Step 1 - Kubernetes Cluster

We already installed minikube for you. To view the nodes in the cluster, run the kubectl get nodes command kubectl get nodes

This command shows all nodes that can be used to host our applications. Now we have only one node, and we can see that it’s status is ready (it is ready to accept applications for deployment).

Step 2 - Redis Master Controller

The first stage of launching the application is to start the Redis Master. A Kubernetes service deployment has, at least, two parts. A replication controllerand a service.

The replication controller defines how many instances should be running, the Docker Image to use, and a name to identify the service. Additional options can be utilized for configuration and discovery. Use the editor above to view the YAML definition.

If Redis were to go down, the replication controller would restart it on an active node.

Create Replication Controller In this example, the YAML defines a redis server called redis-master using the official redis running port 6379.

The kubectl create command takes a YAML definition and instructs the master to start the controller.

kubectl create -f redis-master-controller.yaml

What's running? The above command created a Replication Controller. The Replication

kubectl get rc

All containers described as Pods. A pod is a collection of containers that makes up a particular application, for example Redis. You can view this using kubectl

kubectl get pods

redis-master-contoller.yaml

apiVersion: v1

kind: ReplicationController

metadata:

  name: redis-master1

  labels:

    name: redis-master1

spec:

  replicas: 2

  selector:

    name: redis-master1

  template:

    metadata:

      labels:

        name: redis-master1

    spec:

      containers:

      - name: master

        image: redis:3.0.7-alpine

        ports:

        - containerPort: 6379

Step 3 - Redis Master Service

The second part is a service. A Kubernetes service is a named load balancer that proxies traffic to one or more containers. The proxy works even if the containers are on different nodes.

Services proxy communicate within the cluster and rarely expose ports to an outside interface.

When you launch a service it looks like you cannot connect using curl or netcat unless you start it as part of Kubernetes. The recommended approach is to have a LoadBalancer service to handle external communications.

Create Service The YAML defines the name of the replication controller, redis-master, and the ports which should be proxied.

kubectl create -f redis-master-service.yaml

apiVersion: v1

kind: Service

metadata:

  name: redis-master1

  labels:

    name: redis-master1

spec:

  ports:

    # the port that this service should serve on

  - port: 6379

    targetPort: 6379

  selector:

    name: redis-master1

List & Describe Services

kubectl get services

kubectl describe services redis-master