Example of ConfigMap, Secret and Volume in pod on Kubernetes

Below kubernetes example include ConfigMap, Secret and Volume, added in pod.

Secret data :

User: admin

pass: pass

# echo "admin" | base64

# echo "pass" | base64

Create ConfigMap and Secret imperative way :

kubectl create configmap cname --from-literal=SERVER_URL=https://go.gl

kubectl create secret generic sname --from-literal=user=YWRtaW4K 

--from-literal=pass=cGFzcwo=

Create folder and sample "index.html" file:

sudo mkdir /mnt/data sudo sh -c "echo 'Hello from Kubernetes storage' > /mnt/data/index.html"

Here, Create yml file for PersistentVolume with 100M storage and StorageClass is manual,

refer below:

apiVersion: v1 kind: PersistentVolume metadata: name: task-pv-volume labels: type: local spec: storageClassName: manual capacity: storage: 100M accessModes: - ReadWriteOnce hostPath: path: "/tmp/data"

# kubectl create -f pv.yml

apiVersion: v1

kind: PersistentVolumeClaim

metadata:

  name: task-pv-claim

spec:

  storageClassName: manual

  accessModes:

    - ReadWriteOnce

  resources:

    requests:

      storage: 100M

# kubectl create -f pvc.yml

Create Pod with ConfigMap, Secret, Volume :

apiVersion: v1

kind: Pod

metadata:

  name: mypod

spec:

  volumes:

  - name: task-pv-storage

    persistentVolumeClaim:

      claimName: task-pv-claim

  - name: mysecret

    secret:

      secretName: sname 

  containers:

    - name: task-pv-container

      image: nginx

      env:

      - name: SERVER_URL_ENV

        valueFrom:

          configMapKeyRef:

            name: cname

            key: SERVER_URL

      volumeMounts:

      - name:  mysecret

        mountPath: "/etc/test"

      - name: task-pv-storage

        mountPath: "/usr/share/nginx/html"

# kubectl create -f pod.yml

Testing :

$ kubectl exec -it mypod sh

# cat /etc/test/* | base64 -d # Test secret

admin

pass

# env | grep SERVER_URL_ENV # check configMap env variable check

SERVER_URL=https://go.gl

# df -h # Check volume mount & also check with "mount" command

Done !