This is a diagram that I have used for this lab.

I have used the following link to deploy the PHP Guestbook application with Redis (https://kubernetes.io/docs/tutorials/stateless-application/guestbook/)

Set up an Ubuntu Linux with 2GB RAM and 30GB storage for the Kubernetes host. Allow SSH and HTTP from anywhere to the Linux instance on Security Group.

+ Deployment Redis Database.

Creating the Redis Deployment

#nano redis-leader-deployment.yaml
# SOURCE: https://cloud.google.com/kubernetes-engine/docs/tutorials/guestbook
apiVersion: apps/v1
kind: Deployment
metadata:
  name: redis-leader
  labels:
    app: redis
    role: leader
    tier: backend
spec:
  replicas: 1
  selector:
    matchLabels:
      app: redis
  template:
    metadata:
      labels:
        app: redis
        role: leader
        tier: backend
    spec:
      containers:
      - name: leader
        image: "docker.io/redis:6.0.5"
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort: 6379

#Apply the Redis deployment.

microk8s kubectl apply -f https://k8s.io/examples/application/guestbook/redis-leader-deployment.yaml

# Check Redis Pod is running

microk8s kubectl get pods

# View logs from the Redis leader Pod

microk8s kubectl logs -f deployment/redis-leader

+ Creating the Redis leader Service

#Apply a service to proxy the traffic to the Redis Pod.

#nano redis-leader-service.yaml
# SOURCE: https://cloud.google.com/kubernetes-engine/docs/tutorials/guestbook
apiVersion: v1
kind: Service
metadata:
  name: redis-leader
  labels:
    app: redis
    role: leader
    tier: backend
spec:
  ports:
  - port: 6379
    targetPort: 6379
  selector:
    app: redis
    role: leader
    tier: backend

#Apply the Redis Service with the deployment file.

microk8s kubectl apply -f https://k8s.io/examples/application/guestbook/redis-leader-service.yaml

#verify that the Redis service is running

microk8s kubectl get service

+ Set up Redis followers to make it highly available on a few Redis followers.

#nano redis-follower-deployment.yaml

# SOURCE: https://cloud.google.com/kubernetes-engine/docs/tutorials/guestbook
apiVersion: apps/v1
kind: Deployment
metadata:
  name: redis-follower
  labels:
    app: redis
    role: follower
    tier: backend
spec:
  replicas: 2
  selector:
    matchLabels:
      app: redis
  template:
    metadata:
      labels:
        app: redis
        role: follower
        tier: backend
    spec:
      containers:
      - name: follower
        image: gcr.io/google_samples/gb-redis-follower:v2
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort: 6379

#Apply the Redis Deployment for the redis-follower-deployment.yaml file.

microk8s kubectl apply -f https://k8s.io/examples/application/guestbook/redis-follower-deployment.yaml

# Verify two Redis follower replicas are running. 

microk8s kubectl get pods

+ Creating the Redis follower service.

#nano redis-follower-service.yaml
# SOURCE: https://cloud.google.com/kubernetes-engine/docs/tutorials/guestbook
apiVersion: v1
kind: Service
metadata:
  name: redis-follower
  labels:
    app: redis
    role: follower
    tier: backend
spec:
  ports:
    # the port that this service should serve on
  - port: 6379
  selector:
    app: redis
    role: follower
    tier: backend

#Apply the Redis Service with the deployment file.

microk8s kubectl apply -f https://k8s.io/examples/application/guestbook/redis-follower-service.yaml

# verify that the Redis service is running.

microk8s kubectl get service

+ Set up and Expose the Guestbook Frontend.

#Creating Guestbook Frontend Deployment.

#nano frontend-deployment.yaml

# SOURCE: https://cloud.google.com/kubernetes-engine/docs/tutorials/guestbook
apiVersion: apps/v1
kind: Deployment
metadata:
  name: frontend
spec:
  replicas: 3
  selector:
    matchLabels:
        app: guestbook
        tier: frontend
  template:
    metadata:
      labels:
        app: guestbook
        tier: frontend
    spec:
      containers:
      - name: php-redis
        image: gcr.io/google_samples/gb-frontend:v5
        env:
        - name: GET_HOSTS_FROM
          value: "dns"
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort: 80

#Apply the frontend Deployment file

microk8s kubectl apply -f https://k8s.io/examples/application/guestbook/frontend-deployment.yaml

#Verify three frontend replicas are running.

microk8s kubectl get pods -l app=guestbook -l tier=frontend

+ Creating the Frontend Service.

#nano frontend-service.yaml

# SOURCE: https://cloud.google.com/kubernetes-engine/docs/tutorials/guestbook
apiVersion: v1
kind: Service
metadata:
  name: frontend
  labels:
    app: guestbook
    tier: frontend
spec:
  # if your cluster supports it, uncomment the following to automatically create
  # an external load-balanced IP for the frontend service.
  # type: LoadBalancer
  #type: LoadBalancer
  ports:
    # the port that this service should serve on
  - port: 80
  selector:
    app: guestbook
    tier: frontend

#Apply the frontend Service with the deployment file.

microk8s kubectl apply -f https://k8s.io/examples/application/guestbook/frontend-service.yaml

#Verify three frontend replicas are running.

microk8s kubectl get services

#Check the Frontend Service via LoadBalancer

microk8s kubectl get service frontend

+ Scale the Web Frontend.

microk8s kubectl scale deployment frontend --replicas=5
microk8s kubectl get pods
microk8s kubectl scale deployment frontend --replicas=2
microk8s kubectl get pods

#check frontend service.

+ Expose port 80 via public IP address on Kubernetes host (10.0.0.10). This allows accessing PHP Guestbook from outside.

microk8s kubectl patch svc frontend -n default -p '{"spec": {"type": "LoadBalancer", "externalIPs":["10.0.0.10"]}}'

Access PHP Guestbook from the Internet (http://54.165.173.81).