> ## Documentation Index > Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt > Use this file to discover all available pages before exploring further. # Solution ConfigMaps Optional > This article provides a step-by-step solution for managing ConfigMaps and environment variables in Kubernetes pods. Hi, I'm Sanjeev, one of the co-instructors for this course. In this lesson, we will walk through the solution for the ConfigMap section of the assignment in a step-by-step manner. ───────────────────────────── ## 1. Determining the Number of Pods Begin by checking how many pods are currently running in your system. Execute the following command: ```bash theme={null} controlplane ~ ➜ kubectl get pods NAME READY STATUS RESTARTS AGE webapp-color 1/1 Running 0 54s controlplane ~ ➜ ``` This confirms that there is one active pod, named **webapp-color**. ───────────────────────────── ## 2. Identifying the Environment Variable in the Pod Next, determine which environment variable is configured in the container by describing the pod: ```bash theme={null} kubectl describe pod webapp-color ``` Search for the **Environment** section in the output. An example excerpt might look like: ```plaintext theme={null} IP: 10.42.0.9 Containers: webapp-color: Container ID: containerd://750b751f5351c7edbaaaaf33e77d8f9709ed85ea4862914bbe4d79c1254b54fb7 Image: kodekloud/webapp-color Image ID: docker.io/kodekloud/webapp-color@sha256:99c3821ea49b89c7a22d3eebab5c2e1ec651452e7675af2434850 Port: Host Port: State: Running Started: Wed, 27 Jul 2022 05:21:49 +0000 Ready: True Restart Count: 0 Environment: APP_COLOR: pink Mounts: /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-rs7nh (ro) ``` From the **Environment** section, note that the variable **APP\_COLOR** is set (ensure you select the correct one if multiple similar names are present). ───────────────────────────── ## 3. Verifying the Environment Variable Value Verify the value of the **APP\_COLOR** variable. The output above indicates that its value is **pink**. ───────────────────────────── ## 4. Viewing the Web Application Click on the web app color tab to open the application in your browser. When the page loads, you should see the application displaying the color corresponding to the **APP\_COLOR** value (in this case, pink). Once confirmed, click **OK** to proceed. ![The image shows a KodeKloud practice test interface for Kubernetes, with a terminal and a question about setting an environment variable name in a pod container.](https://kodekloud.com/kk-media/image/upload/v1752871156/notes-assets/images/Certified-Kubernetes-Application-Developer-CKAD-Solution-ConfigMaps-Optional/frame_30.jpg) ───────────────────────────── ## 5. Updating the Environment Variable for a Green Background The next task is to update the pod configuration so that the background changes to green. This involves deleting and recreating the pod with the necessary modification while keeping the pod name unchanged. ### 5.1 Exporting the Current Pod YAML First, verify the pod again: ```bash theme={null} controlplane ~ ➜ kubectl get pods NAME READY STATUS RESTARTS AGE webapp-color 1/1 Running 0 8m40s ``` Then, export the pod configuration to a file: ```bash theme={null} kubectl get pod webapp-color -o yaml > pod.yaml ``` ### 5.2 Deleting the Current Pod Remove the running pod to make way for the updated configuration: ```bash theme={null} kubectl delete pod webapp-color pod "webapp-color" deleted ``` ### 5.3 Modifying and Applying the Pod Configuration Open the exported **pod.yaml** file in your favorite text editor, such as using `vi`: ```bash theme={null} vi pod.yaml ``` Locate the **env** section under the container definition and change the value of **APP\_COLOR** from **pink** to **green**. Save your modifications. Apply the updated configuration: ```bash theme={null} kubectl apply -f pod.yaml ``` Finally, verify that the pod is running and that the background has changed to green. ![The image shows a KodeKloud practice test interface for Kubernetes, instructing to update a pod's environment variable to display a green background.](https://kodekloud.com/kk-media/image/upload/v1752871157/notes-assets/images/Certified-Kubernetes-Application-Developer-CKAD-Solution-ConfigMaps-Optional/frame_120.jpg) ───────────────────────────── ## 6. Listing ConfigMaps in the Default Namespace To determine how many ConfigMaps are available in the default namespace, run: ```bash theme={null} kubectl get cm ``` The expected output is: ```bash theme={null} NAME DATA AGE kube-root-ca.crt 1 20m db-config 3 50s ``` This output shows there are two ConfigMaps. ───────────────────────────── ## 7. Identifying the Database Host in the ConfigMap Next, identify the database host by inspecting the ConfigMap named **db-config**: ```bash theme={null} kubectl describe cm db-config ``` Within the **Data** section of the output, you might find: ```plaintext theme={null} Data ==== DB_PORT: 3306 DB_HOST: SQL01.example.com DB_NAME: SQL01 ``` Here, **DB\_HOST** is set to **SQL01.example.com**. ───────────────────────────── ## 8. Creating a New ConfigMap for the Webapp-Color Pod Create a new ConfigMap named **webapp-config-map** that defines the **APP\_COLOR** variable with a value of **darkblue** by executing: ```bash theme={null} kubectl create cm webapp-config-map --from-literal=APP_COLOR=darkblue ``` Verify that the new ConfigMap has been created successfully. ───────────────────────────── ## 9. Updating the Pod to Use the New ConfigMap The next step is to update the **webapp-color** pod so that it sources the **APP\_COLOR** environment variable from the new ConfigMap. ### 9.1 Deleting the Existing Pod Delete the current pod with this command: ```bash theme={null} kubectl delete pod webapp-color ``` ### 9.2 Modifying the Pod YAML Update the **pod.yaml** file to reference the ConfigMap rather than using a hard-coded environment variable value. Modify the container specification under the **env** section as follows: ```yaml theme={null} apiVersion: v1 kind: Pod metadata: name: webapp-color labels: name: webapp-color namespace: default spec: containers: - name: webapp-color image: kodekloud/webapp-color imagePullPolicy: Always env: - name: APP_COLOR valueFrom: configMapKeyRef: name: webapp-config-map key: APP_COLOR volumeMounts: - mountPath: /var/run/secrets/kubernetes.io/serviceaccount name: kube-api-access-4bwn readOnly: true # Other pod specifications remain unchanged. ``` Save your changes and apply the updated file: ```bash theme={null} kubectl apply -f pod.yaml ``` After applying the configuration, verify that the pod is running and displays a background color of **darkblue**. ───────────────────────────── ## 10. Verifying the Updated Web Application Finally, open the web app color interface once more and refresh the page. Confirm that the background has successfully changed to **darkblue**. When this change is verified, click **OK** to complete the exercise. ─────────────────────────────\ This concludes the assignment for the ConfigMap lab session. Ensure that you carefully check the environment variable sections in both the pod description and the YAML file when making updates to avoid configuration errors.