How To Move Existing DB Docker Image To Kubernetes

• Requirement:

   We have existing docker images for Oracle DB 18.3 which is running fine. Docker command is:
docker run -itd --name livesql_testdb1  \
-p 1521:1521 -p 5501:5500 \
-e ORACLE_SID=LTEST \
-e ORACLE_PDB=ltestpdb \
-v /u03/LTEST/oradata:/opt/oracle/oradata \
-v /u03/ALTEST/oradata:/u02/app/oracle/oradata \
oracle/database:18.3v2
   We need to move them to kubernetes cluster which is running on the same host.

Solution:

• Label nodes for nodeSelector usages

kubectl label nodes instance-cas-db2 dbhost=livesqlsb
kubectl label nodes instance-cas-mt2 mthost=livesqlsb

• To Create:  kubectl create -f <yaml file>
• Create Peresistent Volumes DB Files storage. yaml is like

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: livesqlsb-pv-volume1
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/u03/LTEST/oradata"
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: livesqlsb-pv-volume2
  labels:
    type: local
spec:
  storageClassName: manual
  capacity:
    storage: 200Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: "/u03/ALTEST/oradata"

• Create Persistent Volumne Claim for DB file storage. yaml is like

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: livesql-pv-claim2
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 200Gi
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: livesql-pv-claim1
spec:
  storageClassName: manual
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi

• Create Service for DB to be accessed by other Apps  in the K8S cluster. yaml is like

apiVersion: v1
kind: Service
metadata:
  labels:
    app: livesqlsb-db
  name: livesqlsb-db-service
  namespace: default
spec:
  clusterIP: None
  ports:
  - port: 1521
    protocol: TCP
    targetPort: 1521
  selector:
    app: livesqlsb-db 

• Create DB Pod in the K8S cluster. yaml is like

apiVersion: v1
kind: Pod
metadata:
  name: livesqlsb-db
  labels:
    app: livesqlsb-db
spec:
  volumes:
    - name: livesqlsb-db-pv-storage1
      persistentVolumeClaim:
       claimName: livesql-pv-claim1
    - name: livesqlsb-db-pv-storage2
      persistentVolumeClaim:
       claimName: livesql-pv-claim2
  containers:
    - image: oracle/database:18.3v2
      name: livesqldb
      ports:
        - containerPort: 1521
          name: livesqldb
      volumeMounts:
        - mountPath: /opt/oracle/oradata
          name: livesqlsb-db-pv-storage1
        - mountPath: /u02/app/oracle/oradata
          name: livesqlsb-db-pv-storage2
      env:
        - name: ORACLE_SID
          value: "LTEST"
        - name: ORACLE_PDB
          value: "ltestpdb"
  nodeSelector:
          dbhost: livesqlsb