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Installing a cluster on GCP with customizations

In OKD version Latest, you can install a customized cluster on infrastructure that the installation program provisions on Google Cloud Platform (GCP). To customize the installation, you modify parameters in the install-config.yaml file before you install the cluster.

Prerequisites

Internet and Telemetry access for OKD

In OKD Latest, you require access to the internet to install and entitle your cluster. The Telemetry service, which runs by default to provide metrics about cluster health and the success of updates, also requires internet access. If your cluster is connected to the internet, Telemetry runs automatically, and your cluster is registered to the Red Hat OpenShift Cluster Manager. From there, you can allocate entitlements to your cluster.

You must have internet access to:

  • Access the Red Hat OpenShift Cluster Manager page to download the installation program and perform subscription management and entitlement. If the cluster has internet access and you do not disable Telemetry, that service automatically entitles your cluster. If the Telemetry service cannot entitle your cluster, you must manually entitle it on the Cluster registration page.

  • 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.

Generating an SSH private key and adding it to the agent

If you want to perform installation debugging or disaster recovery on your cluster, you must provide an SSH key to both your ssh-agent and to the installation program.

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

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

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

  1. If you do not have an SSH key that is configured for password-less authentication on your computer, create one. For example, on a computer that uses a Linux operating system, run the following command:

    $ ssh-keygen -t rsa -b 4096 -N '' \
    -f <path>/<file_name> (1)
    1 Specify the path and file name, such as ~/.ssh/id_rsa, of the SSH key.

    Running this command generates an SSH key that does not require a password in the location that you specified.

  2. Start the ssh-agent process as a background task:

    $ eval "$(ssh-agent -s)"

Agent pid 31874

  3. Add your SSH private key to the ssh-agent:

    $ ssh-add <path>/<file_name> (1)

Identity added: /home/<you>/<path>/<file_name> (<computer_name>)
    1 Specify the path and file name for your SSH private key, such as ~/.ssh/id_rsa
Next steps

  • When you install OKD, provide the SSH public key to the installation program.

Obtaining the installation program

Before you install OKD, download the installation file on a local computer.

Prerequisites

  • You must install the cluster from a computer that uses Linux or macOS.

  • You need 500 MB of local disk space to download the installation program.

Procedure

  1. Access the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site. If you have a Red Hat account, log in with your credentials. If you do not, create an account.

  2. 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.

    The installation program creates several files on the computer that you use to install your cluster. You must keep both the installation program and the files that the installation program creates after you finish installing the cluster.

  3. Extract the installation program. For example, on a computer that uses a Linux operating system, run the following command:

    $ tar xvf <installation_program>.tar.gz

  4. From the Pull Secret page on the Red Hat OpenShift Cluster Manager site, download your installation pull secret as a .txt file. This pull secret allows you to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OKD components.

Creating the installation configuration file

You can customize your installation of OKD on Google Cloud Platform (GCP).

Prerequisites

  • Obtain the OKD installation program and the pull secret for your cluster.

Procedure

  1. Create the install-config.yaml file.

    1. Run the following command:

      $ ./openshift-install create install-config --dir=<installation_directory> (1)
      1 For <installation_directory>, specify the directory name to store the files that the installation program creates.

      Specify an empty directory. Some installation assets, like bootstrap X.509 certificates have short expiration intervals, so you must not reuse an installation directory. If you want to reuse individual files from another cluster installation, you can copy them into your directory. However, the file names for the installation assets might change between releases. Use caution when copying installation files from an earlier OKD version.

    2. At the prompts, provide the configuration details for your cloud:

      1. Optional: Select an SSH key to use to access your cluster machines.

        For production OKD clusters on which you want to perform installation debugging or disaster recovery on, specify an SSH key that your ssh-agent process uses.

      2. Select gcp as the platform to target.

      3. If you have not configured the service account key for your GCP account on your computer, you must obtain it from GCP and paste the contents of the file or enter the absolute path to the file.

      4. Select the project ID to provision the cluster in. The default value is specified by the service account that you configured.

      5. Select the region to deploy the cluster to.

      6. Select the base domain to deploy the cluster to. The base domain corresponds to the public DNS zone that you created for your cluster.

      7. Enter a descriptive name for your cluster. If you provide a name that is longer than 6 characters, only the first 6 characters will be used in the infrastructure ID that is generated from the cluster name.

      8. Paste the pull secret that you obtained from the Pull Secret page on the Red Hat OpenShift Cluster Manager site.

  2. Modify the install-config.yaml file. You can find more information about the available parameters in the Installation configuration parameters section.

  3. Back up the install-config.yaml file so that you can use it to install multiple clusters.

    The install-config.yaml file is consumed during the installation process. If you want to reuse the file, you must back it up now.

Installation configuration parameters

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

You cannot modify these parameters in the install-config.yaml file after installation.
Table 1. Required parameters
Parameter Description Values

baseDomain

The base domain of your cloud provider. This value is used to create routes to your OKD cluster components. The full DNS name for your cluster is a combination of the baseDomain and metadata.name parameter values that uses the <metadata.name>.<baseDomain> format.

A fully-qualified domain or subdomain name, such as example.com.

controlPlane.platform

The cloud provider to host the control plane machines. This parameter value must match the compute.platform parameter value.

aws, azure, gcp, openstack, or {}

compute.platform

The cloud provider to host the worker machines. This parameter value must match the controlPlane.platform parameter value.

aws, azure, gcp, openstack, or {}

metadata.name

The name of your cluster.

A string that contains uppercase or lowercase letters, such as dev.

platform.<platform>.region

The region to deploy your cluster in.

A valid region for your cloud, such as us-east-1 for AWS, centralus for Azure, or region1 for Red Hat OpenStack Platform (RHOSP).

pullSecret

The pull secret that you obtained from the Pull Secret page on the Red Hat OpenShift Cluster Manager site. You use this pull secret to authenticate with the services that are provided by the included authorities, including Quay.io, which serves the container images for OKD components.

 
{
   "auths":{
      "cloud.openshift.com":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      },
      "quay.io":{
         "auth":"b3Blb=",
         "email":"you@example.com"
      }
   }
}
Table 2. Optional parameters
Parameter Description Values

sshKey

The SSH key to use to access your cluster machines.

For production OKD clusters on which you want to perform installation debugging or disaster recovery on, specify an SSH key that your ssh-agent process uses.

A valid, local public SSH key that you added to the ssh-agent process.

fips

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 OKD runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.

false or true

publish

How to publish the user-facing endpoints of your cluster.

Internal or External. Set publish to Internal to deploy a private cluster, which cannot be accessed from the internet. The default value is External.

compute.hyperthreading

Whether to enable or disable simultaneous multithreading, or hyperthreading, on compute machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

compute.replicas

The number of compute machines, which are also known as worker machines, to provision.

A positive integer greater than or equal to 2. The default value is 3.

controlPlane.hyperthreading

Whether to enable or disable simultaneous multithreading, or hyperthreading, on control plane machines. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance.

Enabled or Disabled

controlPlane.replicas

The number of control plane machines to provision.

A positive integer greater than or equal to 3. The default value is 3.
Table 3. Additional Google Cloud Platform (GCP) parameters
Parameter Description Values

platform.gcp.network

The name of the existing VPC that you want to deploy your cluster to.

String.

platform.gcp.type

The GCP machine type.

The GCP machine type.

platform.gcp.zones

The availability zones where the installation program creates machines for the specified MachinePool.

A list of valid GCP availability zones, such as us-central1-a, in a YAML sequence.

platform.gcp.controlPlaneSubnet

The name of the existing subnet in your VPC that you want to deploy your control plane machines to.

The subnet name.

platform.gcp.computeSubnet

The name of the existing subnet in your VPC that you want to deploy your compute machines to.

The subnet name.

Sample customized install-config.yaml file for GCP

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

This sample YAML file is provided for reference only. You must obtain your install-config.yaml file by using the installation program and modify it.

 
apiVersion: v1
baseDomain: example.com (1)
controlPlane: (2)
  hyperthreading: Enabled  (3) (4)
  name: master
  platform:
    gcp:
      type: n2-standard-4
      zones:
      - us-central1-a
      - us-central1-c
  replicas: 3
compute: (2)
- hyperthreading: Enabled (3)
  name: worker
  platform:
    gcp:
      type: n2-standard-4
      zones:
      - us-central1-a
      - us-central1-c
  replicas: 3
metadata:
  name: test-cluster (1)
networking:
  clusterNetwork:
  - cidr: 10.128.0.0/14
    hostPrefix: 23
  machineNetwork:
  - cidr: 10.0.0.0/16
  networkType: OpenShiftSDN
  serviceNetwork:
  - 172.30.0.0/16
platform:
  gcp:
    ProjectID: openshift-production (1)
    region: us-central1 (1)
pullSecret: '{"auths": ...}' (1)
fips: false (5)
sshKey: ssh-ed25519 AAAA... (6)
1 Required. The installation program prompts you for this value.
2 If you do not provide these parameters and values, the installation program provides the default value.
3 The controlPlane section is a single mapping, but the compute section is a sequence of mappings. To meet the requirements of the different data structures, the first line of the compute section must begin with a hyphen, -, and the first line of the controlPlane section must not. Although both sections currently define a single machine pool, it is possible that future versions of OKD will support defining multiple compute pools during installation. Only one control plane pool is used.
4 Whether to enable or disable simultaneous multithreading, or hyperthreading. By default, simultaneous multithreading is enabled to increase the performance of your machines' cores. You can disable it by setting the parameter value to Disabled. If you disable simultaneous multithreading in some cluster machines, you must disable it in all cluster machines.

If you disable simultaneous multithreading, ensure that your capacity planning accounts for the dramatically decreased machine performance. Use larger machine types, such as n1-standard-8, for your machines if you disable simultaneous multithreading.
5 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 OKD runs on bypass the default Kubernetes cryptography suite and use the cryptography modules that are provided with RHCOS instead.
6 You can optionally provide the sshKey value that you use to access the machines in your cluster.

For production OKD clusters on which you want to perform installation debugging or disaster recovery on, specify an SSH key that your ssh-agent process uses.

Deploy the cluster

You can install OKD on a compatible cloud platform.

You can run the create cluster command of the installation program only once, during initial installation.
Prerequisites

  • Configure an account with the cloud platform that hosts your cluster.

  • Obtain the OKD installation program and the pull secret for your cluster.

Procedure

  1. Remove any existing GCP credentials that do not use the service account key for the GCP account that you configured for your cluster and that are stored in the following locations:

    • The GOOGLE_CREDENTIALS, GOOGLE_CLOUD_KEYFILE_JSON, or GCLOUD_KEYFILE_JSON environment variables

    • The ~/.gcp/osServiceAccount.json file

    • The gcloud cli default credentials

  2. Run the installation program:

    $ ./openshift-install create cluster --dir=<installation_directory> \ (1)
    --log-level=info (2)
    1 For <installation_directory>, specify the location of your customized ./install-config.yaml file.
    2 To view different installation details, specify warn, debug, or error instead of info.

    If the cloud provider account that you configured on your host does not have sufficient permissions to deploy the cluster, the installation process stops, and the missing permissions are displayed.

    When the cluster deployment completes, directions for accessing your cluster, including a link to its web console and credentials for the kubeadmin user, display in your terminal.

    The Ignition config files that the installation program generates contain certificates that expire after 24 hours. You must keep the cluster running for 24 hours in a non-degraded state to ensure that the first certificate rotation has finished.

    You must not delete the installation program or the files that the installation program creates. Both are required to delete the cluster.

  3. Optional: You can reduce the number of permissions for the service account that you used to install the cluster.

    • If you assigned the Owner role to your service account, you can remove that role and replace it with the Viewer role.

    • If you included the Service Account Key Admin role, you can remove it.

Installing the CLI by downloading the binary

You can install the CLI in order to interact with OKD using a command-line interface.

If you installed an earlier version of oc, you cannot use it to complete all of the commands in OKD Latest. Download and install the new version of oc.
Procedure

  1. From the Infrastructure Provider page on the Red Hat OpenShift Cluster Manager site, navigate to the page for your installation type and click Download Command-line Tools.

  2. Click the folder for your operating system and architecture and click the compressed file.

    You can install oc on Linux, Windows, or macOS.

  3. Save the file to your file system.

  4. Extract the compressed file.

  5. Place it in a directory that is on your PATH.

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

$ oc <command>

Logging in to the cluster

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

Prerequisites

  • Deploy an OKD cluster.

  • Install the oc CLI.

Procedure

  1. 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.

  2. Verify you can run oc commands successfully using the exported configuration:

    $ oc whoami
system:admin
Next steps