[cka] Env Variables

1. How many PODs exist on the system?
in the current(default) namespace

 

controlplane ~ ➜  k get pods
NAME           READY   STATUS    RESTARTS   AGE
webapp-color   1/1     Running   0          6m9s

 

answer : 1

 

2. What is the environment variable name set on the container in the pod?

controlplane ~ ➜  k describe pod webapp-color 
Name:             webapp-color
Namespace:        default
Priority:         0
Service Account:  default
Node:             controlplane/192.26.255.3
Start Time:       Fri, 05 Jul 2024 13:26:14 +0000
Labels:           name=webapp-color
Annotations:      <none>
Status:           Running
IP:               10.42.0.9
IPs:
  IP:  10.42.0.9
Containers:
  webapp-color:
    Container ID:   containerd://3fa9d4221f9012aa56efdb33146ec5d6a36f997b0a86b967531e064ecd7da0d7
    Image:          kodekloud/webapp-color
    Image ID:       docker.io/kodekloud/webapp-color@sha256:99c3821ea49b89c7a22d3eebab5c2e1ec651452e7675af243485034a72eb1423
    ...
    Environment:
      APP_COLOR:  pink
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-7xljf (ro)
Conditions:

 

answer : APP_COLOR

 

3. What is the value set on the environment variable APP_COLOR on the container in the pod?

answer : pink

 

 

4. View the web application UI by clicking on the Webapp Color Tab above your terminal.
This is located on the right side.

 

 

5. Update the environment variable on the POD to display a green background.
Note: Delete and recreate the POD. Only make the necessary changes. Do not modify the name of the Pod.

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    name: webapp-color
  name: webapp-color
spec:
  containers:
  - image: kodekloud/webapp-color
    name: webapp-color
    resources: {}
    env:
      - name: APP_COLOR
        value: green
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

 

 

6. View the changes to the web application UI by clicking on the Webapp Color Tab above your terminal.
If you already have it open, simply refresh the browser.

 

 

7. How many ConfigMaps exists in the default namespace?

controlplane ~ ➜  k get configmaps 
NAME               DATA   AGE
kube-root-ca.crt   1      30m
db-config          3      21s

 

answer : 2

 

8. Identify the database host from the config map db-config.

 

controlplane ~ ➜  k describe configmaps db-config
Name:         db-config
Namespace:    default
Labels:       <none>
Annotations:  <none>

Data
====
DB_HOST:
----
SQL01.example.com
DB_NAME:
----
SQL01
DB_PORT:
----
3306

BinaryData
====

Events:  <none>

 

answer : SQL01.example.com

 

9. Create a new ConfigMap for the webapp-color POD. Use the spec given below.

 

ConfigMap Name: webapp-config-map
Data: APP_COLOR=darkblue
Data: APP_OTHER=disregard

 

controlplane ~ ➜  k create configmap --help

Examples:
# Create a new config map named my-config with key1=config1 and key2=config2
  kubectl create configmap my-config --from-literal=key1=config1
--from-literal=key2=config2

controlplane ~ ➜  k create configmap webapp-config-map --from-literal=APP_COLOR=darkblue --from-literal=APP_OTHER=disregard

 

 

10. Update the environment variable on the POD to use only the APP_COLOR key from the newly created ConfigMap.
Note: Delete and recreate the POD. Only make the necessary changes. Do not modify the name of the Pod.

 

apiVersion: v1
kind: Pod
metadata:
  creationTimestamp: null
  labels:
    name: webapp-color
  name: webapp-color
spec:
  containers:
  - image: kodekloud/webapp-color
    name: webapp-color
    resources: {}
    env:
      - name: APP_COLOR
        valueFrom:
          configMapKeyRef:
            name: webapp-config-map
            key: APP_COLOR
  dnsPolicy: ClusterFirst
  restartPolicy: Always
status: {}

 

 

11. View the changes to the web application UI by clicking on the Webapp Color Tab above your terminal.
If you already have it open, simply refresh the browser.