Red Hat OpenShift for VMware overview

Selection of the target cluster for installation

During deployment and Day 2 operations, you are prompted for the cluster. You can install the service on the management cluster or any workload cluster.

Bastion details

The bastion VM contains an installation directory with the files and tools that are needed to manage and expand the Red Hat OpenShift cluster.

You can log in to the bastion VM by using SSH and the credentials that are provided on the Red Hat OpenShift for VMware service details page. To run commands as the root user, use the command sudo -i.

In addition, most commands for Red Hat OpenShift management must be run from the installation directory. You can change to the installation directory with the command cd /opt/ocpinstall.

Any commands that require the openshift-install, oc, or kubeadmin tools must reference the files that are located in the installation directory by prefixing the command name with ./. For example, ./oc whoami instead of oc whoami.

The Red Hat OpenShift-related files from the bastion include an SSH key, an installation configuration file, command-line tools, and a kubeconfig file. The exact location of the installation configuration directory on the bastion is shown on the service details page.

SSH key

The SSH key on the bastion is installed on all Red Hat OpenShift cluster VMs, which allows SSH login from the bastion into any cluster VM. The full path to the SSH key is displayed on the service details page. For security purposes, it is highly recommended that you generate a new SSH key and update the cluster VMs with the new key. For more information, see Changing the SSH key on the Red Hat OpenShift bastion VM.

When you log in to a cluster VM from the bastion, you must connect as the core user as shown in the following example:

root@bastion# ssh core@control-plane0

High availability

The Red Hat OpenShift VMs are deployed with DRS rules to ensure that they are on physically separate hosts. If a host must be replaced or redeployed, you must adjust the preconfigured DRS rules before you proceed.

Installation configuration files

The installation configuration file install-config.yaml.bak is located in the installation directory on the bastion. The file is a copy of the original install-config.yaml file that was used by the openshift-install program to generate the ignition files. The generated ignition files can also be found in the installation directory on the bastion.

The oc and kubectl command-line tools from the Red Hat OpenShift client software are on the bastion. The installer program, named openshift-install, is used to install Red Hat OpenShift and can also be used to generate fresh ignition files.

The bastion also holds a file that is named auth/kubeconfig, needed for authentication. This file holds the initial kubeadmin credentials that are created during installation. Before you initially use the oc or kubectl tools, you must set the KUBECONFIG environment variable with the path to this file. For example, export KUBECONFIG=auth/kubeconfig.

After that is done, any commands you run will be as the kubeadmin user. You can verify the user account by running the following command:

./oc whoami

After you configure your authentication and any additional users, you no longer need to source this file, and you can log in as the user that you created.

Red Hat subscriptions

The Red Hat OpenShift cluster is associated with the Red Hat account from the pull secret that was provided during installation. To assign subscriptions or manage the cluster, you can view the cluster in the Red Hat portal under Systems or Clusters.