GKE Persistent Disks - Volume Clone

Step-00: Pre-requisites¶

Verify if GKE Cluster is created

Verify if kubeconfig for kubectl is configured in your local terminal

# Configure kubeconfig for kubectl
gcloud container clusters get-credentials <CLUSTER-NAME> --region <REGION> --project <PROJECT>

# Replace Values CLUSTER-NAME, ZONE, PROJECT
gcloud container clusters get-credentials standard-cluster-private-1 --region us-central1 --project kdaida123

Feature: Compute Engine persistent disk CSI Driver
Verify the Feature Compute Engine persistent disk CSI Driver enabled in GKE Cluster.
This is required for mounting the Google Compute Engine Persistent Disks to Kubernetes Workloads in GKE Cluster.

Step-01: Introduction¶

Understand how to implement cloned Disks in GKE

Step-02: Kubernetes YAML Manifests¶

Project Folder: 01-kube-manifests
No changes to Kubernetes YAML Manifests, same as Section 21-GKE-PD-existing-SC-standard-rwo
01-persistent-volume-claim.yaml
02-UserManagement-ConfigMap.yaml
03-mysql-deployment.yaml
04-mysql-clusterip-service.yaml
05-UserMgmtWebApp-Deployment.yaml
06-UserMgmtWebApp-LoadBalancer-Service.yaml

Step-03: Deploy kube-manifests¶

# Deploy Kubernetes Manifests
kubectl apply -f 01-kube-manifests/

# List Storage Class
kubectl get sc

# List PVC
kubectl get pvc

# List PV
kubectl get pv

# List ConfigMaps
kubectl get configmap

# List Deployments
kubectl get deploy

# List Pods
kubectl get pods

# List Services
kubectl get svc

# Verify Pod Logs
kubectl get pods
kubectl logs -f <USERMGMT-POD-NAME>
kubectl logs -f usermgmt-webapp-6ff7d7d849-7lrg5

Step-04: Verify Persistent Disks¶

Go to Compute Engine -> Storage -> Disks
Search for 4GB Persistent Disk
Observation: Review the below items
Zones: us-central1-c
Type: Balanced persistent disk
In use by: gke-standard-cluster-1-default-pool-db7b638f-j5lk

Step-05: Access Application¶

# List Services
kubectl get svc

# Access Application
http://<ExternalIP-from-get-service-output>
Username: admin101
Password: password101

# Create New User admin102
Username: admin102
Password: password102
First Name: fname102
Last Name: lname102
Email Address: admin102@stacksimplify.com
Social Security Address: ssn102

# Create New User admin103
Username: admin103
Password: password103
First Name: fname103
Last Name: lname103
Email Address: admin103@stacksimplify.com
Social Security Address: ssn103

Step-06: Volume Clone: 01-podpvc-clone.yaml¶

Project Folder: 02-Use-Cloned-Volume-kube-manifests

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: podpvc-clone
spec:
  dataSource:
    name: mysql-pv-claim # the name of the source PersistentVolumeClaim that you created as part of UMS Web App
    kind: PersistentVolumeClaim
  accessModes:
    - ReadWriteOnce
  storageClassName: standard-rwo  # same as the StorageClass of the source PersistentVolumeClaim.   
  resources:
    requests:
      storage: 4Gi # the amount of storage to request, which must be at least the size of the source PersistentVolumeClaim

Step-07: 03-mysql-deployment.yaml¶

- Change-1: Change the `claimName: mysql-pv-claim` to `claimName: podpvc-clone`¶

apiVersion: apps/v1
kind: Deployment
metadata:
  name: mysql2
spec: 
  replicas: 1
  selector:
    matchLabels:
      app: mysql2
  strategy:
    type: Recreate 
  template: 
    metadata: 
      labels: 
        app: mysql2
    spec: 
      containers:
        - name: mysql2
          image: mysql:8.0
          env:
            - name: MYSQL_ROOT_PASSWORD
              value: dbpassword11
          ports:
            - containerPort: 3306
              name: mysql    
          volumeMounts:
            - name: mysql-persistent-storage
              mountPath: /var/lib/mysql    
            - name: usermanagement-dbcreation-script
              mountPath: /docker-entrypoint-initdb.d #https://hub.docker.com/_/mysql Refer Initializing a fresh instance                                         
      volumes: 
        - name: mysql-persistent-storage
          persistentVolumeClaim:
            #claimName: mysql-pv-claim
            claimName: podpvc-clone
        - name: usermanagement-dbcreation-script
          configMap:
            name: usermanagement-dbcreation-script2

Step-08: Kubernetes YAML Manifests¶

Project Folder: 02-Use-Cloned-Volume-kube-manifests
No changes to Kubernetes YAML Manifests, same as Section 21-GKE-PD-existing-SC-standard-rwo
For all the resource names and labels append with 2 (Example: mysql to mysql2, usermgmt-webapp to usermgmt-webapp2)
02-UserManagement-ConfigMap.yaml
03-mysql-deployment.yaml
04-mysql-clusterip-service.yaml
05-UserMgmtWebApp-Deployment.yaml
06-UserMgmtWebApp-LoadBalancer-Service.yaml

Step-09: Deploy kube-manifests¶

# Deploy Kubernetes Manifests
kubectl apply -f 02-Use-Cloned-Volume-kube-manifests/

# List Storage Class
kubectl get sc

# List PVC
kubectl get pvc

# List PV
kubectl get pv

# List ConfigMaps
kubectl get configmap

# List Deployments
kubectl get deploy

# List Pods
kubectl get pods

# List Services
kubectl get svc

# Verify Pod Logs
kubectl get pods
kubectl logs -f <USERMGMT-POD-NAME>
kubectl logs -f usermgmt-webapp2-6ff7d7d849-7lrg5

Step-10: Verify Persistent Disks¶

Go to Compute Engine -> Storage -> Disks
Search for 4GB Persistent Disk
Observation: Review the below items
Type: Balanced persistent disk
In use by: gke-standard-cluster-1-default-pool-db7b638f-j5lk

Step-11: Access Application¶

# List Services
kubectl get svc

# Access Application
http://<ExternalIP-from-get-service-output>
Username: admin101
Password: password101

Observation:
1. You should see both "admin102" and "admin103" users already present.
2. This is because we have used the cloned disk from "01-kube-manifests"

Step-12: Clean-Up¶

# Delete Kubernetes Objects
kubectl delete -f 01-kube-manifests -f 02-Use-Cloned-Volume-kube-manifests

# Reference
https://kubernetes.io/docs/tasks/configure-pod-container/assign-pods-nodes/

# Get Nodes
kubectl get nodes 

# Show Node Labels
kubectl get nodes --show-labels

# Label Node
kubectl label nodes <your-node-name> nodetype=db
kubectl label nodes gke-standard-cluster-pri-default-pool-4f7ab141-p0gz nodetype=db

# Show Node Labels
kubectl get nodes --show-labels

GKE Persistent Disks - Volume Clone

Step-00: Pre-requisites¶

Step-01: Introduction¶

Step-02: Kubernetes YAML Manifests¶

Step-03: Deploy kube-manifests¶

Step-04: Verify Persistent Disks¶

Step-05: Access Application¶

Step-06: Volume Clone: 01-podpvc-clone.yaml¶

Step-07: 03-mysql-deployment.yaml¶

- Change-1: Change the claimName: mysql-pv-claim to claimName: podpvc-clone¶

Step-08: Kubernetes YAML Manifests¶

Step-09: Deploy kube-manifests¶

Step-10: Verify Persistent Disks¶

Step-11: Access Application¶

Step-12: Clean-Up¶

- Change-1: Change the `claimName: mysql-pv-claim` to `claimName: podpvc-clone`¶