README.md

Environment Variable

Read about Environment Variables
Imperative commands for env variables
Tips and Tricks

For simulated Practice problems visit KillerCoda.

1. create a pod mypod with image nginx containing two environment variables env1=value1 and env2=value2 .

   Solution

   #generate yaml file
   k run mypod --image=nginx --dry-run=client -o yaml > pod.yaml
   
   #update pod.yaml
   apiVersion: v1
   kind: Pod
   metadata:
     labels:
       run: mypod
     name: mypod
   spec:
     containers:
     - image: nginx
       name: mypod
       resources: {}
       env:
         - name: env1
           value: "value1"
         - name: env2
           value: "value2"
     dnsPolicy: ClusterFirst
     restartPolicy: Always
   
   
   # create the pod
   k create -f pod.yaml

2. write env variables of mypod to mypod-env.txt and check env1=value1 and env2=value2 environment variables are present.

   Solution

   # write env to a file
   k exec mypod -ti -- env > mypod-env.txt
   
   # print env variables
   cat mypod-env.txt
   # env1 and env2 must be present

3. create a nginx pod with image nginx and port is defined by NGINX_PORT to 8080.

   Solution

   # create pod yaml file
   k run nginx --image=nginx --dry-run=client -o yaml > nginx.yaml
   
   # update nginx port to 8080 using env variable
   apiVersion: v1
   kind: Pod
   metadata:
     labels:
       run: nginx
     name: nginx
   spec:
     containers:
     - image: nginx
       name: nginx
       resources: {}
       env:
         - name: NGINX_PORT
           value: "8080"
     dnsPolicy: ClusterFirst
     restartPolicy: Always

4. create a db pod with image mysql, set the following env variables

   • name: MYSQL_ROOT_PASSWORD value: "root_password"
   • name: MYSQL_USER value: "username"
   • name: MYSQL_PASSWORD value: "password"
   • name: MYSQL_DATABASE value: "mydatabase"
   Solution

   # create pod yaml file
   k run db --image=mysql --dry-run=client -o yaml > db.yaml
   
   # set required env variables
   apiVersion: v1
   kind: Pod
   metadata:
     name: db
   spec:
     containers:
     - name: mysql
       image: mysql
       env:
       - name: MYSQL_ROOT_PASSWORD
         value: "root_password"
       - name: MYSQL_USER
         value: "username"
       - name: MYSQL_PASSWORD
         value: "password"
       - name: MYSQL_DATABASE
         value: "mydatabase"