If you are not familiar with the oc command, refer to OpenShift - Getting Started with the oc command.

There are different ways to configure a container with environment variables.

• In a deployment YAML file (this article)
• Using Config Map
• Using Secrets

The oc set env command can be used to create environment variables for a deployment. You could also update a replica set, but this is kind of uncommon, and results in the creation of a new replica set that contains the environment variable, and the pods associated with the replica set will not have the environment variable.

~]$ oc set env deployment my-deployment my-environment-variable="Hello World"
deployment.apps/my-deployment updated

The oc set env command simply updates the deployments template YAML file to have the environment variable, so you could just as well use the oc edit command to update a deployments template YAML file to have the environment variable.

spec:
  containers:
  - name: my-app
    env:
    - name: my-environment-variable
      value: Hello World

A new pod should immediately be created after the oc edit or oc set env commands have been issued, which can be seen with the AGE of the oc get pods command.

~]# oc get pods
NAME            READY   STATUS     RESTARTS  AGE
my-pod-276pc    1/1     Running    0         22s

And the oc describe pod command can be used to see that the pod is now has the environment variable.

~]$ oc describe pod my-pod-276pc
Containers:
  my-container:
    Environment:
      my-environment-variable:  Hello World

The oc set env command with the --list option can be used the list the environment variables associate with the deployment.

~]$ oc set env deployment my-deployment --list
my-environment-variable=Hello World

And the pod.

~]$ oc set env pod my-pod-276pc --list
my-environment-variable=Hello World

And the replica set.

~]$ oc set env replicaset my-deployment-5755cd7b85 --list
my-environment-variable=Hello World

Also, the oc exec command and the env or printenv command can be used to see if the "my_secret" variable contains a value of "Hello" in the container.

~]$ oc exec/my-pod-276pc -- env
my-environment-variable=Hello World