Chapter 2. Installing a cluster on vSphere
In OpenShift Container Platform version 4.13, you can install a cluster on your VMware vSphere instance by using installer-provisioned infrastructure.
OpenShift Container Platform supports deploying a cluster to a single VMware vCenter only. Deploying a cluster with machines/machine sets on multiple vCenters is not supported.
2.1. 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.
-
You provisioned persistent storage for your cluster. To deploy a private image registry, your storage must provide
ReadWriteMany
access modes. - The OpenShift Container Platform installer requires access to port 443 on the vCenter and ESXi hosts. You verified that port 443 is accessible.
- If you use a firewall, you confirmed with the administrator that port 443 is accessible. Control plane nodes must be able to reach vCenter and ESXi hosts on port 443 for the installation to succeed.
If you use a firewall, you configured it to allow the sites that your cluster requires access to.
NoteBe sure to also review this site list if you are configuring a proxy.
2.2. Internet access for OpenShift Container Platform
In OpenShift Container Platform 4.13, you require access to the internet to install your cluster.
You must have internet access to:
- Access OpenShift Cluster Manager Hybrid Cloud Console 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 required content and use it to populate a mirror registry with the installation packages. 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.
2.3. VMware vSphere infrastructure requirements
You must install an OpenShift Container Platform cluster on one of the following versions of a VMware vSphere instance that meets the requirements for the components that you use:
- Version 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later
- Version 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later
You can host the VMware vSphere infrastructure on-premise or on a VMware Cloud Verified provider that meets the requirements outlined in the following table:
Virtual environment product | Required version |
---|---|
VMware virtual hardware | 15 or later |
vSphere ESXi hosts | 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later |
vCenter host | 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later |
Component | Minimum supported versions | Description |
---|---|---|
Hypervisor | vSphere 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; vSphere 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later with virtual hardware version 15 | This hypervisor version is the minimum version that Red Hat Enterprise Linux CoreOS (RHCOS) supports. For more information about supported hardware on the latest version of Red Hat Enterprise Linux (RHEL) that is compatible with RHCOS, see Hardware on the Red Hat Customer Portal. |
Storage with in-tree drivers | vSphere 7.0 Update 2 and later; 8.0 Update 1 or later | This plugin creates vSphere storage by using the in-tree storage drivers for vSphere included in OpenShift Container Platform. |
Optional: Networking (NSX-T) | vSphere 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; vSphere 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later | For more information about the compatibility of NSX and OpenShift Container Platform, see the Release Notes section of VMware’s NSX container plugin documentation. |
CPU micro-architecture | x86-64-v2 or higher | OpenShift 4.13 and later are based on RHEL 9.2 host operating system which raised the microarchitecture requirements to x86-64-v2. See the RHEL Microarchitecture requirements documentation. You can verify compatibility by following the procedures outlined in this KCS article. |
You must ensure that the time on your ESXi hosts is synchronized before you install OpenShift Container Platform. See Edit Time Configuration for a Host in the VMware documentation.
Additional resources
- For more information about CSI automatic migration, see "Overview" in VMware vSphere CSI Driver Operator.
2.4. Network connectivity requirements
You must configure the network connectivity between machines to allow OpenShift Container Platform cluster components to communicate.
Review the following details about the required network ports.
Protocol | Port | Description |
---|---|---|
VRRP | N/A | Required for keepalived |
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 |
| virtual extensible LAN (VXLAN) |
| 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 |
2.5. VMware vSphere CSI Driver Operator requirements
To install the vSphere CSI Driver Operator, the following requirements must be met:
- VMware vSphere version: 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later
- vCenter version: 7.0 Update 2 or later, or VMware Cloud Foundation 4.3 or later; 8.0 Update 1 or later, or VMware Cloud Foundation 5.0 or later
- Virtual machines of hardware version 15 or later
- No third-party vSphere CSI driver already installed in the cluster
If a third-party vSphere CSI driver is present in the cluster, OpenShift Container Platform does not overwrite it. The presence of a third-party vSphere CSI driver prevents OpenShift Container Platform from updating to OpenShift Container Platform 4.13 or later.
The VMware vSphere CSI Driver Operator is supported only on clusters deployed with platform: vsphere
in the installation manifest.
Additional resources
- To remove a third-party vSphere CSI driver, see Removing a third-party vSphere CSI Driver.
- To update the hardware version for your vSphere nodes, see Updating hardware on nodes running in vSphere.
2.6. vCenter requirements
Before you install an OpenShift Container Platform cluster on your vCenter that uses infrastructure that the installer provisions, you must prepare your environment.
Required vCenter account privileges
To install an OpenShift Container Platform cluster in a vCenter, the installation program requires access to an account with privileges to read and create the required resources. Using an account that has global administrative privileges is the simplest way to access all of the necessary permissions.
If you cannot use an account with global administrative privileges, you must create roles to grant the privileges necessary for OpenShift Container Platform cluster installation. While most of the privileges are always required, some are required only if you plan for the installation program to provision a folder to contain the OpenShift Container Platform cluster on your vCenter instance, which is the default behavior. You must create or amend vSphere roles for the specified objects to grant the required privileges.
An additional role is required if the installation program is to create a vSphere virtual machine folder.
Example 2.1. Roles and privileges required for installation in vSphere API
vSphere object for role | When required | Required privileges in vSphere API |
---|---|---|
vSphere vCenter | Always |
|
vSphere vCenter Cluster | If VMs will be created in the cluster root |
|
vSphere vCenter Resource Pool | If an existing resource pool is provided |
|
vSphere Datastore | Always |
|
vSphere Port Group | Always |
|
Virtual Machine Folder | Always |
|
vSphere vCenter Datacenter |
If the installation program creates the virtual machine folder. For UPI, |
|
Example 2.2. Roles and privileges required for installation in vCenter graphical user interface (GUI)
vSphere object for role | When required | Required privileges in vCenter GUI |
---|---|---|
vSphere vCenter | Always |
|
vSphere vCenter Cluster | If VMs will be created in the cluster root |
|
vSphere vCenter Resource Pool | If an existing resource pool is provided |
|
vSphere Datastore | Always |
|
vSphere Port Group | Always |
|
Virtual Machine Folder | Always |
|
vSphere vCenter Datacenter |
If the installation program creates the virtual machine folder. For UPI, |
|
Additionally, the user requires some ReadOnly
permissions, and some of the roles require permission to propogate the permissions to child objects. These settings vary depending on whether or not you install the cluster into an existing folder.
Example 2.3. Required permissions and propagation settings
vSphere object | When required | Propagate to children | Permissions required |
---|---|---|---|
vSphere vCenter | Always | False | Listed required privileges |
vSphere vCenter Datacenter | Existing folder | False |
|
Installation program creates the folder | True | Listed required privileges | |
vSphere vCenter Cluster | Existing resource pool | False |
|
VMs in cluster root | True | Listed required privileges | |
vSphere vCenter Datastore | Always | False | Listed required privileges |
vSphere Switch | Always | False |
|
vSphere Port Group | Always | False | Listed required privileges |
vSphere vCenter Virtual Machine Folder | Existing folder | True | Listed required privileges |
vSphere vCenter Resource Pool | Existing resource pool | True | Listed required privileges |
For more information about creating an account with only the required privileges, see vSphere Permissions and User Management Tasks in the vSphere documentation.
Using OpenShift Container Platform with vMotion
If you intend on using vMotion in your vSphere environment, consider the following before installing an OpenShift Container Platform cluster.
- Using Storage vMotion can cause issues and is not supported.
Using VMware compute vMotion to migrate the workloads for both OpenShift Container Platform compute machines and control plane machines is generally supported, where generally implies that you meet all VMware best practices for vMotion.
To help ensure the uptime of your compute and control plane nodes, ensure that you follow the VMware best practices for vMotion, and use VMware anti-affinity rules to improve the availability of OpenShift Container Platform during maintenance or hardware issues.
For more information about vMotion and anti-affinity rules, see the VMware vSphere documentation for vMotion networking requirements and VM anti-affinity rules.
- If you are using VMware vSphere volumes in your pods, migrating a VM across datastores, either manually or through Storage vMotion, causes invalid references within OpenShift Container Platform persistent volume (PV) objects that can result in data loss.
- OpenShift Container Platform does not support selective migration of VMDKs across datastores, using datastore clusters for VM provisioning or for dynamic or static provisioning of PVs, or using a datastore that is part of a datastore cluster for dynamic or static provisioning of PVs.
Cluster resources
When you deploy an OpenShift Container Platform cluster that uses installer-provisioned infrastructure, the installation program must be able to create several resources in your vCenter instance.
A standard OpenShift Container Platform installation creates the following vCenter resources:
- 1 Folder
- 1 Tag category
- 1 Tag
Virtual machines:
- 1 template
- 1 temporary bootstrap node
- 3 control plane nodes
- 3 compute machines
Although these resources use 856 GB of storage, the bootstrap node is destroyed during the cluster installation process. A minimum of 800 GB of storage is required to use a standard cluster.
If you deploy more compute machines, the OpenShift Container Platform cluster will use more storage.
Cluster limits
Available resources vary between clusters. The number of possible clusters within a vCenter is limited primarily by available storage space and any limitations on the number of required resources. Be sure to consider both limitations to the vCenter resources that the cluster creates and the resources that you require to deploy a cluster, such as IP addresses and networks.
Networking requirements
You can use Dynamic Host Configuration Protocol (DHCP) for the network and configure the DHCP server to set persistent IP addresses to machines in your cluster. In the DHCP lease, you must configure the DHCP to use the default gateway.
You do not need to use the DHCP for the network if you want to provision nodes with static IP addresses.
If you are installing to a restricted environment, the VM in your restricted network must have access to vCenter so that it can provision and manage nodes, persistent volume claims (PVCs), and other resources.
Ensure that each OpenShift Container Platform node in the cluster has access to a Network Time Protocol (NTP) server that is discoverable by DHCP. Installation is possible without an NTP server. However, asynchronous server clocks can cause errors, which the NTP server prevents.
Additionally, you must create the following networking resources before you install the OpenShift Container Platform cluster:
Required IP Addresses
An installer-provisioned vSphere installation requires two static IP addresses:
- The API address is used to access the cluster API.
- The Ingress address is used for cluster ingress traffic.
You must provide these IP addresses to the installation program when you install the OpenShift Container Platform cluster.
DNS records
You must create DNS records for two static IP addresses in the appropriate DNS server for the vCenter instance that hosts your OpenShift Container Platform cluster. In each record, <cluster_name>
is the cluster name and <base_domain>
is the cluster base domain that you specify when you install the cluster. A complete DNS record takes the form: <component>.<cluster_name>.<base_domain>.
.
Component | Record | Description |
---|---|---|
API VIP |
| This DNS A/AAAA or CNAME record must point to the load balancer for the control plane machines. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
Ingress VIP |
| A wildcard DNS A/AAAA or CNAME record that points to the load balancer that targets the machines that run the Ingress router pods, which are the worker nodes by default. This record must be resolvable by both clients external to the cluster and from all the nodes within the cluster. |
2.7. 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.
You must use a local key, not one that you configured with platform-specific approaches such as AWS key pairs.
Procedure
If you do not have an 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> 1
- 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~/.ssh
directory.
View the public SSH key:
$ cat <path>/<file_name>.pub
For example, run the following to view the
~/.ssh/id_ed25519.pub
public key:$ cat ~/.ssh/id_ed25519.pub
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 gather
command.NoteOn some distributions, default SSH private key identities such as
~/.ssh/id_rsa
and~/.ssh/id_dsa
are managed automatically.If the
ssh-agent
process is not already running for your local user, start it as a background task:$ eval "$(ssh-agent -s)"
Example output
Agent pid 31874
Add your SSH private key to the
ssh-agent
:$ ssh-add <path>/<file_name> 1
- 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>)
Next steps
- When you install OpenShift Container Platform, provide the SSH public key to the installation program.
2.8. Obtaining the installation program
Before you install OpenShift Container Platform, download the installation file on the host you are using for installation.
Prerequisites
You have a machine that runs Linux, for example Red Hat Enterprise Linux 8, with 500 MB of local disk space.
ImportantIf you attempt to run the installation program on macOS, a known issue related to the
golang
compiler causes the installation of the OpenShift Container Platform cluster to fail. For more information about this issue, see the section named "Known Issues" in the OpenShift Container Platform 4.13 release notes document.
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 that corresponds with your host operating system and architecture, and place the file in the directory where you will store the installation configuration files.
ImportantThe 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.
ImportantDeleting 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
- 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.
2.9. Adding vCenter root CA certificates to your system trust
Because the installation program requires access to your vCenter’s API, you must add your vCenter’s trusted root CA certificates to your system trust before you install an OpenShift Container Platform cluster.
Procedure
-
From the vCenter home page, download the vCenter’s root CA certificates. Click Download trusted root CA certificates in the vSphere Web Services SDK section. The
<vCenter>/certs/download.zip
file downloads. Extract the compressed file that contains the vCenter root CA certificates. The contents of the compressed file resemble the following file structure:
certs ├── lin │ ├── 108f4d17.0 │ ├── 108f4d17.r1 │ ├── 7e757f6a.0 │ ├── 8e4f8471.0 │ └── 8e4f8471.r0 ├── mac │ ├── 108f4d17.0 │ ├── 108f4d17.r1 │ ├── 7e757f6a.0 │ ├── 8e4f8471.0 │ └── 8e4f8471.r0 └── win ├── 108f4d17.0.crt ├── 108f4d17.r1.crl ├── 7e757f6a.0.crt ├── 8e4f8471.0.crt └── 8e4f8471.r0.crl 3 directories, 15 files
Add the files for your operating system to the system trust. For example, on a Fedora operating system, run the following command:
# cp certs/lin/* /etc/pki/ca-trust/source/anchors
Update your system trust. For example, on a Fedora operating system, run the following command:
# update-ca-trust extract
2.10. Deploying the cluster
You can install OpenShift Container Platform on a compatible cloud platform.
You can run the create cluster
command of the installation program only once, during initial installation.
Prerequisites
- Obtain the OpenShift Container Platform installation program and the pull secret for your cluster.
- Verify the cloud provider account on your host has the correct permissions to deploy the cluster. An account with incorrect permissions causes the installation process to fail with an error message that displays the missing permissions.
Optional: Before you create the cluster, configure an external load balancer in place of the default load balancer.
ImportantYou do not need to specify API and Ingress static addresses for your installation program. If you choose this configuration, you must take additional actions to define network targets that accept an IP address from each referenced vSphere subnet. See the section "Configuring an external load balancer".
Procedure
Change to the directory that contains the installation program and initialize the cluster deployment:
$ ./openshift-install create cluster --dir <installation_directory> \ 1 --log-level=info 2
When specifying the directory:
-
Verify that the directory has the
execute
permission. This permission is required to run Terraform binaries under the installation directory. - Use an empty directory. Some installation assets, such as bootstrap X.509 certificates, have short expiration intervals, therefore 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.
-
Verify that the directory has the
Provide values at the prompts:
Optional: Select an SSH key to use to access your cluster machines.
NoteFor production OpenShift Container Platform clusters on which you want to perform installation debugging or disaster recovery, specify an SSH key that your
ssh-agent
process uses.- Select vsphere as the platform to target.
- Specify the name of your vCenter instance.
Specify the user name and password for the vCenter account that has the required permissions to create the cluster.
The installation program connects to your vCenter instance.
ImportantSome VMware vCenter Single Sign-On (SSO) environments with Active Directory (AD) integration might primarily require you to use the traditional login method, which requires the
<domain>\
construct.To ensure that vCenter account permission checks complete properly, consider using the User Principal Name (UPN) login method, such as
<username>@<fully_qualified_domainname>
.- Select the data center in your vCenter instance to connect to.
Select the default vCenter datastore to use.
NoteDatastore and cluster names cannot exceed 60 characters; therefore, ensure the combined string length does not exceed the 60 character limit.
- Select the vCenter cluster to install the OpenShift Container Platform cluster in. The installation program uses the root resource pool of the vSphere cluster as the default resource pool.
- Select the network in the vCenter instance that contains the virtual IP addresses and DNS records that you configured.
- Enter the virtual IP address that you configured for control plane API access.
- Enter the virtual IP address that you configured for cluster ingress.
- Enter the base domain. This base domain must be the same one that you used in the DNS records that you configured.
Enter a descriptive name for your cluster. The cluster name must be the same one that you used in the DNS records that you configured.
NoteDatastore and cluster names cannot exceed 60 characters; therefore, ensure the combined string length does not exceed the 60 character limit.
- Paste the pull secret from the Red Hat OpenShift Cluster Manager.
Verification
When the cluster deployment completes successfully:
-
The terminal displays directions for accessing your cluster, including a link to the web console and credentials for the
kubeadmin
user. -
Credential information also outputs to
<installation_directory>/.openshift_install.log
.
Do not delete the installation program or the files that the installation program creates. Both are required to delete the cluster.
Example output
... INFO Install complete! INFO To access the cluster as the system:admin user when using 'oc', run 'export KUBECONFIG=/home/myuser/install_dir/auth/kubeconfig' INFO Access the OpenShift web-console here: https://console-openshift-console.apps.mycluster.example.com INFO Login to the console with user: "kubeadmin", and password: "password" INFO Time elapsed: 36m22s
-
The Ignition config files that the installation program generates contain certificates that expire after 24 hours, which are then renewed at that time. If the cluster is shut down before renewing the certificates and the cluster is later restarted after the 24 hours have elapsed, the cluster automatically recovers the expired certificates. The exception is that you must manually approve the pending
node-bootstrapper
certificate signing requests (CSRs) to recover kubelet certificates. See the documentation for Recovering from expired control plane certificates for more information. - 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.
2.11. 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 4.13. 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 architecture from the Product Variant drop-down list.
- Select the appropriate version from the Version drop-down list.
- Click Download Now next to the OpenShift v4.13 Linux Client entry and save the file.
Unpack the archive:
$ tar xvf <file>
Place the
oc
binary in a directory that is on yourPATH
.To check your
PATH
, execute the following command:$ echo $PATH
Verification
After you install the OpenShift CLI, it is available using the
oc
command:$ 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 from the Version drop-down list.
- Click Download Now next to the OpenShift v4.13 Windows Client entry and save the file.
- Unzip the archive with a ZIP program.
Move the
oc
binary to a directory that is on yourPATH
.To check your
PATH
, open the command prompt and execute the following command:C:\> path
Verification
After you install the OpenShift CLI, it is available using the
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 from the Version drop-down list.
Click Download Now next to the OpenShift v4.13 macOS Client entry and save the file.
NoteFor macOS arm64, choose the OpenShift v4.13 macOS arm64 Client entry.
- Unpack and unzip the archive.
Move the
oc
binary to a directory on your PATH.To check your
PATH
, open a terminal and execute the following command:$ echo $PATH
Verification
After you install the OpenShift CLI, it is available using the
oc
command:$ oc <command>
2.12. 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
oc
CLI.
Procedure
Export the
kubeadmin
credentials:$ export KUBECONFIG=<installation_directory>/auth/kubeconfig 1
- 1
- For
<installation_directory>
, specify the path to the directory that you stored the installation files in.
Verify you can run
oc
commands successfully using the exported configuration:$ oc whoami
Example output
system:admin
2.13. Creating registry storage
After you install the cluster, you must create storage for the registry Operator.
2.13.1. Image registry removed during installation
On platforms that do not provide shareable object storage, the OpenShift Image Registry Operator bootstraps itself as Removed
. This allows openshift-installer
to complete installations on these platform types.
After installation, you must edit the Image Registry Operator configuration to switch the managementState
from Removed
to Managed
. When this has completed, you must configure storage.
2.13.2. Image registry storage configuration
The Image Registry Operator is not initially available for platforms that do not provide default storage. After installation, you must configure your registry to use storage so that the Registry Operator is made available.
Instructions are shown for configuring a persistent volume, which is required for production clusters. Where applicable, instructions are shown for configuring an empty directory as the storage location, which is available for only non-production clusters.
Additional instructions are provided for allowing the image registry to use block storage types by using the Recreate
rollout strategy during upgrades.
2.13.2.1. Configuring registry storage for VMware vSphere
As a cluster administrator, following installation you must configure your registry to use storage.
Prerequisites
- Cluster administrator permissions.
- A cluster on VMware vSphere.
Persistent storage provisioned for your cluster, such as Red Hat OpenShift Data Foundation.
ImportantOpenShift Container Platform supports
ReadWriteOnce
access for image registry storage when you have only one replica.ReadWriteOnce
access also requires that the registry uses theRecreate
rollout strategy. To deploy an image registry that supports high availability with two or more replicas,ReadWriteMany
access is required.- Must have "100Gi" capacity.
Testing shows issues with using the NFS server on RHEL as storage backend for core services. This includes the OpenShift Container Registry and Quay, Prometheus for monitoring storage, and Elasticsearch for logging storage. Therefore, using RHEL NFS to back PVs used by core services is not recommended.
Other NFS implementations on the marketplace might not have these issues. Contact the individual NFS implementation vendor for more information on any testing that was possibly completed against these OpenShift Container Platform core components.
Procedure
To configure your registry to use storage, change the
spec.storage.pvc
in theconfigs.imageregistry/cluster
resource.NoteWhen you use 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
Example output
No resourses found in openshift-image-registry namespace
NoteIf 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
Example output
storage: pvc: claim: 1
- 1
- Leave the
claim
field blank to allow the automatic creation of animage-registry-storage
persistent volume claim (PVC). The PVC is generated based on the default storage class. However, be aware that the default storage class might provide ReadWriteOnce (RWO) volumes, such as a RADOS Block Device (RBD), which can cause issues when you replicate to more than one replica.
Check the
clusteroperator
status:$ oc get clusteroperator image-registry
Example output
NAME VERSION AVAILABLE PROGRESSING DEGRADED SINCE MESSAGE image-registry 4.7 True False False 6h50m
2.13.2.2. Configuring block registry storage for VMware vSphere
To allow the image registry to use block storage types such as vSphere Virtual Machine Disk (VMDK) during upgrades as a cluster administrator, you can use the Recreate
rollout strategy.
Block storage volumes are supported but not recommended for use with 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
Enter the following command to set the image registry storage as a block storage type, patch the registry so that it uses the
Recreate
rollout strategy, and runs with only1
replica:$ oc patch config.imageregistry.operator.openshift.io/cluster --type=merge -p '{"spec":{"rolloutStrategy":"Recreate","replicas":1}}'
Provision the PV for the block storage device, and create a PVC for that volume. The requested block volume uses the ReadWriteOnce (RWO) access mode.
Create a
pvc.yaml
file with the following contents to define a VMware vSpherePersistentVolumeClaim
object:kind: PersistentVolumeClaim apiVersion: v1 metadata: name: image-registry-storage 1 namespace: openshift-image-registry 2 spec: accessModes: - ReadWriteOnce 3 resources: requests: storage: 100Gi 4
- 1
- A unique name that represents the
PersistentVolumeClaim
object. - 2
- The namespace for the
PersistentVolumeClaim
object, which isopenshift-image-registry
. - 3
- The access mode of the persistent volume claim. With
ReadWriteOnce
, the volume can be mounted with read and write permissions by a single node. - 4
- The size of the persistent volume claim.
Enter the following command to create the
PersistentVolumeClaim
object from the file:$ oc create -f pvc.yaml -n openshift-image-registry
Enter the following command to edit the registry configuration so that it references the correct PVC:
$ oc edit config.imageregistry.operator.openshift.io -o yaml
Example output
storage: pvc: claim: 1
- 1
- By creating a custom PVC, you can leave the
claim
field blank for the default automatic creation of animage-registry-storage
PVC.
For instructions about configuring registry storage so that it references the correct PVC, see Configuring the registry for vSphere.
2.14. Backing up VMware vSphere volumes
OpenShift Container Platform provisions new volumes as independent persistent disks to freely attach and detach the volume on any node in the cluster. As a consequence, it is not possible to back up volumes that use snapshots, or to restore volumes from snapshots. See Snapshot Limitations for more information.
Procedure
To create a backup of persistent volumes:
- Stop the application that is using the persistent volume.
- Clone the persistent volume.
- Restart the application.
- Create a backup of the cloned volume.
- Delete the cloned volume.
2.15. Telemetry access for OpenShift Container Platform
In OpenShift Container Platform 4.13, 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 Hybrid Cloud Console.
After you confirm that your OpenShift Cluster Manager Hybrid Cloud Console 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.
Additional resources
- See About remote health monitoring for more information about the Telemetry service
2.16. Next steps
- Customize your cluster.
- If necessary, you can opt out of remote health reporting.
- Set up your registry and configure registry storage.
- Optional: View the events from the vSphere Problem Detector Operator to determine if the cluster has permission or storage configuration issues.