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Preparing to install a cluster on Azure

To prepare for installation of an OKD cluster on Azure, complete the following steps:

Generating a key pair for cluster node SSH access

During an OKD installation, you can provide an SSH public key to the installation program. The key is passed to the Fedora CoreOS (FCOS) 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 FCOS 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.

On clusters running Fedora CoreOS (FCOS), the SSH keys specified in the Ignition config files are written to the /home/core/.ssh/authorized_keys.d/core file. However, the Machine Config Operator manages SSH keys in the /home/core/.ssh/authorized_keys file and configures sshd to ignore the /home/core/.ssh/authorized_keys.d/core file. As a result, newly provisioned OKD nodes are not accessible using SSH until the Machine Config Operator reconciles the machine configs with the authorized_keys file. After you can access the nodes using SSH, you can delete the /home/core/.ssh/authorized_keys.d/core file.
Procedure

  1. 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.

    If you plan to install an OKD cluster that uses the Fedora cryptographic libraries that have been submitted to NIST for FIPS 140-2/140-3 Validation on only the x86_64, ppc64le, and s390x architectures, do not create a key that uses the ed25519 algorithm. Instead, create a key that uses the rsa or ecdsa algorithm.

  2. 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

  3. 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.

    On some distributions, default SSH private key identities such as ~/.ssh/id_rsa and ~/.ssh/id_dsa are managed automatically.

    1. 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

      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.

  4. 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 OKD, provide the SSH public key to the installation program.

Obtaining the installation program

Before you install OKD, download the installation file on the host you are using for installation.

Prerequisites

  • You have a computer that runs Linux or macOS, with 500 MB of local disk space.

Procedure

  1. Download the installation program from https://github.com/openshift/okd/releases.

    • 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 of the files are required to delete the cluster.

    • 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 OKD uninstallation procedures for your specific cloud provider.

  2. 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

  3. Download your installation pull secret from 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 OKD components.

    Using a pull secret from Red Hat OpenShift Cluster Manager is not required. You can use a pull secret for another private registry. Or, if you do not need the cluster to pull images from a private registry, you can use {"auths":{"fake":{"auth":"aWQ6cGFzcwo="}}} as the pull secret when prompted during the installation.

    If you do not use the pull secret from Red Hat OpenShift Cluster Manager:

    • Red Hat Operators are not available.

    • The Telemetry and Insights operators do not send data to Red Hat.

    • Content from the Red Hat Ecosystem Catalog Container images registry, such as image streams and Operators, are not available.

Installing the OpenShift CLI

You can install the OpenShift CLI (oc) to interact with OKD 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 OKD 4. 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

  1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

  2. Download oc.tar.gz.

  3. Unpack the archive:

    $ tar xvf <file>

  4. Place the oc binary in a directory that is on your PATH.

    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

  1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

  2. Download oc.zip.

  3. Unzip the archive with a ZIP program.

  4. Move the oc binary to a directory that is on your PATH.

    To check your PATH, open the command prompt and execute the following command:

    C:\> path
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

  1. Navigate to https://mirror.openshift.com/pub/openshift-v4/clients/oc/latest/ and choose the folder for your operating system and architecture.

  2. Download oc.tar.gz.

  3. Unpack and unzip the archive.

  4. 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

  • Verify your installation by using an oc command:

    $ oc <command>
Additional resources

Preparing an Azure Disk Encryption Set

The OKD installer can use an existing Disk Encryption Set with a user-managed key. To enable this feature, you can create a Disk Encryption Set in Azure and provide the key to the installer.

Procedure

  1. Set the environment variables for the Azure resource group by running the following command:

    $ export RESOURCEGROUP="<resource_group>" \(1)
    LOCATION="<location>" (2)
    1 Specifies the name of the Azure resource group where the Disk Encryption Set and encryption key are to be created. To prevent losing access to your keys when you destroy the cluster, create the Disk Encryption Set in a separate resource group from the one where you install the cluster.
    2 Specifies the Azure location where the resource group is to be created.

  2. Set the environment variables for the Azure Key Vault and Disk Encryption Set by running the following command:

    $ export KEYVAULT_NAME="<keyvault_name>" \(1)
    KEYVAULT_KEY_NAME="<keyvault_key_name>" \(2)
    DISK_ENCRYPTION_SET_NAME="<disk_encryption_set_name>" (3)
    1 Specifies the name of the Azure Key Vault to be created.
    2 Specifies the name of the encryption key to be created.
    3 Specifies the name of the disk encryption set to be created.

  3. Set the environment variable for the ID of your Azure service principal by running the following command:

    $ export CLUSTER_SP_ID="<service_principal_id>" (1)
    1 Specifies the ID of the service principal to be used for installation.

  4. Enable host-level encryption in Azure by running the following command:

    $ az feature register --namespace "Microsoft.Compute" --name "EncryptionAtHost"
    $ az feature show --namespace Microsoft.Compute --name EncryptionAtHost
    $ az provider register -n Microsoft.Compute

  5. Create an Azure resource group to hold the disk encryption set and associated resources by running the following command:

    $ az group create --name $RESOURCEGROUP --location $LOCATION

  6. Create an Azure Key Vault by running the following command:

    $ az keyvault create -n $KEYVAULT_NAME -g $RESOURCEGROUP -l $LOCATION \
    --enable-purge-protection true

  7. Create an encryption key in the key vault by running the following command:

    $ az keyvault key create --vault-name $KEYVAULT_NAME -n $KEYVAULT_KEY_NAME \
    --protection software

  8. Capture the ID of the key vault by running the following command:

    $ KEYVAULT_ID=$(az keyvault show --name $KEYVAULT_NAME --query "[id]" -o tsv)

  9. Capture the key URL in the key vault by running the following command:

    $ KEYVAULT_KEY_URL=$(az keyvault key show --vault-name $KEYVAULT_NAME --name \
    $KEYVAULT_KEY_NAME --query "[key.kid]" -o tsv)

  10. Create a disk encryption set by running the following command:

    $ az disk-encryption-set create -n $DISK_ENCRYPTION_SET_NAME -l $LOCATION -g \
    $RESOURCEGROUP --source-vault $KEYVAULT_ID --key-url $KEYVAULT_KEY_URL

  11. Grant the DiskEncryptionSet resource access to the key vault by running the following commands:

    $ DES_IDENTITY=$(az disk-encryption-set show -n $DISK_ENCRYPTION_SET_NAME -g \
    $RESOURCEGROUP --query "[identity.principalId]" -o tsv)
    $ az keyvault set-policy -n $KEYVAULT_NAME -g $RESOURCEGROUP --object-id \
    $DES_IDENTITY --key-permissions wrapkey unwrapkey get

  12. Grant the Azure service principal permission to read the Disk Encryption Set by running the following commands:

    $ DES_RESOURCE_ID=$(az disk-encryption-set show -n $DISK_ENCRYPTION_SET_NAME -g \
    $RESOURCEGROUP --query "[id]" -o tsv)
    $ az role assignment create --assignee $CLUSTER_SP_ID --role "<reader_role>" \(1)
    --scope $DES_RESOURCE_ID -o jsonc
    1 Specifies an Azure role with read permissions to the disk encryption set. You can use the Owner role or a custom role with the necessary permissions.
Next steps