Environment Variables

Environment variables can be defined directly within a Kubernetes Deployment specification:

---

Extended httpd-deployment.yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpd-deployment       
  labels:                      
    app: httpd
spec:
  replicas: 3                 
  selector:
    matchLabels:
      app: httpd              
  template:
    metadata:
      labels:
        app: httpd            
    spec:
      containers:
      - name: httpd
        image: httpd:2.4-trixie
        ports:
        - containerPort: 80
        env:                            # ⚡️ NEW: Environment variables section ⚡️
        - name: GEST                    # 🔑 KEY
          value: "Georg Strassberger"   # 💬 VALUE

Logging into a container

To connect to a running container within the cluster, use the following command:

kubectl exec -it <pod-name> -- /bin/bash

Before doing that, list all currently running pods to find the correct pod name:

kubectl get pods -o wide

Example output:

NAME                                READY   STATUS    RESTARTS   AGE     IP           NODE      NOMINATED NODE   READINESS GATES
httpd-deployment-57d699fd7b-2kmcv   1/1     Running   0          2m10s   10.42.1.23   raspi     <none>           <none>
httpd-deployment-57d699fd7b-555kt   1/1     Running   0          2m17s   10.42.1.22   raspi     <none>           <none>
httpd-deployment-57d699fd7b-mv5td   1/1     Running   0          2m14s   10.42.0.42   fujitsu   <none>           <none>
nginx-deployment-664fcb7fb8-n5ssw   1/1     Running   0          5d19h   10.42.0.16   fujitsu   <none>           <none>
nginx-deployment-664fcb7fb8-ww42v   1/1     Running   0          5d19h   10.42.1.10   raspi     <none>           <none>

The variable is present in all containers. Once inside the container, you can verify that your environment variable was set correctly by running:

root@httpd-deployment-57d699fd7b-2kmcv:/usr/local/apache2# echo $GEST #env -name:GEST
Georg Strassberger

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