How to deploy a node.js with redis on kubernetes?

I think I figured out a solution (using a Deployment and a Service).

For my deployment, I used two containers (webapp + redis) within one Pod, since it doesn't make sense for a webapp to run without active redis instance, and additionally it connects to redis upon application start. I could be wrong in this reasoning, so feel free to correct me if you think otherwise.

Here's my deployment:

apiVersion: apps/v1kind: Deploymentmetadata:  name: my-app-deploymentspec:  selector:    matchLabels:      app: my-app-deployment  template:    metadata:      labels:        app: my-app-deployment    spec:      containers:      - name: redis        image: redis:latest        ports:        - containerPort: 6379        volumeMounts:        - mountPath: /srv/www          name: redis-storage      - name: my-app        image: my-app:latest        imagePullPolicy: Never        ports:        - containerPort: 8080      volumes:      - name: redis-storage        emptyDir: {}

And here's the Service definition:

apiVersion: v1kind: Servicemetadata:  name: my-app-servicespec:  ports:  - port: 8080    protocol: TCP  type: NodePort  selector:    app: my-app-deployment

I create the deployment with:kubectl create -f deployment.yamlThen, I create the service with kubectl create -f service.yamlI read the IP with minikube ip and extract the port from the output of kubectl describe service my-app-service.

I agree with all of the previous answers. I'm just trying to things more simple by executing a single command.

First, create necessary manifests for redis in a file say redis.yaml and service to expose it outside.

apiVersion: v1kind: Servicemetadata:  name: redis  labels:    app: node-redisspec:  ports:  - name: redis    port: 6379    targetPort: 6379  type: NodePort  selector:    app: node-redis---apiVersion: apps/v1kind: Deploymentmetadata:  name: redisspec:  selector:    matchLabels:      app: node-redis  replicas: 1  template:    metadata:      labels:        app: node-redis    spec:      containers:      - name: redis        image: redis:latest        imagePullPolicy: IfNotPresent        ports:        - containerPort: 6379        # data volume where redis writes data        volumeMounts:        - name: data          mountPath: /data          readOnly: false      volumes:      - name: data        persistentVolumeClaim:          claimName: redis-data---# data volumeapiVersion: v1kind: PersistentVolumeClaimmetadata:  name: redis-data  labels:    app: node-redisspec:  accessModes:  - ReadWriteOnce  resources:    requests:      storage: 100Mi

Next put manifests for your app in another file say my-app.yaml. Here i put the volume field so that you can use the data that stored by redis.

apiVersion: v1kind: Podmetadata:  name: my-app  labels:    app: node-redisspec:  containers:  - name: my-app    image: my-app:latest    ports:    - containerPort: 8080    # data volume from where my-app read data those are written by redis    volumeMounts:    - name: data      mountPath: /data      readOnly: false  volumes:  - name: data    persistentVolumeClaim:      claimName: redis-data

Now we can use the following bash file my-app.sh.

#!/bin/bashkubectl create -f redis.yamlpod_name=$(kubectl get po -l app=node-redis | grep app-with-redis | awk '{print $1}')# check whether redis server is ready or notwhile true; do  pong=$(kubectl exec -it $pod_name -c redis redis-cli ping)  if [[ "$pong" == *"PONG"* ]]; then    echo ok;    break  fidonekubectl create -f my-app.yaml

Just run chmod +x my-app.sh; ./my-app.sh to deploy. To get the url run minikube service redis --url. You can similarly get the url for your app. The only thing is you need a nodePort type service for your app to access it from outside of the cluster.

So, everything is in your hand now.

I would run redis in a separate pod (i.e.: so your web app doesn't take down the redis server if itself crashes).

Here is your redis deployment & service:

deployment.yaml:

apiVersion: apps/v1kind: Deploymentmetadata:  name: redisspec:  selector:    matchLabels:      app: redis  replicas: 1  template:    metadata:      labels:        app: redis    spec:      volumes:        - name: host-sys          hostPath:            path: /sys      initContainers:        - name: disable-thp          image: redis:4.0-alpine          volumeMounts:            - name: host-sys              mountPath: /host-sys          command: ["sh", "-c", "echo never > /host-sys/kernel/mm/transparent_hugepage/enabled"]      containers:      - name: redis        image: redis:4.0-alpine        imagePullPolicy: IfNotPresent        resources:          requests:            cpu: 350m            memory: 1024Mi        ports:        - containerPort: 6379

service.yaml:

apiVersion: v1kind: Servicemetadata:  name: redis  labels:    app: redisspec:  ports:  - port: 6379    name: redis  selector:    app: redis

Since we've exposed a kubernetes Service you can then access your redis instance by hostname, or it's "service name", which is redis.

You can check out my kubernetes redis repository at https://github.com/mateothegreat/k8-byexamples-redis. You can simply run make install if you want the easier route.

Good luck and if you're still stuck please reach out!