How to assign cluster, namespace and pod name in kubernetes yaml file's environment variable

You can get POD_NAME and POD_NAMESPACE passing them as environment variables via fieldRef.

apiVersion: v1kind: Podmetadata:  name: test-envspec:  containers:    - name: test-container      image: my-test-image:latest      env:        - name: MY_NODE_NAME          valueFrom:            fieldRef:              fieldPath: spec.nodeName        - name: MY_POD_NAME          valueFrom:            fieldRef:              fieldPath: metadata.name        - name: MY_POD_NAMESPACE          valueFrom:            fieldRef:              fieldPath: metadata.namespace        - name: MY_POD_IP          valueFrom:            fieldRef:              fieldPath: status.podIP        - name: MY_POD_SERVICE_ACCOUNT          valueFrom:            fieldRef:              fieldPath: spec.serviceAccountName        - name: REFERENCE_EXAMPLE          value: "/$(MY_NODE_NAME)/$(MY_POD_NAMESPACE)/$(MY_POD_NAME)/data.log"  restartPolicy: Never

EDIT: Added example env REFERENCE_EXAMPLE to show how to reference variables. Thanks to this answer for pointing out the $() interpolation.

You can reference supports metadata.name, metadata.namespace, metadata.labels, metadata.annotations, spec.nodeName, spec.serviceAccountName, status.hostIP, status.podIP as mentioned in the documentation here.

However, CLUSTERNAME is not a standard property available. According to this PR #22043, the CLUSTERNAME should be injected to the .metadata field if using GCE.

Otherwise, you'll have to specific the CLUSTERNAME manually in the .metadata field and then use fieldRef to inject it as an environment variable.

Below format helped me, suggested by ewok2030 and Praveen.Only one thing to make sure that the variable should be declared before they are used as JAVA_OPTS.

containers:

   - env:    - name: APPD_NODE_NAME       valueFrom:         fieldRef:          fieldPath: spec.nodeName    - name: APPD_POD_NAMESPACE      valueFrom:        fieldRef:          fieldPath: metadata.namespace    - name: APP_POD_NAME      valueFrom:         fieldRef:          fieldPath: metadata.name    - name: JAVA_OPTS      value: -Xmx712m -Xms556m -Dpdp.logging.level=WARN -Dappdynamics.agent.nodeName=$(APPD_NODE_NAME)-$(APPD_POD_NAMESPACE)-$(APP_POD_NAME)