OpenShift Container Platform

Reference environment variables

When creating pods, you can reference the value of a previously defined environment variable by using the $() syntax. By using this syntax, you can reference variables that you define within a pod configuration elsewhere in that configuration.

If the environment variable reference cannot be resolved, the value will be left as the provided string.

Procedure

Create a pod that references an existing environment variable:

Create a pod.yaml file similar to the following:

apiVersion: v1
kind: Pod
metadata:
  name: dapi-env-test-pod
spec:
  securityContext:
    runAsNonRoot: true
    seccompProfile:
      type: RuntimeDefault
  containers:
    - name: env-test-container
      image: gcr.io/google_containers/busybox
      command: [ "/bin/sh", "-c", "env" ]
      env:
        - name: MY_EXISTING_ENV
          value: my_value
        - name: MY_ENV_VAR_REF_ENV
          value: $(MY_EXISTING_ENV)
      securityContext:
        allowPrivilegeEscalation: false
        capabilities:
          drop: [ALL]
  restartPolicy: Never
# ...

Create the pod from the pod.yaml file by using the following command:
```
$ oc create -f pod.yaml
```

Verification

Check the container’s logs for the MY_ENV_VAR_REF_ENV value by using the following command:
```
$ oc logs -p dapi-env-test-pod
```