This documentation is for a release that is no longer maintained
See documentation for the latest supported version 3 or the latest supported version 4.Este contenido no está disponible en el idioma seleccionado.
Chapter 16. Installing on any platform
16.1. Installing a cluster on any platform
In OpenShift Container Platform version 4.8, you can install a cluster on any infrastructure that you provision, including virtualization and cloud environments.
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 virtualized or cloud environments.
16.1.1. Prerequisites
- You reviewed details about the OpenShift Container Platform installation and update processes.
- You read the documentation on selecting a cluster installation method and preparing it for users.
- If you use a firewall, you configured 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. 
16.1.2. Internet access for OpenShift Container Platform
In OpenShift Container Platform 4.8, you require access to the internet to install your cluster.
You must have internet access to:
- Access OpenShift Cluster Manager 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.
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.
16.1.3. Requirements for a cluster with user-provisioned infrastructure
For a cluster that contains user-provisioned infrastructure, you must deploy all of the required machines.
This section describes the requirements for deploying OpenShift Container Platform on user-provisioned infrastructure.
16.1.3.1. Required machines
The smallest OpenShift Container Platform clusters require the following hosts:
| Hosts | Description | 
|---|---|
| One temporary bootstrap machine | 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. | 
| Three control plane machines | The control plane machines run the Kubernetes and OpenShift Container Platform services that form the control plane. | 
| At least two compute machines, which are also known as worker machines. | The workloads requested by OpenShift Container Platform users run on the compute machines. | 
To improve high availability of your cluster, distribute the control plane machines over different z/VM instances on at least two physical machines.
The bootstrap and control plane machines must use Red Hat Enterprise Linux CoreOS (RHCOS) as the operating system. However, the compute machines can choose between Red Hat Enterprise Linux CoreOS (RHCOS) or Red Hat Enterprise Linux (RHEL) 7.9.
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.
16.1.3.2. Minimum resource requirements
Each cluster machine must meet the following minimum requirements:
| Machine | Operating System | vCPU [1] | Virtual RAM | Storage | IOPS | 
|---|---|---|---|---|---|
| Bootstrap | RHCOS | 4 | 16 GB | 100 GB | N/A | 
| Control plane | RHCOS | 4 | 16 GB | 100 GB | N/A | 
| Compute | RHCOS | 2 | 8 GB | 100 GB | N/A | 
- One physical core (IFL) provides two logical cores (threads) when SMT-2 is enabled. The hypervisor can provide two or more vCPUs.
16.1.3.3. 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.
					
16.1.3.4. Networking requirements for user-provisioned infrastructure
						All the Red Hat Enterprise Linux CoreOS (RHCOS) machines require networking to be configured in initramfs during boot to fetch their Ignition config files.
					
During the initial boot, the machines require an HTTP or HTTPS server to establish a network connection to download their Ignition config files.
The machines are configured with static IP addresses. No DHCP server is required. Ensure that the machines have persistent IP addresses and hostnames.
The Kubernetes API server 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.
16.1.3.4.1. Network connectivity requirements
You must configure the network connectivity between machines to allow OpenShift Container Platform cluster components to communicate. Each machine must be able to resolve the hostnames of all other machines in the cluster.
This section provides details about the ports that are required.
In connected OpenShift Container Platform environments, all nodes are required to have internet access to pull images for platform containers and provide telemetry data to Red Hat.
| Protocol | Port | Description | 
|---|---|---|
| ICMP | N/A | Network reachability tests | 
| TCP | 
											 | Metrics | 
| 
											 | 
											Host level services, including the node exporter on ports  | |
| 
											 | The default ports that Kubernetes reserves | |
| 
											 | openshift-sdn | |
| UDP | 
											 | VXLAN and Geneve | 
| 
											 | VXLAN and Geneve | |
| 
											 | 
											Host level services, including the node exporter on ports  | |
| 
											 | IPsec IKE packets | |
| 
											 | IPsec NAT-T packets | |
| TCP/UDP | 
											 | Kubernetes node port | 
| ESP | N/A | IPsec Encapsulating Security Payload (ESP) | 
| Protocol | Port | Description | 
|---|---|---|
| TCP | 
											 | Kubernetes API | 
| Protocol | Port | Description | 
|---|---|---|
| TCP | 
											 | etcd server and peer ports | 
NTP configuration for user-provisioned infrastructure
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.
16.1.3.5. User-provisioned DNS requirements
In OpenShift Container Platform deployments, DNS name resolution is required for the following components:
- The Kubernetes API
- The OpenShift Container Platform application wildcard
- The bootstrap, control plane, and compute machines
Reverse DNS resolution is also required for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines.
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 hostnames for all the nodes, unless the hostnames are provided by DHCP. 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 a user-provisioned OpenShift Container Platform cluster and they must be in place before installation. In each record, <cluster_name> is the cluster name and <base_domain> is the base domain that you specify in the install-config.yaml file. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>..
					
| Component | Record | Description | 
|---|---|---|
| Kubernetes API | 
										 | A DNS A/AAAA or CNAME record, and a DNS PTR record, to identify the API load balancer. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster. | 
| 
										 | A DNS A/AAAA or CNAME record, and a DNS PTR record, to internally identify the API load balancer. 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 hostnames 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 | 
										 | A wildcard DNS A/AAAA or CNAME record that refers to the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default. These records must be resolvable by both clients external to the cluster and from all the nodes within the cluster. 
										For example,  | 
| Bootstrap machine | 
										 | 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. | 
| Control plane machines | 
										 | DNS A/AAAA or CNAME records and DNS PTR records to identify each machine for the control plane nodes (also known as the master nodes). These records must be resolvable by the nodes within the cluster. | 
| Compute machines | 
										 | 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. | 
In OpenShift Container Platform 4.4 and later, you do not need to specify etcd host and SRV records in your DNS configuration.
						You can use the dig command to verify name and reverse name resolution. See the section on Validating DNS resolution for user-provisioned infrastructure for detailed validation steps.
					
16.1.3.5.1. Example DNS configuration for user-provisioned clusters
This section provides A and PTR record configuration samples that meet the DNS requirements for deploying OpenShift Container Platform on user-provisioned infrastructure. The samples are not meant to provide advice for choosing one DNS solution over another.
							In the examples, the cluster name is ocp4 and the base domain is example.com.
						
Example DNS A record configuration for a user-provisioned cluster
The following example is a BIND zone file that shows sample A records for name resolution in a user-provisioned cluster.
Example 16.1. Sample DNS zone database
- 1
- Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer.
- 2
- Provides name resolution for the Kubernetes API. The record refers to the IP address of the API load balancer and is used for internal cluster communications.
- 3
- Provides name resolution for the wildcard routes. The record refers to the IP address of the application ingress load balancer. The application ingress load balancer targets the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.NoteIn the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation. 
- 4
- Provides name resolution for the bootstrap machine.
- 5 6 7
- Provides name resolution for the control plane machines.
- 8 9
- Provides name resolution for the compute machines.
Example DNS PTR record configuration for a user-provisioned cluster
The following example BIND zone file shows sample PTR records for reverse name resolution in a user-provisioned cluster.
Example 16.2. Sample DNS zone database for reverse records
- 1
- Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer.
- 2
- Provides reverse DNS resolution for the Kubernetes API. The PTR record refers to the record name of the API load balancer and is used for internal cluster communications.
- 3
- Provides reverse DNS resolution for the bootstrap machine.
- 4 5 6
- Provides reverse DNS resolution for the control plane machines.
- 7 8
- Provides reverse DNS resolution for the compute machines.
A PTR record is not required for the OpenShift Container Platform application wildcard.
16.1.3.6. Load balancing requirements for user-provisioned infrastructure
Before you install OpenShift Container Platform, you must provision the API and application ingress load balancing infrastructure. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.
If you want to deploy the API and application ingress load balancers with a Red Hat Enterprise Linux (RHEL) instance, you must purchase the RHEL subscription separately.
The load balancing infrastructure must 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: - Expand - Table 16.7. 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 - /readyzendpoint 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 - /readyzendpoint to the removal of the API server instance from the pool. Within the time frame after- /readyzreturns 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.
 Tip- If the true IP address of the client can be seen by the application ingress load balancer, enabling source IP-based session persistence can improve performance for applications that use end-to-end TLS encryption. - Configure the following ports on both the front and back of the load balancers: - Expand - Table 16.8. Application ingress load balancer - Port - Back-end machines (pool members) - Internal - External - Description - 443- The machines that run the Ingress Controller pods, compute, or worker, by default. - X - X - HTTPS traffic - 80- The machines that run the Ingress Controller pods, compute, or worker, by default. - X - X - HTTP traffic - 1936- The worker nodes that run the Ingress Controller pods, by default. You must configure the - /healthz/readyendpoint for the ingress health check probe.- X - X - HTTP traffic 
If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes.
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.
16.1.3.6.1. Example load balancer configuration for user-provisioned clusters
							This section provides an example API and application ingress load balancer configuration that meets the load balancing requirements for user-provisioned clusters. The sample is an /etc/haproxy/haproxy.cfg configuration for an HAProxy load balancer. The example is not meant to provide advice for choosing one load balancing solution over another.
						
In the example, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation.
Example 16.3. Sample API and application ingress load balancer configuration
- 1
- In the example, the cluster name isocp4.
- 2
- Port6443handles the Kubernetes API traffic and points to the control plane machines.
- 3 5
- The bootstrap entries must be in place before the OpenShift Container Platform cluster installation and they must be removed after the bootstrap process is complete.
- 4
- Port22623handles the machine config server traffic and points to the control plane machines.
- 6
- Port443handles the HTTPS traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.
- 7
- Port80handles the HTTP traffic and points to the machines that run the Ingress Controller pods. The Ingress Controller pods run on the compute machines by default.NoteIf you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes. 
							If you are using HAProxy as a load balancer, you can check that the haproxy process is listening on ports 6443, 22623, 443, and 80 by running netstat -nltupe on the HAProxy node.
						
								If you are using HAProxy as a load balancer and SELinux is set to enforcing, you must ensure that the HAProxy service can bind to the configured TCP port by running setsebool -P haproxy_connect_any=1.
							
16.1.4. Preparing the user-provisioned infrastructure
Before you install OpenShift Container Platform on user-provisioned infrastructure, you must prepare the underlying infrastructure.
This section provides details about the high-level steps required to set up your cluster infrastructure in preparation for an OpenShift Container Platform installation. This includes configuring IP networking and network connectivity for your cluster nodes, preparing a web server for the Ignition files, enabling the required ports through your firewall, and setting up the required DNS and load balancing infrastructure.
After preparation, your cluster infrastructure must meet the requirements outlined in the Requirements for a cluster with user-provisioned infrastructure section.
Prerequisites
- You have reviewed the OpenShift Container Platform 4.x Tested Integrations page.
- You have reviewed the infrastructure requirements detailed in the Requirements for a cluster with user-provisioned infrastructure section.
Procedure
- Set up static IP addresses.
- Set up an HTTP or HTTPS server to provide Ignition files to the cluster nodes.
- Ensure that your network infrastructure provides the required network connectivity between the cluster components. See the Networking requirements for user-provisioned infrastructure section for details about the requirements.
- Configure your firewall to enable the ports required for the OpenShift Container Platform cluster components to communicate. See Networking requirements for user-provisioned infrastructure section for details about the ports that are required.
- Setup the required DNS infrastructure for your cluster. - Configure DNS name resolution for the Kubernetes API, the application wildcard, the bootstrap machine, the control plane machines, and the compute machines.
- Configure reverse DNS resolution for the Kubernetes API, the bootstrap machine, the control plane machines, and the compute machines. - See the User-provisioned DNS requirements section for more information about the OpenShift Container Platform DNS requirements. 
 
- Validate your DNS configuration. - From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses in the responses correspond to the correct components.
- From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names in the responses correspond to the correct components. - See the Validating DNS resolution for user-provisioned infrastructure section for detailed DNS validation steps. 
 
- Provision the required API and application ingress load balancing infrastructure. See the Load balancing requirements for user-provisioned infrastructure section for more information about the requirements.
Some load balancing solutions require the DNS name resolution for the cluster nodes to be in place before the load balancing is initialized.
16.1.5. Validating DNS resolution for user-provisioned infrastructure
You can validate your DNS configuration before installing OpenShift Container Platform on user-provisioned infrastructure.
The validation steps detailed in this section must succeed before you install your cluster.
Prerequisites
- You have configured the required DNS records for your user-provisioned infrastructure.
Procedure
- From your installation node, run DNS lookups against the record names of the Kubernetes API, the wildcard routes, and the cluster nodes. Validate that the IP addresses contained in the responses correspond to the correct components. - Perform a lookup against the Kubernetes API record name. Check that the result points to the IP address of the API load balancer: - dig +noall +answer @<nameserver_ip> api.<cluster_name>.<base_domain> - $ dig +noall +answer @<nameserver_ip> api.<cluster_name>.<base_domain>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- Replace<nameserver_ip>with the IP address of the nameserver,<cluster_name>with your cluster name, and<base_domain>with your base domain name.
 - Example output - api.ocp4.example.com. 0 IN A 192.168.1.5 - api.ocp4.example.com. 0 IN A 192.168.1.5- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Perform a lookup against the Kubernetes internal API record name. Check that the result points to the IP address of the API load balancer: - dig +noall +answer @<nameserver_ip> api-int.<cluster_name>.<base_domain> - $ dig +noall +answer @<nameserver_ip> api-int.<cluster_name>.<base_domain>- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - api-int.ocp4.example.com. 0 IN A 192.168.1.5 - api-int.ocp4.example.com. 0 IN A 192.168.1.5- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Test an example - *.apps.<cluster_name>.<base_domain>DNS wildcard lookup. All of the application wildcard lookups must resolve to the IP address of the application ingress load balancer:- dig +noall +answer @<nameserver_ip> random.apps.<cluster_name>.<base_domain> - $ dig +noall +answer @<nameserver_ip> random.apps.<cluster_name>.<base_domain>- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - random.apps.ocp4.example.com. 0 IN A 192.168.1.5 - random.apps.ocp4.example.com. 0 IN A 192.168.1.5- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- In the example outputs, the same load balancer is used for the Kubernetes API and application ingress traffic. In production scenarios, you can deploy the API and application ingress load balancers separately so that you can scale the load balancer infrastructure for each in isolation. - You can replace - randomwith another wildcard value. For example, you can query the route to the OpenShift Container Platform console:- dig +noall +answer @<nameserver_ip> console-openshift-console.apps.<cluster_name>.<base_domain> - $ dig +noall +answer @<nameserver_ip> console-openshift-console.apps.<cluster_name>.<base_domain>- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - console-openshift-console.apps.ocp4.example.com. 0 IN A 192.168.1.5 - console-openshift-console.apps.ocp4.example.com. 0 IN A 192.168.1.5- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Run a lookup against the bootstrap DNS record name. Check that the result points to the IP address of the bootstrap node: - dig +noall +answer @<nameserver_ip> bootstrap.<cluster_name>.<base_domain> - $ dig +noall +answer @<nameserver_ip> bootstrap.<cluster_name>.<base_domain>- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - bootstrap.ocp4.example.com. 0 IN A 192.168.1.96 - bootstrap.ocp4.example.com. 0 IN A 192.168.1.96- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Use this method to perform lookups against the DNS record names for the control plane and compute nodes. Check that the results correspond to the IP addresses of each node.
 
- From your installation node, run reverse DNS lookups against the IP addresses of the load balancer and the cluster nodes. Validate that the record names contained in the responses correspond to the correct components. - Perform a reverse lookup against the IP address of the API load balancer. Check that the response includes the record names for the Kubernetes API and the Kubernetes internal API: - dig +noall +answer @<nameserver_ip> -x 192.168.1.5 - $ dig +noall +answer @<nameserver_ip> -x 192.168.1.5- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - 5.1.168.192.in-addr.arpa. 0 IN PTR api-int.ocp4.example.com. 5.1.168.192.in-addr.arpa. 0 IN PTR api.ocp4.example.com. - 5.1.168.192.in-addr.arpa. 0 IN PTR api-int.ocp4.example.com.- 1 - 5.1.168.192.in-addr.arpa. 0 IN PTR api.ocp4.example.com.- 2 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- A PTR record is not required for the OpenShift Container Platform application wildcard. No validation step is needed for reverse DNS resolution against the IP address of the application ingress load balancer. 
- Perform a reverse lookup against the IP address of the bootstrap node. Check that the result points to the DNS record name of the bootstrap node: - dig +noall +answer @<nameserver_ip> -x 192.168.1.96 - $ dig +noall +answer @<nameserver_ip> -x 192.168.1.96- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - 96.1.168.192.in-addr.arpa. 0 IN PTR bootstrap.ocp4.example.com. - 96.1.168.192.in-addr.arpa. 0 IN PTR bootstrap.ocp4.example.com.- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Use this method to perform reverse lookups against the IP addresses for the control plane and compute nodes. Check that the results correspond to the DNS record names of each node.
 
16.1.6. Generating a key pair for cluster node SSH access
					During an OpenShift Container Platform installation, you can provide an SSH public key to the installation program. The key is passed to the Red Hat Enterprise Linux CoreOS (RHCOS) nodes through their Ignition config files and is used to authenticate SSH access to the nodes. The key is added to the ~/.ssh/authorized_keys list for the core user on each node, which enables password-less authentication.
				
					After the key is passed to the nodes, you can use the key pair to SSH in to the RHCOS nodes as the user core. To access the nodes through SSH, the private key identity must be managed by SSH for your local user.
				
					If you want to SSH in to your cluster nodes to perform installation debugging or disaster recovery, you must provide the SSH public key during the installation process. The ./openshift-install gather command also requires the SSH public key to be in place on the cluster nodes.
				
Do not skip this procedure in production environments, where disaster recovery and debugging is required.
Procedure
- If you do not have an existing SSH key pair on your local machine to use for authentication onto your cluster nodes, 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> - $ ssh-keygen -t ed25519 -N '' -f <path>/<file_name>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- Specify the path and file name, such as~/.ssh/id_ed25519, of the new SSH key. If you have an existing key pair, ensure your public key is in the your~/.sshdirectory.
 Note- If you plan to install an OpenShift Container Platform cluster that uses FIPS Validated / Modules in Process cryptographic libraries on the - x86_64architecture, do not create a key that uses the- ed25519algorithm. Instead, create a key that uses the- rsaor- ecdsaalgorithm.
- View the public SSH key: - cat <path>/<file_name>.pub - $ cat <path>/<file_name>.pub- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - For example, run the following to view the - ~/.ssh/id_ed25519.pubpublic key:- cat ~/.ssh/id_ed25519.pub - $ cat ~/.ssh/id_ed25519.pub- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Add the SSH private key identity to the SSH agent for your local user, if it has not already been added. SSH agent management of the key is required for password-less SSH authentication onto your cluster nodes, or if you want to use the - ./openshift-install gathercommand.Note- On some distributions, default SSH private key identities such as - ~/.ssh/id_rsaand- ~/.ssh/id_dsaare managed automatically.- If the - ssh-agentprocess is not already running for your local user, start it as a background task:- eval "$(ssh-agent -s)" - $ eval "$(ssh-agent -s)"- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Agent pid 31874 - Agent pid 31874- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- 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> - $ ssh-add <path>/<file_name>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- Specify the path and file name for your SSH private key, such as~/.ssh/id_ed25519
 - Example output - Identity added: /home/<you>/<path>/<file_name> (<computer_name>) - Identity added: /home/<you>/<path>/<file_name> (<computer_name>)- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
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 the key to the installation program.
16.1.7. Obtaining the installation program
Before you install OpenShift Container Platform, download the installation file on your provisioning machine.
Prerequisites
- You have a machine that runs Linux, for example Red Hat Enterprise Linux 8, with 500 MB of local disk space
Procedure
- Access the Infrastructure Provider page on the OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.
- Select your infrastructure provider.
- 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 the installation program and the files that the installation program creates after you finish installing the cluster. Both files are required to delete the cluster. Important- Deleting the files created by the installation program does not remove your cluster, even if the cluster failed during installation. To remove your cluster, complete the OpenShift Container Platform uninstallation procedures for your specific cloud provider. 
- Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command: - tar xvf openshift-install-linux.tar.gz - $ tar xvf openshift-install-linux.tar.gz- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Download your installation pull secret from the Red Hat OpenShift Cluster Manager. 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.
16.1.8. Installing the OpenShift CLI by downloading the binary
					You can install the OpenShift CLI (oc) to interact with OpenShift Container Platform from a command-line interface. You can install oc on Linux, Windows, or macOS.
				
						If you installed an earlier version of oc, you cannot use it to complete all of the commands in OpenShift Container Platform 4.8. Download and install the new version of oc.
					
Installing the OpenShift CLI on Linux
					You can install the OpenShift CLI (oc) binary on Linux by using the following procedure.
				
Procedure
- Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
- Select the appropriate version in the Version drop-down menu.
- Click Download Now next to the OpenShift v4.8 Linux Client entry and save the file.
- Unpack the archive: - tar xvzf <file> - $ tar xvzf <file>- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Place the - ocbinary in a directory that is on your- PATH.- To check your - PATH, execute the following command:- echo $PATH - $ echo $PATH- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
					After you install the OpenShift CLI, it is available using the oc command:
				
oc <command>
$ oc <command>Installing the OpenShift CLI on Windows
					You can install the OpenShift CLI (oc) binary on Windows by using the following procedure.
				
Procedure
- Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
- Select the appropriate version in the Version drop-down menu.
- Click Download Now next to the OpenShift v4.8 Windows Client entry and save the file.
- Unzip the archive with a ZIP program.
- Move the - ocbinary to a directory that is on your- PATH.- To check your - PATH, open the command prompt and execute the following command:- path - C:\> path- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
					After you install the OpenShift CLI, it is available using the oc command:
				
oc <command>
C:\> oc <command>Installing the OpenShift CLI on macOS
					You can install the OpenShift CLI (oc) binary on macOS by using the following procedure.
				
Procedure
- Navigate to the OpenShift Container Platform downloads page on the Red Hat Customer Portal.
- Select the appropriate version in the Version drop-down menu.
- Click Download Now next to the OpenShift v4.8 MacOSX Client entry and save the file.
- Unpack and unzip the archive.
- Move the - ocbinary to a directory on your PATH.- To check your - PATH, open a terminal and execute the following command:- echo $PATH - $ echo $PATH- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
					After you install the OpenShift CLI, it is available using the oc command:
				
oc <command>
$ oc <command>16.1.9. Manually creating the installation configuration file
For user-provisioned installations of OpenShift Container Platform, you manually generate your installation configuration file.
Prerequisites
- You have an SSH public key on your local machine to provide to the installation program. The key will be used for SSH authentication onto your cluster nodes for debugging and disaster recovery.
- You have obtained the OpenShift Container Platform installation program and the pull secret for your cluster.
Procedure
- Create an installation directory to store your required installation assets in: - mkdir <installation_directory> - $ mkdir <installation_directory>- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 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 sample - install-config.yamlfile template that is provided and save it in the- <installation_directory>.Note- You must name this configuration file - install-config.yaml.Note- For some platform types, you can alternatively run - ./openshift-install create install-config --dir <installation_directory>to generate an- install-config.yamlfile. You can provide details about your cluster configuration at the prompts.
- Back up the - install-config.yamlfile so that you can use it to install multiple clusters.Important- The - install-config.yamlfile is consumed during the next step of the installation process. You must back it up now.
16.1.9.1. Sample install-config.yaml file for IBM Z
16.1.9.2. Sample install-config.yaml file for other platforms
						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.
					
- 1
- The base domain of the cluster. All DNS records must be sub-domains of this base and include the cluster name.
- 2 5
- ThecontrolPlanesection is a single mapping, but thecomputesection is a sequence of mappings. To meet the requirements of the different data structures, the first line of thecomputesection must begin with a hyphen,-, and the first line of thecontrolPlanesection must not. Only one control plane pool is used.
- 3 6
- Specifies whether to enable or disable simultaneous multithreading (SMT), or hyperthreading. By default, SMT is enabled to increase the performance of the cores in your machines. You can disable it by setting the parameter value toDisabled. If you disable SMT, you must disable it in all cluster machines; this includes both control plane and compute machines.NoteSimultaneous multithreading (SMT) is enabled by default. If SMT is not enabled in your BIOS settings, the hyperthreadingparameter has no effect.ImportantIf you disable hyperthreading, whether in the BIOS or in theinstall-config.yaml, ensure that your capacity planning accounts for the dramatically decreased machine performance.
- 4
- You must set this value to0when you install OpenShift Container Platform on user-provisioned infrastructure. In installer-provisioned installations, the parameter controls the number of compute machines that the cluster creates and manages for you. In user-provisioned installations, you must manually deploy the compute machines before you finish installing the cluster.NoteIf you are installing a three-node cluster, do not deploy any compute machines when you install the Red Hat Enterprise Linux CoreOS (RHCOS) machines. 
- 7
- The number of control plane machines that you add to the cluster. Because the cluster uses these 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.NoteClass E CIDR range is reserved for a future use. To use the Class E CIDR range, you must ensure your networking environment accepts the IP addresses within the Class E CIDR range. 
- 10
- The subnet prefix length to assign to each individual node. For example, ifhostPrefixis set to23, then each node is assigned a/23subnet out of the givencidr, which allows for 510 (2^(32 - 23) - 2) pod IP 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. This block must not overlap with existing physical networks. 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 tonone. You cannot provide additional platform configuration variables for IBM Z infrastructure.WarningRed Hat Virtualization does not currently support installation with user-provisioned infrastructure on the oVirt platform. Therefore, you must set the platform to none, allowing OpenShift Container Platform to identify each node as a bare-metal node and the cluster as a bare-metal cluster. This is the same as installing a cluster on any platform, and has the following limitations:- There will be no cluster provider so you must manually add each machine and there will be no node scaling capabilities.
- The oVirt CSI driver will not be installed and there will be no CSI capabilities.
 
- 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.ImportantThe use of FIPS Validated / Modules in Process cryptographic libraries is only supported on OpenShift Container Platform deployments on the x86_64architecture.
- 14
- The pull secret from the Red Hat OpenShift Cluster Manager. 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 SSH public key for thecoreuser in Red Hat Enterprise Linux CoreOS (RHCOS).NoteFor production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your ssh-agentprocess uses.
16.1.9.3. 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.
					
Prerequisites
- 
								You have an existing install-config.yamlfile.
- You reviewed the sites that your cluster requires access to and determined whether any of them need to bypass the proxy. By default, all cluster egress traffic is proxied, including calls to hosting cloud provider APIs. You added sites to the - Proxyobject’s- spec.noProxyfield to bypass the proxy if necessary.Note- The - Proxyobject- status.noProxyfield 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 - Proxyobject- status.noProxyfield is also populated with the instance metadata endpoint (- 169.254.169.254).
Procedure
- Edit your - install-config.yamlfile and add the proxy settings. For example:- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- A proxy URL to use for creating HTTP connections outside the cluster. The URL scheme must behttp.
- 2
- A proxy URL to use for creating HTTPS connections outside the cluster.
- 3
- A comma-separated list of destination domain names, IP addresses, or other network CIDRs to exclude from proxying. Preface a domain with.to match subdomains only. For example,.y.commatchesx.y.com, but noty.com. Use*to bypass the proxy for all destinations.
- 4
- If provided, the installation program generates a config map that is nameduser-ca-bundlein theopenshift-confignamespace to hold the additional CA certificates. If you provideadditionalTrustBundleand at least one proxy setting, theProxyobject is configured to reference theuser-ca-bundleconfig map in thetrustedCAfield. The Cluster Network Operator then creates atrusted-ca-bundleconfig map that merges the contents specified for thetrustedCAparameter with the RHCOS trust bundle. TheadditionalTrustBundlefield is required unless the proxy’s identity certificate is signed by an authority from the RHCOS trust bundle.
 Note- The installation program does not support the proxy - readinessEndpointsfield.
- 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.
					
							Only the Proxy object named cluster is supported, and no additional proxies can be created.
						
16.1.9.4. Configuring a three-node cluster
You can optionally deploy zero compute machines in a bare metal cluster that consists of three control plane machines only. This provides smaller, more resource efficient clusters for cluster administrators and developers to use for testing, development, and production.
In three-node OpenShift Container Platform environments, the three control plane machines are schedulable, which means that your application workloads are scheduled to run on them.
Prerequisites
- 
								You have an existing install-config.yamlfile.
Procedure
- Ensure that the number of compute replicas is set to - 0in your- install-config.yamlfile, as shown in the following- computestanza:- compute: - name: worker platform: {} replicas: 0- compute: - name: worker platform: {} replicas: 0- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- You must set the value of the - replicasparameter for the compute machines to- 0when you install OpenShift Container Platform on user-provisioned infrastructure, regardless of the number of compute machines you are deploying. In installer-provisioned installations, the parameter controls the number of compute machines that the cluster creates and manages for you. This does not apply to user-provisioned installations, where the compute machines are deployed manually.Note- The preferred resource for control plane nodes is six vCPUs and 21 GB. For three control plane nodes this is the memory + vCPU equivalent of a minimum five-node cluster. You should back the three nodes, each installed on a 120 GB disk, with three IFLs that are SMT2 enabled. The minimum tested setup is three vCPUs and 10 GB on a 120 GB disk for each control plane node. 
For three-node cluster installations, follow these next steps:
- If you are deploying a three-node cluster with zero compute nodes, the Ingress Controller pods run on the control plane nodes. In three-node cluster deployments, you must configure your application ingress load balancer to route HTTP and HTTPS traffic to the control plane nodes. See the Load balancing requirements for user-provisioned infrastructure section for more information.
- 
								When you create the Kubernetes manifest files in the following procedure, ensure that the mastersSchedulableparameter in the<installation_directory>/manifests/cluster-scheduler-02-config.ymlfile is set totrue. This enables your application workloads to run on the control plane nodes.
- Do not deploy any compute nodes when you create the Red Hat Enterprise Linux CoreOS (RHCOS) machines.
16.1.10. 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 configure the machines.
The installation configuration file transforms into the Kubernetes manifests. The manifests wrap into the Ignition configuration files, which are later used to configure the cluster machines.
- 
								The Ignition config files that the OpenShift Container Platform 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-bootstrappercertificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
- It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.
The installation program that generates the manifest and Ignition files is architecture specific and can be obtained from the client image mirror. The Linux version of the installation program runs on s390x only. This installer program is also available as a Mac OS version.
Prerequisites
- You obtained the OpenShift Container Platform installation program.
- 
							You created the install-config.yamlinstallation configuration file.
Procedure
- Change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster: - ./openshift-install create manifests --dir <installation_directory> - $ ./openshift-install create manifests --dir <installation_directory>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- For<installation_directory>, specify the installation directory that contains theinstall-config.yamlfile you created.
 Warning- If you are installing a three-node cluster, skip the following step to allow the control plane nodes to be schedulable. Important- When you configure control plane nodes from the default unschedulable to schedulable, additional subscriptions are required. This is because control plane nodes then become worker nodes. 
- Check that the - mastersSchedulableparameter in the- <installation_directory>/manifests/cluster-scheduler-02-config.ymlKubernetes manifest file is set to- false. This setting prevents pods from being scheduled on the control plane machines:- 
									Open the <installation_directory>/manifests/cluster-scheduler-02-config.ymlfile.
- 
									Locate the mastersSchedulableparameter and ensure that it is set tofalse.
- Save and exit the file.
 
- 
									Open the 
- To create the Ignition configuration files, run the following command from the directory that contains the installation program: - ./openshift-install create ignition-configs --dir <installation_directory> - $ ./openshift-install create ignition-configs --dir <installation_directory>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- For<installation_directory>, specify the same installation directory.
 - Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory. The - kubeadmin-passwordand- kubeconfigfiles are created in the- ./<installation_directory>/authdirectory:- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
16.1.11. Installing RHCOS and starting the OpenShift Container Platform bootstrap process
To install OpenShift Container Platform on bare metal infrastructure that you provision, you must install Red Hat Enterprise Linux CoreOS (RHCOS) on the machines. When you install RHCOS, you must provide the Ignition config file that was generated by the OpenShift Container Platform installation program for the type of machine you are installing. If you have configured suitable networking, DNS, and load balancing infrastructure, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS machines have rebooted.
To install RHCOS on the machines, follow either the steps to use an ISO image or network PXE booting.
The compute node deployment steps included in this installation document are RHCOS-specific. If you choose instead to deploy RHEL-based compute nodes, you take responsibility for all operating system life cycle management and maintenance, including performing system updates, applying patches, and completing all other required tasks. Use of RHEL 7 compute machines is deprecated and planned for removal in a future release of OpenShift Container Platform 4.
You can configure RHCOS during ISO and PXE installations by using the following methods:
- 
							Kernel arguments: You can use kernel arguments to provide installation-specific information. For example, you can specify the locations of the RHCOS installation files that you uploaded to your HTTP server and the location of the Ignition config file for the type of node you are installing. For a PXE installation, you can use the APPENDparameter to pass the arguments to the kernel of the live installer. For an ISO installation, you can interrupt the live installation boot process to add the kernel arguments. In both installation cases, you can use specialcoreos.inst.*arguments to direct the live installer, as well as standard installation boot arguments for turning standard kernel services on or off.
- 
							Ignition configs: OpenShift Container Platform Ignition config files (*.ign) are specific to the type of node you are installing. You pass the location of a bootstrap, control plane, or compute node Ignition config file during the RHCOS installation so that it takes effect on first boot. In special cases, you can create a separate, limited Ignition config to pass to the live system. That Ignition config could do a certain set of tasks, such as reporting success to a provisioning system after completing installation. This special Ignition config is consumed by thecoreos-installerto be applied on first boot of the installed system. Do not provide the standard control plane and compute node Ignition configs to the live ISO directly.
- 
							coreos-installer: You can boot the live ISO installer to a shell prompt, which allows you to prepare the permanent system in a variety of ways before first boot. In particular, you can run thecoreos-installercommand to identify various artifacts to include, work with disk partitions, and set up networking. In some cases, you can configure features on the live system and copy them to the installed system.
Whether to use an ISO or PXE install depends on your situation. A PXE install requires an available DHCP service and more preparation, but can make the installation process more automated. An ISO install is a more manual process and can be inconvenient if you are setting up more than a few machines.
As of OpenShift Container Platform 4.6, the RHCOS ISO and other installation artifacts provide support for installation on disks with 4K sectors.
16.1.11.1. Installing RHCOS by using an ISO image
You can use an ISO image to install RHCOS on the machines.
Prerequisites
- You have created the Ignition config files for your cluster.
- You have configured suitable network, DNS and load balancing infrastructure.
- You have an HTTP server that can be accessed from your computer, and from the machines that you create.
- You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.
Procedure
- Obtain the SHA512 digest for each of your Ignition config files. For example, you can use the following on a system running Linux to get the SHA512 digest for your - bootstrap.ignIgnition config file:- sha512sum <installation_directory>/bootstrap.ign - $ sha512sum <installation_directory>/bootstrap.ign- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - The digests are provided to the - coreos-installerin a later step to validate the authenticity of the Ignition config files on the cluster nodes.
- Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files. Important- You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files. 
- From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node: - curl -k http://<HTTP_server>/bootstrap.ign - $ curl -k http://<HTTP_server>/bootstrap.ign- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...- % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Replace - bootstrap.ignwith- master.ignor- worker.ignin the command to validate that the Ignition config files for the control plane and compute nodes are also available.
- Although it is possible to obtain the RHCOS images that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS images are from the output of - openshift-installcommand:- openshift-install coreos print-stream-json | grep '\.iso[^.]' - $ openshift-install coreos print-stream-json | grep '\.iso[^.]'- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - "location": "<url>/art/storage/releases/rhcos-4.8-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso", "location": "<url>/art/storage/releases/rhcos-4.8-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso", "location": "<url>/art/storage/releases/rhcos-4.8-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso", "location": "<url>/art/storage/releases/rhcos-4.8/<release>/x86_64/rhcos-<release>-live.x86_64.iso", - "location": "<url>/art/storage/releases/rhcos-4.8-aarch64/<release>/aarch64/rhcos-<release>-live.aarch64.iso", "location": "<url>/art/storage/releases/rhcos-4.8-ppc64le/<release>/ppc64le/rhcos-<release>-live.ppc64le.iso", "location": "<url>/art/storage/releases/rhcos-4.8-s390x/<release>/s390x/rhcos-<release>-live.s390x.iso", "location": "<url>/art/storage/releases/rhcos-4.8/<release>/x86_64/rhcos-<release>-live.x86_64.iso",- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 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. Use only ISO images for this procedure. RHCOS qcow2 images are not supported for this installation type. - ISO file names resemble the following example: - rhcos-<version>-live.<architecture>.iso
- 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 by using a lights-out management (LOM) interface.
 
- Boot the RHCOS ISO image without specifying any options or interrupting the live boot sequence. Wait for the installer to boot into a shell prompt in the RHCOS live environment. Note- It is possible to interrupt the RHCOS installation boot process to add kernel arguments. However, for this ISO procedure you should use the - coreos-installercommand as outlined in the following steps, instead of adding kernel arguments.
- Run the - coreos-installercommand and specify the options that meet your installation requirements. At a minimum, you must specify the URL that points to the Ignition config file for the node type, and the device that you are installing to:- sudo coreos-installer install --ignition-url=http://<HTTP_server>/<node_type>.ign <device> --ignition-hash=sha512-<digest> - $ sudo coreos-installer install --ignition-url=http://<HTTP_server>/<node_type>.ign <device> --ignition-hash=sha512-<digest>- 1 - 2 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1 1
- You must run thecoreos-installercommand by usingsudo, because thecoreuser does not have the required root privileges to perform the installation.
- 2
- The--ignition-hashoption is required when the Ignition config file is obtained through an HTTP URL to validate the authenticity of the Ignition config file on the cluster node.<digest>is the Ignition config file SHA512 digest obtained in a preceding step.
 Note- If you want to provide your Ignition config files through an HTTPS server that uses TLS, you can add the internal certificate authority (CA) to the system trust store before running - coreos-installer.- The following example initializes a bootstrap node installation to the - /dev/sdadevice. The Ignition config file for the bootstrap node is obtained from an HTTP web server with the IP address 192.168.1.2:- sudo coreos-installer install --ignition-url=http://192.168.1.2:80/installation_directory/bootstrap.ign /dev/sda --ignition-hash=sha512-a5a2d43879223273c9b60af66b44202a1d1248fc01cf156c46d4a79f552b6bad47bc8cc78ddf0116e80c59d2ea9e32ba53bc807afbca581aa059311def2c3e3b - $ sudo coreos-installer install --ignition-url=http://192.168.1.2:80/installation_directory/bootstrap.ign /dev/sda --ignition-hash=sha512-a5a2d43879223273c9b60af66b44202a1d1248fc01cf156c46d4a79f552b6bad47bc8cc78ddf0116e80c59d2ea9e32ba53bc807afbca581aa059311def2c3e3b- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Monitor the progress of the RHCOS installation on the console of the machine. Important- Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise. 
- After RHCOS installs, the system reboots. During the system reboot, it applies the Ignition config file that you specified.
- Continue to create the other 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, also create at least two compute machines before you install OpenShift Container Platform. - If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted. Note- RHCOS nodes do not include a default password for the - coreuser. You can access the nodes by running- ssh core@<node>.<cluster_name>.<base_domain>as a user with access to the SSH private key that is paired to the public key that you specified in your- install_config.yamlfile. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.
16.1.11.2. Installing RHCOS by using PXE or iPXE booting
You can use PXE or iPXE booting to install RHCOS on the machines.
Prerequisites
- You have created the Ignition config files for your cluster.
- You have configured suitable network, DNS and load balancing infrastructure.
- You have configured suitable PXE or iPXE infrastructure.
- You have an HTTP server that can be accessed from your computer, and from the machines that you create.
- You have reviewed the Advanced RHCOS installation configuration section for different ways to configure features, such as networking and disk partitioning.
Procedure
- Upload the bootstrap, control plane, and compute node Ignition config files that the installation program created to your HTTP server. Note the URLs of these files. Important- You can add or change configuration settings in your Ignition configs before saving them to your HTTP server. If you plan to add more compute machines to your cluster after you finish installation, do not delete these files. 
- From the installation host, validate that the Ignition config files are available on the URLs. The following example gets the Ignition config file for the bootstrap node: - curl -k http://<HTTP_server>/bootstrap.ign - $ curl -k http://<HTTP_server>/bootstrap.ign- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...- % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0{"ignition":{"version":"3.2.0"},"passwd":{"users":[{"name":"core","sshAuthorizedKeys":["ssh-rsa...- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Replace - bootstrap.ignwith- master.ignor- worker.ignin the command to validate that the Ignition config files for the control plane and compute nodes are also available.
- Although it is possible to obtain the RHCOS - kernel,- initramfsand- rootfsfiles that are required for your preferred method of installing operating system instances from the RHCOS image mirror page, the recommended way to obtain the correct version of your RHCOS files are from the output of- openshift-installcommand:- openshift-install coreos print-stream-json | grep -Eo '"https.*(kernel-|initramfs.|rootfs.)\w+(\.img)?"' - $ openshift-install coreos print-stream-json | grep -Eo '"https.*(kernel-|initramfs.|rootfs.)\w+(\.img)?"'- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Important- The RHCOS artifacts 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. Only use the appropriate - kernel,- initramfs, and- rootfsartifacts described below for this procedure. RHCOS QCOW2 images are not supported for this installation type.- The file names contain the OpenShift Container Platform version number. They resemble the following examples: - 
										kernel:rhcos-<version>-live-kernel-<architecture>
- 
										initramfs:rhcos-<version>-live-initramfs.<architecture>.img
- 
										rootfs:rhcos-<version>-live-rootfs.<architecture>.img
 
- 
										
- Upload the additional files that are required for your booting method: - 
										For traditional PXE, upload the kernelandinitramfsfiles to your TFTP server and therootfsfile to your HTTP server.
- For iPXE, upload the - kernel,- initramfs, and- rootfsfiles 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. 
 
- 
										For traditional PXE, upload the 
- 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 and begin the installation. - Modify one of the following example menu entries for your environment and verify that the image and Ignition files are properly accessible: - For PXE: - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1 1
- Specify the location of the livekernelfile that you uploaded to your HTTP server. The URL must be HTTP, TFTP, or FTP; HTTPS and NFS are not supported.
- 2
- If you use multiple NICs, specify a single interface in theipoption. For example, to use DHCP on a NIC that is namedeno1, setip=eno1:dhcp.
- 3
- Specify the locations of the RHCOS files that you uploaded to your HTTP server. Theinitrdparameter value is the location of theinitramfsfile, thecoreos.live.rootfs_urlparameter value is the location of therootfsfile, and thecoreos.inst.ignition_urlparameter value is the location of the bootstrap Ignition config file. You can also add more kernel arguments to theAPPENDline to configure networking or other boot options.
 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- APPENDline. For example, add- console=tty0 console=ttyS0to 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>-live-kernel-<architecture> initrd=main coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign initrd --name main http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img boot - kernel http://<HTTP_server>/rhcos-<version>-live-kernel-<architecture> initrd=main coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.install_dev=/dev/sda coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign- 1 - 2 - initrd --name main http://<HTTP_server>/rhcos-<version>-live-initramfs.<architecture>.img- 3 - boot- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- Specify the locations of the RHCOS files that you uploaded to your HTTP server. Thekernelparameter value is the location of thekernelfile, theinitrd=mainargument is needed for booting on UEFI systems, thecoreos.live.rootfs_urlparameter value is the location of therootfsfile, and thecoreos.inst.ignition_urlparameter value is the location of the bootstrap Ignition config file.
- 2
- If you use multiple NICs, specify a single interface in theipoption. For example, to use DHCP on a NIC that is namedeno1, setip=eno1:dhcp.
- 3
- Specify the location of theinitramfsfile 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- kernelline. For example, add- console=tty0 console=ttyS0to 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 PXE UEFI, perform the following actions: - Provide the - shimx64.efiand- grubx64.efiEFI binaries and the- grub.cfgfile that are required for booting the system.- Extract the necessary EFI binaries by mounting the RHCOS ISO to your host and then mounting the - images/efiboot.imgfile to your host:- mkdir -p /mnt/iso - $ mkdir -p /mnt/iso- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - mkdir -p /mnt/efiboot - $ mkdir -p /mnt/efiboot- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - mount -o loop rhcos-installer.x86_64.iso /mnt/iso - $ mount -o loop rhcos-installer.x86_64.iso /mnt/iso- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot - $ mount -o loop,ro /mnt/iso/images/efiboot.img /mnt/efiboot- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- From the - efiboot.imgmount point, copy the- EFI/redhat/shimx64.efiand- EFI/redhat/grubx64.efifiles to your TFTP server:- cp /mnt/efiboot/EFI/redhat/shimx64.efi . - $ cp /mnt/efiboot/EFI/redhat/shimx64.efi .- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - cp /mnt/efiboot/EFI/redhat/grubx64.efi . - $ cp /mnt/efiboot/EFI/redhat/grubx64.efi .- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - umount /mnt/efiboot - $ umount /mnt/efiboot- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - umount /mnt/iso - $ umount /mnt/iso- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- 
												Copy the EFI/redhat/grub.cfgfile that is included in the RHCOS ISO to your TFTP server.
 
- Edit the - grub.cfgfile to include arguments similar to the following:- menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os { linuxefi rhcos-<version>-live-kernel-<architecture> coreos.inst.install_dev=/dev/sda coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign initrdefi rhcos-<version>-live-initramfs.<architecture>.img }- menuentry 'Install Red Hat Enterprise Linux CoreOS' --class fedora --class gnu-linux --class gnu --class os { linuxefi rhcos-<version>-live-kernel-<architecture> coreos.inst.install_dev=/dev/sda coreos.live.rootfs_url=http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img coreos.inst.ignition_url=http://<HTTP_server>/bootstrap.ign initrdefi rhcos-<version>-live-initramfs.<architecture>.img }- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - where: - rhcos-<version>-live-kernel-<architecture>
- 
													Specifies the kernelfile that you uploaded to your TFTP server.
- http://<HTTP_server>/rhcos-<version>-live-rootfs.<architecture>.img
- Specifies the location of the live rootfs image that you uploaded to your HTTP server.
- http://<HTTP_server>/bootstrap.ign
- Specifies the location of the bootstrap Ignition config file that you uploaded to your HTTP server.
- rhcos-<version>-live-initramfs.<architecture>.img
- 
													Specifies the location of the initramfsfile that you uploaded to your TFTP server.
 Note- For more information on how to configure a PXE server for UEFI boot, see the Red Hat Knowledgebase article: How to configure/setup a PXE server for UEFI boot for Red Hat Enterprise Linux?. 
 
- Monitor the progress of the RHCOS installation on the console of the machine. Important- Be sure that the installation is successful on each node before commencing with the OpenShift Container Platform installation. Observing the installation process can also help to determine the cause of RHCOS installation issues that might arise. 
- After RHCOS installs, the system reboots. During reboot, the system 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, also create at least two compute machines before you install the cluster. - If the required network, DNS, and load balancer infrastructure are in place, the OpenShift Container Platform bootstrap process begins automatically after the RHCOS nodes have rebooted. Note- RHCOS nodes do not include a default password for the - coreuser. You can access the nodes by running- ssh core@<node>.<cluster_name>.<base_domain>as a user with access to the SSH private key that is paired to the public key that you specified in your- install_config.yamlfile. OpenShift Container Platform 4 cluster nodes running RHCOS are immutable and rely on Operators to apply cluster changes. Accessing cluster nodes by using SSH is not recommended. However, when investigating installation issues, if the OpenShift Container Platform API is not available, or the kubelet is not properly functioning on a target node, SSH access might be required for debugging or disaster recovery.
16.1.11.3. Advanced RHCOS installation configuration
A key benefit for manually provisioning the Red Hat Enterprise Linux CoreOS (RHCOS) nodes for OpenShift Container Platform is to be able to do configuration that is not available through default OpenShift Container Platform installation methods. This section describes some of the configurations that you can do using techniques that include:
- Passing kernel arguments to the live installer
- 
								Running coreos-installermanually from the live system
- Embedding Ignition configs in an ISO
The advanced configuration topics for manual Red Hat Enterprise Linux CoreOS (RHCOS) installations detailed in this section relate to disk partitioning, networking, and using Ignition configs in different ways.
16.1.11.3.1. Using advanced networking options for PXE and ISO installations
Networking for OpenShift Container Platform nodes uses DHCP by default to gather all necessary configuration settings. To set up static IP addresses or configure special settings, such as bonding, you can do one of the following:
- Pass special kernel parameters when you boot the live installer.
- Use a machine config to copy networking files to the installed system.
- Configure networking from a live installer shell prompt, then copy those settings to the installed system so that they take effect when the installed system first boots.
To configure a PXE or iPXE installation, use one of the following options:
- See the "Advanced RHCOS installation reference" tables.
- Use a machine config to copy networking files to the installed system.
To configure an ISO installation, use the following procedure.
Procedure
- Boot the ISO installer.
- 
									From the live system shell prompt, configure networking for the live system using available RHEL tools, such as nmcliornmtui.
- Run the - coreos-installercommand to install the system, adding the- --copy-networkoption to copy networking configuration. For example:- sudo coreos-installer install --copy-network \ --ignition-url=http://host/worker.ign /dev/sda- $ sudo coreos-installer install --copy-network \ --ignition-url=http://host/worker.ign /dev/sda- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Important- The - --copy-networkoption only copies networking configuration found under- /etc/NetworkManager/system-connections. In particular, it does not copy the system hostname.
- Reboot into the installed system.
16.1.11.3.2. Disk partitioning
The disk partitions are created on OpenShift Container Platform cluster nodes during the Red Hat Enterprise Linux CoreOS (RHCOS) installation. Each RHCOS node of a particular architecture uses the same partition layout, unless the default partitioning configuration is overridden. During the RHCOS installation, the size of the root file system is increased to use the remaining available space on the target device.
There are two cases where you might want to override the default partitioning when installing RHCOS on an OpenShift Container Platform cluster node:
- Creating separate partitions: For greenfield installations on an empty disk, you might want to add separate storage to a partition. This is officially supported for mounting - /varor a subdirectory of- /var, such as- /var/lib/etcd, on a separate partition, but not both.Important- Kubernetes supports only two file system partitions. If you add more than one partition to the original configuration, Kubernetes cannot monitor all of them. 
- 
									Retaining existing partitions: For a brownfield installation where you are reinstalling OpenShift Container Platform on an existing node and want to retain data partitions installed from your previous operating system, there are both boot arguments and options to coreos-installerthat allow you to retain existing data partitions.
The use of custom partitions could result in those partitions not being monitored by OpenShift Container Platform or alerted on. If you are overriding the default partitioning, see Understanding OpenShift File System Monitoring (eviction conditions) for more information about how OpenShift Container Platform monitors your host file systems.
16.1.11.3.2.1. Creating a separate /var partition
In general, you should use the default disk partitioning that is created during the RHCOS installation. However, there are cases where you might want to create a separate partition for a directory that you expect to grow.
								OpenShift Container Platform supports the addition of a single partition to attach storage to either the /var directory or a subdirectory of /var. For example:
							
- 
										/var/lib/containers: Holds container-related content that can grow as more images and containers are added to a system.
- 
										/var/lib/etcd: Holds data that you might want to keep separate for purposes such as performance optimization of etcd storage.
- 
										/var: Holds data that you might want to keep separate for purposes such as auditing.
								Storing the contents of a /var directory separately makes it easier to grow storage for those areas as needed and reinstall OpenShift Container Platform at a later date and keep that data intact. With this method, you will not have to pull all your containers again, nor will you have to copy massive log files when you update systems.
							
								The use of a separate partition for the /var directory or a subdirectory of /var also prevents data growth in the partitioned directory from filling up the root file system.
							
								The following procedure sets up a separate /var partition by adding a machine config manifest that is wrapped into the Ignition config file for a node type during the preparation phase of an installation.
							
Procedure
- On your installation host, change to the directory that contains the OpenShift Container Platform installation program and generate the Kubernetes manifests for the cluster: - openshift-install create manifests --dir <installation_directory> - $ openshift-install create manifests --dir <installation_directory>- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Create a Butane config that configures the additional partition. For example, name the file - $HOME/clusterconfig/98-var-partition.bu, change the disk device name to the name of the storage device on the- workersystems, and set the storage size as appropriate. This example places the- /vardirectory on a separate partition:- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- The storage device name of the disk that you want to partition.
- 2
- When adding a data partition to the boot disk, a minimum offset value of 25000 mebibytes is recommended. The root file system is automatically resized to fill all available space up to the specified offset. If no offset value is specified, or if the specified value is smaller than the recommended minimum, the resulting root file system will be too small, and future reinstalls of RHCOS might overwrite the beginning of the data partition.
- 3
- The size of the data partition in mebibytes.
- 4
- Theprjquotamount option must be enabled for filesystems used for container storage.
 Note- When creating a separate - /varpartition, you cannot use different instance types for compute nodes, if the different instance types do not have the same device name.
- Create a manifest from the Butane config and save it to the - clusterconfig/openshiftdirectory. For example, run the following command:- butane $HOME/clusterconfig/98-var-partition.bu -o $HOME/clusterconfig/openshift/98-var-partition.yaml - $ butane $HOME/clusterconfig/98-var-partition.bu -o $HOME/clusterconfig/openshift/98-var-partition.yaml- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Create the Ignition config files: - openshift-install create ignition-configs --dir <installation_directory> - $ openshift-install create ignition-configs --dir <installation_directory>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- For<installation_directory>, specify the same installation directory.
 - Ignition config files are created for the bootstrap, control plane, and compute nodes in the installation directory: - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - The files in the - <installation_directory>/manifestand- <installation_directory>/openshiftdirectories are wrapped into the Ignition config files, including the file that contains the- 98-var-partitioncustom- MachineConfigobject.
Next steps
- You can apply the custom disk partitioning by referencing the Ignition config files during the RHCOS installations.
16.1.11.3.2.2. Retaining existing partitions
								For an ISO installation, you can add options to the coreos-installer command that cause the installer to maintain one or more existing partitions. For a PXE installation, you can add coreos.inst.* options to the APPEND parameter to preserve partitions.
							
Saved partitions might be data partitions from an existing OpenShift Container Platform system. You can identify the disk partitions you want to keep either by partition label or by number.
If you save existing partitions, and those partitions do not leave enough space for RHCOS, the installation will fail without damaging the saved partitions.
Retaining existing partitions during an ISO installation
									This example preserves any partition in which the partition label begins with data (data*):
								
coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partlabel 'data*' /dev/sda
# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partlabel 'data*' /dev/sda
								The following example illustrates running the coreos-installer in a way that preserves the sixth (6) partition on the disk:
							
coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partindex 6 /dev/sda
# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign \
        --save-partindex 6 /dev/sdaThis example preserves partitions 5 and higher:
coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign
# coreos-installer install --ignition-url http://10.0.2.2:8080/user.ign
        --save-partindex 5- /dev/sda
								In the previous examples where partition saving is used, coreos-installer recreates the partition immediately.
							
Retaining existing partitions during a PXE installation
									This APPEND option preserves any partition in which the partition label begins with 'data' ('data*'):
								
coreos.inst.save_partlabel=data*
coreos.inst.save_partlabel=data*
								This APPEND option preserves partitions 5 and higher:
							
coreos.inst.save_partindex=5-
coreos.inst.save_partindex=5-
								This APPEND option preserves partition 6:
							
coreos.inst.save_partindex=6
coreos.inst.save_partindex=616.1.11.3.3. Identifying Ignition configs
When doing an RHCOS manual installation, there are two types of Ignition configs that you can provide, with different reasons for providing each one:
- Permanent install Ignition config: Every manual RHCOS installation needs to pass one of the Ignition config files generated by - openshift-installer, such as- bootstrap.ign,- master.ignand- worker.ign, to carry out the installation.Important- It is not recommended to modify these Ignition config files directly. You can update the manifest files that are wrapped into the Ignition config files, as outlined in examples in the preceding sections. - For PXE installations, you pass the Ignition configs on the - APPENDline using the- coreos.inst.ignition_url=option. For ISO installations, after the ISO boots to the shell prompt, you identify the Ignition config on the- coreos-installercommand line with the- --ignition-url=option. In both cases, only HTTP and HTTPS protocols are supported.
- Live install Ignition config: This type must be created manually and should be avoided if possible, as it is not supported by Red Hat. With this method, the Ignition config passes to the live install medium, runs immediately upon booting, and performs setup tasks before and/or after the RHCOS system installs to disk. This method should only be used for performing tasks that must be done once and not applied again later, such as with advanced partitioning that cannot be done using a machine config. - For PXE or ISO boots, you can create the Ignition config and - APPENDthe- ignition.config.url=option to identify the location of the Ignition config. You also need to append- ignition.firstboot ignition.platform.id=metalor the- ignition.config.urloption will be ignored.
16.1.11.3.3.1. Embedding a live install Ignition config in the RHCOS ISO
You can embed a live install Ignition config directly in an RHCOS ISO image. When the ISO image is booted, the embedded config will be applied automatically.
Procedure
- 
										Download the coreos-installerbinary from the following image mirror page: https://mirror.openshift.com/pub/openshift-v4/clients/coreos-installer/latest/.
- Retrieve the RHCOS ISO image and the Ignition config file, and copy them into an accessible directory, such as - /mnt:- cp rhcos-<version>-live.x86_64.iso bootstrap.ign /mnt/ chmod 644 /mnt/rhcos-<version>-live.x86_64.iso - # cp rhcos-<version>-live.x86_64.iso bootstrap.ign /mnt/ # chmod 644 /mnt/rhcos-<version>-live.x86_64.iso- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Run the following command to embed the Ignition config into the ISO: - ./coreos-installer iso ignition embed -i /mnt/bootstrap.ign \ /mnt/rhcos-<version>-live.x86_64.iso- # ./coreos-installer iso ignition embed -i /mnt/bootstrap.ign \ /mnt/rhcos-<version>-live.x86_64.iso- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - You can now use that ISO to install RHCOS using the specified live install Ignition config. Important- Using - coreos-installer iso ignition embedto embed a file generated by- openshift-installer, such as- bootstrap.ign,- master.ignand- worker.ign, is unsupported and not recommended.
- To show the contents of the embedded Ignition config and direct it into a file, run: - ./coreos-installer iso ignition show /mnt/rhcos-<version>-live.x86_64.iso > mybootstrap.ign - # ./coreos-installer iso ignition show /mnt/rhcos-<version>-live.x86_64.iso > mybootstrap.ign- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - diff -s bootstrap.ign mybootstrap.ign - # diff -s bootstrap.ign mybootstrap.ign- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Files bootstrap.ign and mybootstrap.ign are identical - Files bootstrap.ign and mybootstrap.ign are identical- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- To remove the Ignition config and return the ISO to its pristine state so you can reuse it, run: - ./coreos-installer iso ignition remove /mnt/rhcos-<version>-live.x86_64.iso - # ./coreos-installer iso ignition remove /mnt/rhcos-<version>-live.x86_64.iso- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - You can now embed another Ignition config into the ISO or use the ISO in its pristine state. 
16.1.11.3.4. Advanced RHCOS installation reference
							This section illustrates the networking configuration and other advanced options that allow you to modify the Red Hat Enterprise Linux CoreOS (RHCOS) manual installation process. The following tables describe the kernel arguments and command-line options you can use with the RHCOS live installer and the coreos-installer command.
						
16.1.11.3.4.1. Networking and bonding options for ISO installations
If you install RHCOS from an ISO image, you can add kernel arguments manually when you boot the image to configure networking for a node. If no networking arguments are specified, DHCP is activated in the initramfs when RHCOS detects that networking is required to fetch the Ignition config file.
									When adding networking arguments manually, you must also add the rd.neednet=1 kernel argument to bring the network up in the initramfs.
								
								The following information provides examples for configuring networking and bonding on your RHCOS nodes for ISO installations. The examples describe how to use the ip=, nameserver=, and bond= kernel arguments.
							
									Ordering is important when adding the kernel arguments: ip=, nameserver=, and then bond=.
								
								The networking options are passed to the dracut tool during system boot. For more information about the networking options supported by dracut, see the dracut.cmdline manual page.
							
The following examples are the networking options for ISO installation.
								To configure an IP address, either use DHCP (ip=dhcp) or set an individual static IP address (ip=<host_ip>). If setting a static IP, you must then identify the DNS server IP address (nameserver=<dns_ip>) on each node. The following 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
- 
										The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none nameserver=4.4.4.41
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
nameserver=4.4.4.41When you use DHCP to configure IP addressing for the RHCOS machines, the machines also obtain the DNS server information through DHCP. For DHCP-based deployments, you can define the DNS server address that is used by the RHCOS nodes through your DHCP server configuration.
You can configure an IP address without assigning a static hostname. If a static hostname is not set by the user, it will be picked up and automatically set by a reverse DNS lookup. To configure an IP address without a static hostname refer to the following example:
- 
										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 DNS server address to 4.4.4.41
- 
										The auto-configuration value to none. No auto-configuration is required when IP networking is configured statically.
ip=10.10.10.2::10.10.10.254:255.255.255.0::enp1s0:none nameserver=4.4.4.41
ip=10.10.10.2::10.10.10.254:255.255.255.0::enp1s0:none
nameserver=4.4.4.41
								You can specify multiple network interfaces by setting 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
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
								Optional: You can configure routes to additional networks by setting an rd.route= value.
							
When you configure one or multiple networks, one default gateway is required. If the additional network gateway is different from the primary network gateway, the default gateway must be the primary network gateway.
- Run the following command to configure the default gateway: - ip=::10.10.10.254:::: - ip=::10.10.10.254::::- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Enter the following command to configure the route for the additional network: - rd.route=20.20.20.0/24:20.20.20.254:enp2s0 - rd.route=20.20.20.0/24:20.20.20.254:enp2s0- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
								You can disable DHCP on a single interface, such as when there are two or more network interfaces and only one interface is being used. In the example, the enp1s0 interface has a static networking configuration and DHCP is disabled for enp2s0, which is not used:
							
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none ip=::::core0.example.com:enp2s0:none
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp1s0:none
ip=::::core0.example.com:enp2s0:noneYou can combine DHCP and static IP configurations on systems with multiple network interfaces, for example:
ip=enp1s0:dhcp ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
ip=enp1s0:dhcp
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0:none
								Optional: You can configure VLANs on individual interfaces by using the vlan= parameter.
							
- To configure a VLAN on a network interface and use a static IP address, run the following command: - ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0.100:none vlan=enp2s0.100:enp2s0 - ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:enp2s0.100:none vlan=enp2s0.100:enp2s0- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- To configure a VLAN on a network interface and to use DHCP, run the following command: - ip=enp2s0.100:dhcp vlan=enp2s0.100:enp2s0 - ip=enp2s0.100:dhcp vlan=enp2s0.100:enp2s0- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
								You can provide multiple DNS servers by adding a nameserver= entry for each server, for example:
							
nameserver=1.1.1.1 nameserver=8.8.8.8
nameserver=1.1.1.1
nameserver=8.8.8.8
								Optional: You can bond multiple network interfaces to a single interface by using the bond= option. Refer to the following 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 bondingto 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 - bond=bond0:em1,em2:mode=active-backup ip=bond0:dhcp- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- 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,fail_over_mac=1 ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
bond=bond0:em1,em2:mode=active-backup,fail_over_mac=1
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0:none
								Always set option fail_over_mac=1 in active-backup mode, to avoid problems when shared OSA/RoCE cards are used.
							
								Optional: You can configure VLANs on bonded interfaces by using the vlan= parameter and to use DHCP, for example:
							
ip=bond0.100:dhcp bond=bond0:em1,em2:mode=active-backup vlan=bond0.100:bond0
ip=bond0.100:dhcp
bond=bond0:em1,em2:mode=active-backup
vlan=bond0.100:bond0Use the following example to configure the bonded interface with a VLAN and to use a static IP address:
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0.100:none bond=bond0:em1,em2:mode=active-backup vlan=bond0.100:bond0
ip=10.10.10.2::10.10.10.254:255.255.255.0:core0.example.com:bond0.100:none
bond=bond0:em1,em2:mode=active-backup
vlan=bond0.100:bond0
								Optional: You can use a network teaming as an alternative to bonding by using the team= parameter:
							
- The syntax for configuring a team interface is: - team=name[:network_interfaces]- name is the team device name ( - team0) and network_interfaces represents a comma-separated list of physical (ethernet) interfaces (- em1, em2).
Teaming is planned to be deprecated when RHCOS switches to an upcoming version of RHEL. For more information, see this Red Hat Knowledgebase Article.
Use the following example to configure a network team:
team=team0:em1,em2 ip=team0:dhcp
team=team0:em1,em2
ip=team0:dhcp16.1.11.4. Updating the bootloader using bootupd
						To update the bootloader by using bootupd, you must either install bootupd on RHCOS machines manually or provide a machine config with the enabled systemd unit. Unlike grubby or other bootloader tools, bootupd does not manage kernel space configuration such as passing kernel arguments.
					
						After you have installed bootupd, you can manage it remotely from the OpenShift Container Platform cluster.
					
							It is recommended that you use bootupd only on bare metal or virtualized hypervisor installations, such as for protection against the BootHole vulnerability.
						
Manual install method
							You can manually install bootupd by using the bootctl command-line tool.
						
- Inspect the system status: - bootupctl status - # bootupctl status- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Component EFI Installed: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64 Update: At latest version - Component EFI Installed: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64 Update: At latest version- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- RHCOS images created without - bootupdinstalled on them require an explicit adoption phase.- If the system status is - Adoptable, perform the adoption:- bootupctl adopt-and-update - # bootupctl adopt-and-update- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Updated: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64 - Updated: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- If an update is available, apply the update so that the changes take effect on the next reboot: - bootupctl update - # bootupctl update- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Updated: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64 - Updated: grub2-efi-x64-1:2.04-31.fc33.x86_64,shim-x64-15-8.x86_64- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
Machine config method
							Another way to enable bootupd is by providing a machine config.
						
- Provide a machine config file with the enabled - systemdunit, as shown in the following example:- Example output - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
16.1.12. Waiting for the bootstrap process to complete
The OpenShift Container Platform bootstrap process begins after the cluster nodes first boot into the persistent RHCOS environment that has been installed to disk. The configuration information provided through the Ignition config files is used to initialize the bootstrap process and install OpenShift Container Platform on the machines. You must wait for the bootstrap process to complete.
Prerequisites
- You have created the Ignition config files for your cluster.
- You have configured suitable network, DNS and load balancing infrastructure.
- You have obtained the installation program and generated the Ignition config files for your cluster.
- You installed RHCOS on your cluster machines and provided the Ignition config files that the OpenShift Container Platform installation program generated.
- 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 \ --log-level=info- $ ./openshift-install --dir <installation_directory> wait-for bootstrap-complete \- 1 - --log-level=info- 2 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443... INFO API v1.21.0 up INFO Waiting up to 30m0s for bootstrapping to complete... INFO It is now safe to remove the bootstrap resources - INFO Waiting up to 30m0s for the Kubernetes API at https://api.test.example.com:6443... INFO API v1.21.0 up INFO Waiting up to 30m0s for bootstrapping to complete... INFO It is now safe to remove the bootstrap resources- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 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 bootstrap machine itself. 
16.1.13. Logging in to the cluster by using the CLI
					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
- You deployed an OpenShift Container Platform cluster.
- 
							You installed the ocCLI.
Procedure
- Export the - kubeadmincredentials:- export KUBECONFIG=<installation_directory>/auth/kubeconfig - $ export KUBECONFIG=<installation_directory>/auth/kubeconfig- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 1
- For<installation_directory>, specify the path to the directory that you stored the installation files in.
 
- Verify you can run - occommands successfully using the exported configuration:- oc whoami - $ oc whoami- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - system:admin - system:admin- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
16.1.14. 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 - $ oc get nodes- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - NAME STATUS ROLES AGE VERSION master-0 Ready master 63m v1.21.0 master-1 Ready master 63m v1.21.0 master-2 Ready master 64m v1.21.0 - NAME STATUS ROLES AGE VERSION master-0 Ready master 63m v1.21.0 master-1 Ready master 63m v1.21.0 master-2 Ready master 64m v1.21.0- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - The output lists all of the machines that you created. Note- The preceding output might not include the compute nodes, also known as worker nodes, until some CSRs are approved. 
- Review the pending CSRs and ensure that you see the client requests with the - Pendingor- Approvedstatus for each machine that you added to the cluster:- oc get csr - $ oc get csr- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - NAME AGE REQUESTOR CONDITION csr-mddf5 20m system:node:master-01.example.com Approved,Issued csr-z5rln 16m system:node:worker-21.example.com Approved,Issued - NAME AGE REQUESTOR CONDITION csr-mddf5 20m system:node:master-01.example.com Approved,Issued csr-z5rln 16m system:node:worker-21.example.com Approved,Issued- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- If the CSRs were not approved, after all of the pending CSRs for the machines you added are in - Pendingstatus, 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. After 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-approverif the Kubelet requests a new certificate with identical parameters.Note- For clusters running on platforms that are not machine API enabled, such as bare metal and other user-provisioned infrastructure, you must implement a method of automatically approving the kubelet serving certificate requests (CSRs). If a request is not approved, then the - oc exec,- oc rsh, and- oc logscommands cannot succeed, because a serving certificate is required when the API server connects to the kubelet. Any operation that contacts the Kubelet endpoint requires this certificate approval to be in place. The method must watch for new CSRs, confirm that the CSR was submitted by the- node-bootstrapperservice account in the- system:nodeor- system:admingroups, and confirm the identity of the node.- To approve them individually, run the following command for each valid CSR: - oc adm certificate approve <csr_name> - $ oc adm certificate approve <csr_name>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 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- $ 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- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- Some Operators might not become available until some CSRs are approved. 
 
- 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 - $ oc get csr- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 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 ... - 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 ...- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- If the remaining CSRs are not approved, and are in the - Pendingstatus, 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> - $ oc adm certificate approve <csr_name>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 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- $ oc get csr -o go-template='{{range .items}}{{if not .status}}{{.metadata.name}}{{"\n"}}{{end}}{{end}}' | xargs oc adm certificate approve- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
 
- After all client and server CSRs have been approved, the machines have the - Readystatus. Verify this by running the following command:- oc get nodes - $ oc get nodes- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- It can take a few minutes after approval of the server CSRs for the machines to transition to the - Readystatus.
Additional information
- For more information on CSRs, see Certificate Signing Requests.
16.1.15. 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 - $ watch -n5 oc get clusteroperators- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Configure the Operators that are not available.
16.1.15.1. Disabling the default OperatorHub sources
Operator catalogs that source content provided by Red Hat and community projects are configured for OperatorHub by default during an OpenShift Container Platform installation. In a restricted network environment, you must disable the default catalogs as a cluster administrator.
Procedure
- Disable the sources for the default catalogs by adding - disableAllDefaultSources: trueto the- OperatorHubobject:- oc patch OperatorHub cluster --type json \ -p '[{"op": "add", "path": "/spec/disableAllDefaultSources", "value": true}]'- $ oc patch OperatorHub cluster --type json \ -p '[{"op": "add", "path": "/spec/disableAllDefaultSources", "value": true}]'- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
						Alternatively, you can use the web console to manage catalog sources. From the Administration 
16.1.15.2. 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.
					
							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."
						
16.1.15.3. 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.
					
16.1.15.3.1. Configuring registry storage for IBM Z
As a cluster administrator, following installation you must configure your registry to use storage.
Prerequisites
- 
									You have access to the cluster as a user with the cluster-adminrole.
- You have a cluster on IBM Z.
- You have provisioned persistent storage for your cluster. Important- OpenShift Container Platform supports - ReadWriteOnceaccess for image registry storage when you have only one replica.- ReadWriteOnceaccess also requires that the registry uses the- Recreaterollout strategy. To deploy an image registry that supports high availability with two or more replicas,- ReadWriteManyaccess is required.
- Must have 100Gi capacity.
Procedure
- To configure your registry to use storage, change the - spec.storage.pvcin the- configs.imageregistry/clusterresource.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 -l docker-registry=default - $ oc get pod -n openshift-image-registry -l docker-registry=default- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - No resourses found in openshift-image-registry namespace - No resourses found in openshift-image-registry namespace- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Note- If you do have a registry pod in your output, you do not need to continue with this procedure. 
- Check the registry configuration: - oc edit configs.imageregistry.operator.openshift.io - $ oc edit configs.imageregistry.operator.openshift.io- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - storage: pvc: claim:- storage: pvc: claim:- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Leave the - claimfield blank to allow the automatic creation of an- image-registry-storagePVC.
- Check the - clusteroperatorstatus:- oc get clusteroperator image-registry - $ oc get clusteroperator image-registry- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE MESSAGE image-registry 4.7 True False False 6h50m - NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE MESSAGE image-registry 4.7 True False False 6h50m- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- Ensure that your registry is set to managed to enable building and pushing of images. - Run: - oc edit configs.imageregistry/cluster - $ oc edit configs.imageregistry/cluster- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Then, change the line - managementState: Removed - managementState: Removed- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - to - managementState: Managed - managementState: Managed- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
 
16.1.15.3.2. 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":{}}}}'- $ oc patch configs.imageregistry.operator.openshift.io cluster --type merge --patch '{"spec":{"storage":{"emptyDir":{}}}}'- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow Warning- Configure this option for only non-production clusters. - If you run this command before the Image Registry Operator initializes its components, the - oc patchcommand fails with the following error:- Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found - Error from server (NotFound): configs.imageregistry.operator.openshift.io "cluster" not found- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Wait a few minutes and run the command again. 
16.1.15.3.3. Configuring block registry storage
							To allow the image registry to use block storage types during upgrades as a cluster administrator, you can use the Recreate rollout strategy.
						
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 - Recreaterollout strategy and runs with only one (- 1) replica:- oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'- $ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- 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.
16.1.16. 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 - $ watch -n5 oc get clusteroperators- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 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 - $ ./openshift-install --dir <installation_directory> wait-for install-complete- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 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... - INFO Waiting up to 30m0s for the cluster to initialize...- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - The command succeeds when the Cluster Version Operator finishes deploying the OpenShift Container Platform cluster from Kubernetes API server. 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-bootstrappercertificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information.
- It is recommended that you use Ignition config files within 12 hours after they are generated because the 24-hour certificate rotates from 16 to 22 hours after the cluster is installed. By using the Ignition config files within 12 hours, you can avoid installation failure if the certificate update runs during installation.
 
- 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 - $ oc get pods --all-namespaces- Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - Example output - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow 
- 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> - $ oc logs <pod_name> -n <namespace>- 1 - Copy to Clipboard Copied! - Toggle word wrap Toggle overflow - 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. 
 
- For an installation with Fibre Channel Protocol (FCP), additional steps are required to enable multipathing. Do not enable multipathing during installation. - See "Enabling multipathing with kernel arguments on RHCOS" in the Post-installation machine configuration tasks documentation for more information. 
16.1.17. Telemetry access for OpenShift Container Platform
In OpenShift Container Platform 4.8, the Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to OpenShift Cluster Manager.
After you confirm that your OpenShift Cluster Manager inventory is correct, either maintained automatically by Telemetry or manually by using OpenShift Cluster Manager, use subscription watch to track your OpenShift Container Platform subscriptions at the account or multi-cluster level.
16.1.18. Next steps
- Customize your cluster.
- If necessary, you can opt out of remote health reporting.
- Set up your registry and configure registry storage.