populated with the instance metadata endpoint (169.254.169.254).

Procedure

Edit your install-config.yaml file and add the proxy settings. For example:
```
apiVersion: v1
baseDomain: my.domain.com
proxy:
  httpProxy: http://<username>:<pswd>@<ip>:<port> 1
  httpsProxy: http://<username>:<pswd>@<ip>:<port> 2
  noProxy: example.com 3
additionalTrustBundle: | 4
    -----BEGIN CERTIFICATE-----
    <MY_TRUSTED_CA_CERT>
    -----END CERTIFICATE-----
...
```
1
A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must be http. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpProxy value.
2
A proxy URL to use for creating HTTPS connections outside the cluster. If this field is not specified, then httpProxy is used for both HTTP and HTTPS connections. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must not specify an httpsProxy value.
3
A comma-separated list of destination domain names, domains, IP addresses, or other network CIDRs to exclude proxying. Preface a domain with . to match subdomains only. For example, .y.com matches x.y.com, but not y.com. Use * to bypass proxy for all destinations.
4
If provided, the installation program generates a config map that is named user-ca-bundle in the openshift-config namespace that contains one or more additional CA certificates that are required for proxying HTTPS connections. The Cluster Network Operator then creates a trusted-ca-bundle config map that merges these contents with the Red Hat Enterprise Linux CoreOS (RHCOS) trust bundle, and this config map is referenced in the Proxy object’s trustedCA field. The additionalTrustBundle field is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle. If you use an MITM transparent proxy network that does not require additional proxy configuration but requires additional CAs, you must provide the MITM CA certificate.
Note
The installation program does not support the proxy readinessEndpoints field.
Save the file and reference it when installing OpenShift Container Platform.

Note

Only the Proxy object named cluster is supported, and no additional proxies can be created.

1.3.8. Configuring a three-node cluster

Procedure

Edit the install-config.yaml file to set the number of compute replicas, which are also known as worker replicas, to 0, as shown in the following compute stanza:
```
compute:
- name: worker
  platform: {}
  replicas: 0
```

1.3.9. Creating the Kubernetes manifest and Ignition config files

Important

Prerequisites

Obtain the OpenShift Container Platform installation program. For a restricted network installation, these files are on your mirror host.
Create the install-config.yaml installation configuration file.

Procedure

Generate the Kubernetes manifests for the cluster:
```
$ ./openshift-install create manifests --dir=<installation_directory> 1
```
Example output
```
INFO Consuming Install Config from target directory
WARNING Making control-plane schedulable by setting MastersSchedulable to true for Scheduler cluster settings
```
1
For <installation_directory>, specify the installation directory that contains the install-config.yaml file you created.
Because you create your own compute machines later in the installation process, you can safely ignore this warning.

Warning

If you are running a three-node cluster, skip the following step to allow the masters to be schedulable.

Modify the <installation_directory>/manifests/cluster-scheduler-02-config.yml Kubernetes manifest file to prevent pods from being scheduled on the control plane machines:
1. Open the <installation_directory>/manifests/cluster-scheduler-02-config.yml file.
2. Locate the mastersSchedulable parameter and set its value to False.
3. Save and exit the file.

Obtain the Ignition config files:

$ ./openshift-install create ignition-configs --dir=<installation_directory> 1

1: For <installation_directory>, specify the same installation directory.

The following files are generated in the directory:

.
├── auth
│   ├── kubeadmin-password
│   └── kubeconfig
├── bootstrap.ign
├── master.ign
├── metadata.json
└── worker.ign

1.3.10. Configuring chrony time service

You must set the time server and related settings used by the chrony time service (chronyd) by modifying the contents of the chrony.conf file and passing those contents to your nodes as a machine config.

Procedure

Create the contents of the chrony.conf file and encode it as base64. For example:

$ cat << EOF | base64
    pool 0.rhel.pool.ntp.org iburst 1
    driftfile /var/lib/chrony/drift
    makestep 1.0 3
    rtcsync
    logdir /var/log/chrony
EOF

1: Specify any valid, reachable time source, such as the one provided by your DHCP server.

Example output

ICAgIHNlcnZlciBjbG9jay5yZWRoYXQuY29tIGlidXJzdAogICAgZHJpZnRmaWxlIC92YXIvbGli
L2Nocm9ueS9kcmlmdAogICAgbWFrZXN0ZXAgMS4wIDMKICAgIHJ0Y3N5bmMKICAgIGxvZ2RpciAv
dmFyL2xvZy9jaHJvbnkK

Create the MachineConfig object file, replacing the base64 string with the one you just created. This example adds the file to master nodes. You can change it to worker or make an additional MachineConfig for the worker role. Create MachineConfig files for each type of machine that your cluster uses:

$ cat << EOF > ./99-masters-chrony-configuration.yaml
apiVersion: machineconfiguration.openshift.io/v1
kind: MachineConfig
metadata:
  labels:
    machineconfiguration.openshift.io/role: master
  name: 99-masters-chrony-configuration
spec:
  config:
    ignition:
      config: {}
      security:
        tls: {}
      timeouts: {}
      version: 2.2.0
    networkd: {}
    passwd: {}
    storage:
      files:
      - contents:
          source: data:text/plain;charset=utf-8;base64,ICAgIHNlcnZlciBjbG9jay5yZWRoYXQuY29tIGlidXJzdAogICAgZHJpZnRmaWxlIC92YXIvbGliL2Nocm9ueS9kcmlmdAogICAgbWFrZXN0ZXAgMS4wIDMKICAgIHJ0Y3N5bmMKICAgIGxvZ2RpciAvdmFyL2xvZy9jaHJvbnkK
          verification: {}
        filesystem: root
        mode: 420
        path: /etc/chrony.conf
  osImageURL: ""
EOF

Make a backup copy of the configuration files.
Apply the configurations in one of two ways:
- If the cluster is not up yet, after you generate manifest files, add this file to the <installation_directory>/openshift directory, and then continue to create the cluster.
- If the cluster is already running, apply the file:
```
$ oc apply -f ./99-masters-chrony-configuration.yaml
```

1.3.11. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

1.3.11.1. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines using an ISO image

Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use an ISO image to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Have access to an HTTP server that you can access from your computer and that the machines that you create can access.

Procedure

Upload the control plane, compute, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use ISO images for this procedure. RHCOS qcow2 images are not supported for bare metal installs.
You must download the ISO file and the RAW disk file. Those file names resemble the following examples:
- ISO: rhcos-<version>-installer.<architecture>.iso
- Compressed metal RAW: rhcos-<version>-metal.<architecture>.raw.gz
Upload either the RAW RHCOS image file to your HTTP server and note its URL.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Use the ISO to start the RHCOS installation. Use one of the following installation options:
- Burn the ISO image to a disk and boot it directly.
- Use ISO redirection via a LOM interface.
After the instance boots, press the TAB or E key to edit the kernel command line.
Add the parameters to the kernel command line:
```
coreos.inst=yes
coreos.inst.install_dev=sda 1
coreos.inst.image_url=<image_URL> 2
coreos.inst.ignition_url=http://example.com/config.ign 3
ip=<dhcp or static IP address> 4 5
bond=<bonded_interface> 6
```
1
Specify the block device of the system to install to.
2
Specify the URL of the RAW image that you uploaded to your server.
3
Specify the URL of the Ignition config file for this machine type.
4
Set ip=dhcp or set an individual static IP address (ip=) and DNS server (nameserver=) on each node. See Configure advanced networking for details.
5
If you use multiple network interfaces or DNS servers, see Configure advanced networking for details on how to configure them.
6
Optionally, you can bond multiple network interfaces to a single interface using the bond= option, as described in Configure advanced networking.
Press Enter to complete the installation. After RHCOS installs, the system reboots. After the system reboots, it applies the Ignition config file that you specified.
Continue to create the machines for your cluster.
Important
You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

1.3.11.1.1. Configure advanced networking

Table 1.31. Configure advanced networking
Description	Examples
To configure an IP address, either use DHCP (`ip=dhcp`) or set an individual static IP address (`ip=<host_ip>`). Then identify the DNS server IP address (`nameserver=<dns_ip>`) on each node. This example sets: The node’s IP address to `10.10.10.2` The gateway address to `10.10.10.254` The netmask to `255.255.255.0` The hostname to `core0.example.com` The DNS server address to `4.4.4.41`	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none nameserver=4.4.4.41
Specify multiple network interfaces by specifying multiple `ip=` entries.	ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none ip=10.10.10.3::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can combine DHCP and static IP configurations on systems with multiple network interfaces.	ip=enp1s0:dhcp ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
You can provide multiple DNS servers by adding a `nameserver=` entry for each server.	nameserver=1.1.1.1 nameserver=8.8.8.8
Bonding multiple network interfaces to a single interface is optionally supported using the `bond=` option. In these two examples: The syntax for configuring a bonded interface is: `bond=name[:network_interfaces][:options]` name is the bonding device name (`bond0`), network_interfaces represents a comma-separated list of physical (ethernet) interfaces (`em1,em2`), and options is a comma-separated list of bonding options. (Enter `modinfo bonding` to see available options.) When you create a bonded interface using `bond=`, you must specify how the IP address is assigned and other information for the bonded interface.	To configure the bonded interface to use DHCP, set the bond’s IP address to `dhcp`. For example: bond=bond0:em1,em2:mode=active-backup ip=bond0:dhcp To configure the bonded interface to use a static IP address, enter the specific IP address you want and related information. For example: bond=bond0:em1,em2:mode=active-backup ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none Important When using the advanced networking options, you could encounter issues during the first boot of RHCOS where the statically configured address is not present or not activated properly. In such cases, you might need to manually reboot the RHCOS machine to workaround this problem. In newer versions of RHCOS, this issue is resolved. See BZ#1902584 for additional details.

1.3.11.2. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines by PXE or iPXE booting

Before you install a cluster on bare metal infrastructure that you provision, you must create RHCOS machines for it to use. You can use PXE or iPXE booting to create the machines.

Prerequisites

Obtain the Ignition config files for your cluster.
Familiarity configuring the necessary DHCP, TFTP, and HTTP services for providing PXE or iPXE infrastructure.
Have access to an HTTP server and TFTP server that you can access from your computer.

Procedure

Upload the master, worker, and bootstrap Ignition config files that the installation program created to your HTTP server. Note the URLs of these files.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Obtain the compressed metal RAW image, kernel and initramfs files from the Product Downloads page on the Red Hat customer portal or the RHCOS image mirror page.
Important
The RHCOS images might not change with every release of OpenShift Container Platform. You must download images with the highest version that is less than or equal to the OpenShift Container Platform version that you install. Use the image versions that match your OpenShift Container Platform version if they are available. Only use RAW images for this procedure. RHCOS qcow2 images are not supported for bare metal installs.
The file names contain the OpenShift Container Platform version number. They resemble the following examples:
- Compressed metal RAW image: rhcos-<version>-<architecture>-metal.<architecture>.raw.gz
- kernel: rhcos-<version>-<architecture>-installer-kernel-<architecture>
- initramfs: rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img
Upload the RAW image to your HTTP server.
Upload the additional files that are required for your booting method:
- For traditional PXE, upload the kernel and initramfs files to your TFTP server.
- For iPXE, upload the kernel and initramfs files to your HTTP server.
Important
If you plan to add more compute machines to your cluster after you finish installation, do not delete these files.
Configure the network boot infrastructure so that the machines boot from their local disks after RHCOS is installed on them.
Configure PXE or iPXE installation for the RHCOS images.
Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible:
- For PXE:
```
DEFAULT pxeboot
TIMEOUT 20
PROMPT 0
LABEL pxeboot
    KERNEL rhcos-<version>-<architecture>-installer-kernel-<architecture> 1
    APPEND ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 2 3
```
  1
  Specify the location of the kernel file available on your TFTP server.
  2
  If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
  3
  Specify locations of the RHCOS files that you uploaded to your HTTP or TFTP server. The initrd parameter value is the location of the initramfs file on your TFTP server. The coreos.inst.image_url parameter value is the location of the compressed metal RAW image on your HTTP server, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file on your HTTP server.
  Note
  This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the APPEND line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux?.
- For iPXE:
```
kernel  http://<HTTP_server>/rhcos-<version>-<architecture>-installer-kernel-<architecture> ip=dhcp rd.neednet=1 initrd=rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1 2
initrd http://<HTTP_server>/rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img 3
boot
```
  1
  Specify locations of the RHCOS files that you uploaded to your HTTP server. The kernel parameter value is the location of the kernel file, the initrd parameter value references the name of the initramfs file that is supplied on the following initrd line, the coreos.inst.image_url parameter value is the location of the compressed metal RAW image, and the coreos.inst.ignition_url parameter value is the location of the bootstrap Ignition config file.
  2
  If you use multiple NICs, specify a single interface in the ip option. For example, to use DHCP on a NIC that is named eno1, set ip=eno1:dhcp.
  3
  Specify the location of the initramfs file that you uploaded to your HTTP server.
  Note
  This configuration does not enable serial console access on machines with a graphical console. To configure a different console, add one or more console= arguments to the kernel line. For example, add console=tty0 console=ttyS0 to set the first PC serial port as the primary console and the graphical console as a secondary console. For more information, see How does one set up a serial terminal and/or console in Red Hat Enterprise Linux?.
If you use UEFI, perform the following actions:
1. Provide the EFI binaries and grub.cfg file that are required for booting the system. You need the shim.efi binary and the grubx64.efi binary.
  - Extract the necessary EFI binaries by mounting the RHCOS ISO on your host and then mounting the images/efiboot.img file to your host. From the efiboot.img mount point, you then copy the EFI/redhat/shimx64.efi and EFI/redhat/grubx64.efi files to your TFTP server.
    # mkdir -p /mnt/{iso,efiboot} # mount -o loop rhcos-installer.x86_64.iso /mnt/iso # mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot # cp /mnt/efiboot/EFI/redhat/{shimx64.efi,grubx64.efi} . # umount /mnt/{efiboot,iso}
2. Copy the EFI/redhat/grub.cfg file that is included in the RHCOS ISO to your TFTP server.
3. Edit the grub.cfg file to include the following arguments:
```
menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os {
	linux rhcos-<version>-<architecture>-installer-kernel-<architecture> nomodeset rd.neednet=1 coreos.inst=yes coreos.inst.install_dev=sda coreos.inst.image_url=http://<HTTP_server>/rhcos-<version>-<architecture>-metal.<architecture>.raw.gz coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign 1
	initrd rhcos-<version>-<architecture>-installer-initramfs.<architecture>.img 2
}
```
  1
  The first argument to the linux line item is the location of the kernel file that you uploaded to your TFTP server. For the coreos.inst.image_url parameter value, specify the location of the compressed metal RAW image that you uploaded to your HTTP server. For the coreos.inst.ignition_url paramter, specify the location of the bootstrap Ignition config file that you uploaded to your HTTP server.
  2
  Specify the location of the initramfs file that you uploaded to your TFTP server.
Continue to create the machines for your cluster.
Important
You must create the bootstrap and control plane machines at this time. If the control plane machines are not made schedulable, which is the default, also create at least two compute machines before you install the cluster.

1.3.12. Creating the cluster

Prerequisites

Create the required infrastructure for the cluster.
You obtained the installation program and generated the Ignition config files for your cluster.
You used the Ignition config files to create RHCOS machines for your cluster.

Procedure

Monitor the bootstrap process:
```
$ ./openshift-install --dir=<installation_directory> wait-for bootstrap-complete \ 1
    --log-level=info 2
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
2
To view different installation details, specify warn, debug, or error instead of info.
Example output
```
INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443...
INFO API v1.18.3 up
INFO Waiting up to 30m0s for bootstrapping to complete...
INFO It is now safe to remove the bootstrap resources
```
The command succeeds when the Kubernetes API server signals that it has been bootstrapped on the control plane machines.
After bootstrap process is complete, remove the bootstrap machine from the load balancer.
Important
You must remove the bootstrap machine from the load balancer at this point. You can also remove or reformat the machine itself.

1.3.13. Logging in to the cluster

Prerequisites

Deploy an OpenShift Container Platform cluster.
Install the oc CLI.

Procedure

Export the kubeadmin credentials:
```
$ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
```
1
For <installation_directory>, specify the path to the directory that you stored the installation files in.
Verify you can run oc commands successfully using the exported configuration:
```
$ oc whoami
```
Example output
```
system:admin
```

1.3.14. Approving the certificate signing requests for your machines

Prerequisites

You added machines to your cluster.

Procedure

Confirm that the cluster recognizes the machines:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  63m  v1.18.3
master-1  Ready     master  63m  v1.18.3
master-2  Ready     master  64m  v1.18.3
worker-0  NotReady  worker  76s  v1.18.3
worker-1  NotReady  worker  70s  v1.18.3

The output lists all of the machines that you created.

Review the pending CSRs and ensure that you see the client requests with the Pending or Approved status for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-8b2br   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
csr-8vnps   15m     system:serviceaccount:openshift-machine-config-operator:node-bootstrapper   Pending
...

In this example, two machines are joining the cluster. You might see more approved CSRs in the list.

If the CSRs were not approved, after all of the pending CSRs for the machines you added are in Pending status, approve the CSRs for your cluster machines:
Note
Because the CSRs rotate automatically, approve your CSRs within an hour of adding the machines to the cluster. If you do not approve them within an hour, the certificates will rotate, and more than two certificates will be present for each node. You must approve all of these certificates. Once the client CSR is approved, the Kubelet creates a secondary CSR for the serving certificate, which requires manual approval. Then, subsequent serving certificate renewal requests are automatically approved by the machine-approver if the Kubelet requests a new certificate with identical parameters.
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs --no-run-if-empty oc adm certificate approve
```

Now that your client requests are approved, you must review the server requests for each machine that you added to the cluster:

$ oc get csr

Example output

NAME        AGE     REQUESTOR                                                                   CONDITION
csr-bfd72   5m26s   system:node:ip-10-0-50-126.us-east-2.compute.internal                       Pending
csr-c57lv   5m26s   system:node:ip-10-0-95-157.us-east-2.compute.internal                       Pending
...

If the remaining CSRs are not approved, and are in the Pending status, approve the CSRs for your cluster machines:
- To approve them individually, run the following command for each valid CSR:
```
$ oc adm certificate approve <csr_name> 1
```
  1
  <csr_name> is the name of a CSR from the list of current CSRs.
- To approve all pending CSRs, run the following command:
```
$ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve
```

After all client and server CSRs have been approved, the machines have the Ready status. Verify this by running the following command:

$ oc get nodes

Example output

NAME      STATUS    ROLES   AGE  VERSION
master-0  Ready     master  73m  v1.20.0
master-1  Ready     master  73m  v1.20.0
master-2  Ready     master  74m  v1.20.0
worker-0  Ready     worker  11m  v1.20.0
worker-1  Ready     worker  11m  v1.20.0

Note

It can take a few minutes after approval of the server CSRs for the machines to transition to the Ready status.

Additional information

For more information on CSRs, see Certificate Signing Requests.

1.3.15. Initial Operator configuration

After the control plane initializes, you must immediately configure some Operators so that they all become available.

Prerequisites

Your control plane has initialized.

Procedure

Watch the cluster components come online:

$ watch -n5 oc get clusteroperators

Example output

NAME                                 VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                       4.5.4     True        False         False      69s
cloud-credential                     4.5.4     True        False         False      12m
cluster-autoscaler                   4.5.4     True        False         False      11m
console                              4.5.4     True        False         False      46s
dns                                  4.5.4     True        False         False      11m
image-registry                       4.5.4     True        False         False      5m26s
ingress                              4.5.4     True        False         False      5m36s
kube-apiserver                       4.5.4     True        False         False      8m53s
kube-controller-manager              4.5.4     True        False         False      7m24s
kube-scheduler                       4.5.4     True        False         False      12m
machine-api                          4.5.4     True        False         False      12m
machine-config                       4.5.4     True        False         False      7m36s
marketplace                          4.5.4     True        False         False      7m54m
monitoring                           4.5.4     True        False         False      7h54s
network                              4.5.4     True        False         False      5m9s
node-tuning                          4.5.4     True        False         False      11m
openshift-apiserver                  4.5.4     True        False         False      11m
openshift-controller-manager         4.5.4     True        False         False      5m943s
openshift-samples                    4.5.4     True        False         False      3m55s
operator-lifecycle-manager           4.5.4     True        False         False      11m
operator-lifecycle-manager-catalog   4.5.4     True        False         False      11m
service-ca                           4.5.4     True        False         False      11m
service-catalog-apiserver            4.5.4     True        False         False      5m26s
service-catalog-controller-manager   4.5.4     True        False         False      5m25s
storage                              4.5.4     True        False         False      5m30s

Configure the Operators that are not available.

1.3.15.1. Image registry storage configuration

Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate rollout strategy during upgrades.

1.3.15.1.1. Changing the image registry’s management state

To start the image registry, you must change the Image Registry Operator configuration’s managementState from Removed to Managed.

Procedure

Change managementState Image Registry Operator configuration from Removed to Managed. For example:

$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"managementState":"Managed"}}'

1.3.15.1.2. Configuring registry storage for bare metal

As a cluster administrator, following installation you must configure your registry to use storage.

Prerequisites

Cluster administrator permissions.
A cluster on bare metal.
Persistent storage provisioned for your cluster, such as Red Hat OpenShift Container Storage.
Important
OpenShift Container Platform supports ReadWriteOnce access for image registry storage when you have only one replica. To deploy an image registry that supports high availability with two or more replicas, ReadWriteMany access is required.
Must have 100Gi capacity.

Procedure

To configure your registry to use storage, change the spec.storage.pvc in the configs.imageregistry/cluster resource.
Note
When using shared storage, review your security settings to prevent outside access.
Verify that you do not have a registry pod:
```
$ oc get pod -n openshift-image-registry
```
Note
If the storage type is emptyDIR, the replica number cannot be greater than 1.
Check the registry configuration:
```
$ oc edit configs.imageregistry.operator.openshift.io
```
Example output
```
storage:
  pvc:
    claim:
```
Leave the claim field blank to allow the automatic creation of an image-registry-storage PVC.
Check the clusteroperator status:
```
$ oc get clusteroperator image-registry
```

1.3.15.1.3. Configuring storage for the image registry in non-production clusters

Procedure

To set the image registry storage to an empty directory:
```
$ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'
```
Warning
Configure this option for only non-production clusters.
If you run this command before the Image Registry Operator initializes its components, the oc patch command fails with the following error:
```
Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found
```
Wait a few minutes and run the command again.
Ensure that your registry is set to managed to enable building and pushing of images.
- Run:
```
$ oc edit configs.imageregistry/cluster
```
  Then, change the line
```
managementState: Removed
```
  to
```
managementState: Managed
```

1.3.15.1.4. Configuring block registry storage for bare metal

To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.

Important

Procedure

To set the image registry storage as a block storage type, patch the registry so that it uses the Recreate rollout strategy and runs with only one (1) replica:
```
$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
```
Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.
Edit the registry configuration so that it references the correct PVC.

1.3.16. Completing installation on user-provisioned infrastructure

After you complete the Operator configuration, you can finish installing the cluster on infrastructure that you provide.

Prerequisites

Your control plane has initialized.
You have completed the initial Operator configuration.

Procedure

Confirm that all the cluster components are online with the following command:

$ watch -n5 oc get clusteroperators

Example output

NAME                                       VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
authentication                             4.5.4     True        False         False      7m56s
cloud-credential                           4.5.4     True        False         False      31m
cluster-autoscaler                         4.5.4     True        False         False      16m
console                                    4.5.4     True        False         False      10m
csi-snapshot-controller                    4.5.4     True        False         False      16m
dns                                        4.5.4     True        False         False      22m
etcd                                       4.5.4     False       False         False      25s
image-registry                             4.5.4     True        False         False      16m
ingress                                    4.5.4     True        False         False      16m
insights                                   4.5.4     True        False         False      17m
kube-apiserver                             4.5.4     True        False         False      19m
kube-controller-manager                    4.5.4     True        False         False      20m
kube-scheduler                             4.5.4     True        False         False      20m
kube-storage-version-migrator              4.5.4     True        False         False      16m
machine-api                                4.5.4     True        False         False      22m
machine-config                             4.5.4     True        False         False      22m
marketplace                                4.5.4     True        False         False      16m
monitoring                                 4.5.4     True        False         False      10m
network                                    4.5.4     True        False         False      23m
node-tuning                                4.5.4     True        False         False      23m
openshift-apiserver                        4.5.4     True        False         False      17m
openshift-controller-manager               4.5.4     True        False         False      15m
openshift-samples                          4.5.4     True        False         False      16m
operator-lifecycle-manager                 4.5.4     True        False         False      22m
operator-lifecycle-manager-catalog         4.5.4     True        False         False      22m
operator-lifecycle-manager-packageserver   4.5.4     True        False         False      18m
service-ca                                 4.5.4     True        False         False      23m
service-catalog-apiserver                  4.5.4     True        False         False      23m
service-catalog-controller-manager         4.5.4     True        False         False      23m
storage                                    4.5.4     True        False         False      17m

Alternatively, the following command notifies you when all of the clusters are available. It also retrieves and displays credentials:

$ ./openshift-install --dir=<installation_directory> wait-for install-complete 1

1: For <installation_directory>, specify the path to the directory that you stored the installation files in.

Example output

INFO Waiting up to 30m0s for the cluster to initialize...

The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server.

Important

Confirm that the Kubernetes API server is communicating with the pods.

To view a list of all pods, use the following command:

$ oc get pods --all-namespaces

Example output

NAMESPACE                         NAME                                            READY   STATUS      RESTARTS   AGE
openshift-apiserver-operator      openshift-apiserver-operator-85cb746d55-zqhs8   1/1     Running     1          9m
openshift-apiserver               apiserver-67b9g                                 1/1     Running     0          3m
openshift-apiserver               apiserver-ljcmx                                 1/1     Running     0          1m
openshift-apiserver               apiserver-z25h4                                 1/1     Running     0          2m
openshift-authentication-operator authentication-operator-69d5d8bf84-vh2n8        1/1     Running     0          5m
...

View the logs for a pod that is listed in the output of the previous command by using the following command:
```
$ oc logs <pod_name> -n <namespace> 1
```
1
Specify the pod name and namespace, as shown in the output of the previous command.
If the pod logs display, the Kubernetes API server can communicate with the cluster machines.

1.3.17. Next steps

Customize your cluster.
Configure image streams for the Cluster Samples Operator and the must-gather tool.
Learn how to use Operator Lifecycle Manager (OLM) on restricted networks.
If the mirror registry that you used to install your cluster has a trusted CA, add it to the cluster by configuring additional trust stores.
If necessary, you can opt out of remote health reporting.

이 콘텐츠는 선택한 언어로 제공되지 않습니다.

Chapter 1. Installing on bare metal

1.1. Installing a cluster on bare metal

1.1.1. Prerequisites

1.1.2. Internet and Telemetry access for OpenShift Container Platform

1.1.3. Machine requirements for a cluster with user-provisioned infrastructure

1.1.3.1. Required machines

1.1.3.2. Network connectivity requirements

1.1.3.3. Minimum resource requirements

1.1.3.4. Certificate signing requests management

1.1.4. Creating the user-provisioned infrastructure

1.1.4.1. Networking requirements for user-provisioned infrastructure

Network topology requirements

Load balancers

NTP configuration

1.1.4.2. User-provisioned DNS requirements

1.1.5. Generating an SSH private key and adding it to the agent

1.1.6. Obtaining the installation program

1.1.7. Installing the CLI by downloading the binary

1.1.7.1. Installing the CLI on Linux

1.1.7.2. Installing the CLI on Windows

1.1.7.3. Installing the CLI on macOS

1.1.8. Manually creating the installation configuration file

1.1.8.1. Installation configuration parameters

1.1.8.1.1. Required configuration parameters

1.1.8.1.2. Network configuration parameters

1.1.8.1.3. Optional configuration parameters

1.1.8.2. Sample install-config.yaml file for bare metal

1.1.8.3. Configuring the cluster-wide proxy during installation

1.1.9. Configuring a three-node cluster

1.1.10. Creating the Kubernetes manifest and Ignition config files

1.1.11. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

1.1.11.1. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines using an ISO image

1.1.11.1.1. Configure advanced networking

1.1.11.2. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines by PXE or iPXE booting

1.1.12. Creating the cluster

1.1.13. Logging in to the cluster

1.1.14. Approving the certificate signing requests for your machines

1.1.15. Initial Operator configuration

1.1.15.1. Image registry removed during installation

1.1.15.2. Image registry storage configuration

1.1.15.2.1. Configuring registry storage for bare metal

1.1.15.2.2. Configuring storage for the image registry in non-production clusters

1.1.15.2.3. Configuring block registry storage for bare metal

1.1.16. Completing installation on user-provisioned infrastructure

1.1.17. Next steps

1.2. Installing a cluster on bare metal with network customizations

1.2.1. Prerequisites

1.2.2. Internet and Telemetry access for OpenShift Container Platform

1.2.3. Machine requirements for a cluster with user-provisioned infrastructure

1.2.3.1. Required machines

1.2.3.2. Network connectivity requirements

1.2.3.3. Minimum resource requirements

1.2.3.4. Certificate signing requests management

1.2.4. Creating the user-provisioned infrastructure

1.2.4.1. Networking requirements for user-provisioned infrastructure

Network topology requirements

Load balancers

NTP configuration

1.2.4.2. User-provisioned DNS requirements

1.2.5. Generating an SSH private key and adding it to the agent

1.2.6. Obtaining the installation program

1.2.7. Installing the CLI by downloading the binary

1.2.7.1. Installing the CLI on Linux

1.2.7.2. Installing the CLI on Windows

1.2.7.3. Installing the CLI on macOS

1.2.8. Manually creating the installation configuration file

1.2.8.1. Installation configuration parameters

1.2.8.1.1. Required configuration parameters

1.2.8.1.2. Network configuration parameters

1.2.8.1.3. Optional configuration parameters

1.2.8.2. Sample install-config.yaml file for bare metal

1.2.8.3. Network configuration parameters

1.2.9. Modifying advanced network configuration parameters

1.2.10. Cluster Network Operator configuration

1.2.10.1. Configuration parameters for the OpenShift SDN default CNI network provider

1.2.10.2. Cluster Network Operator example configuration

1.2.11. Creating the Ignition config files

1.2.12. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines

1.2.12.1. Creating Red Hat Enterprise Linux CoreOS (RHCOS) machines using an ISO image

1.1.8.2. Sample `install-config.yaml` file for bare metal

1.2.8.2. Sample `install-config.yaml` file for bare metal

1.3.7.2. Sample `install-config.yaml` file for bare metal