Practice On Exoscale

Add Services to the VotingApp

In the votingapp directory, create YAML files containing the specifications for the Services of each microservice in the application, according to the table below:

Microservice	File Name	Service Type	Service Details
Vote UI	svc-voteui.yaml	NodePort (31000)	nodePort 31000, port: 80, targetPort: 80
Vote	svc-vote.yaml	ClusterIP	port: 5000, targetPort: 5000
Redis	svc-redis.yaml	ClusterIP	port: 6379, targetPort: 6379
Postgres	svc-db.yaml	ClusterIP	port: 5432, targetPort: 5432
Result	svc-result.yaml	ClusterIP	port: 5000, targetPort: 5000
Result UI	svc-resultui.yaml	NodePort (31001)	nodePort 31001, port: 80, targetPort: 80

Note that it is not necessary to expose the worker Pod with a Service as no Pod needs to connect to it. Instead, it is the worker Pod that connects to redis and db.

For each Pod/Service pair, make sure to properly define a label in the Pod and the corresponding selector in the Service.

Deploy the application defined by these specifications
Access the vote and result interfaces via the NodePort Services
Delete the application

Solution

The Service specifications are as follows:

apiVersion: v1
kind: Service
metadata:
  labels:
    app: vote-ui
  name: vote-ui
spec:
  type: NodePort
  ports:
    - port: 80
      targetPort: 80
      nodePort: 31000
  selector:
    app: vote-ui

apiVersion: v1
kind: Service
metadata:
  labels:
    app: vote
  name: vote
spec:
  ports:
    - port: 5000
      targetPort: 5000
  selector:
    app: vote

apiVersion: v1
kind: Service
metadata:
  labels:
    app: redis
  name: redis
spec:
  type: ClusterIP
  ports:
    - port: 6379
      targetPort: 6379
  selector:
    app: redis

apiVersion: v1
kind: Service
metadata:
  labels:
    app: db
  name: db
spec:
  type: ClusterIP
  ports:
    - port: 5432
      targetPort: 5432
  selector:
    app: db

apiVersion: v1
kind: Service
metadata:
  labels:
    app: result
  name: result
spec:
  ports:
    - port: 5000
      targetPort: 5000
  selector:
    app: result

apiVersion: v1
kind: Service
metadata:
  labels:
    app: result-ui
  name: result-ui
spec:
  type: NodePort
  ports:
    - port: 80
      targetPort: 80
      nodePort: 31001
  selector:
    app: result-ui

Deploy the application with the following command from the votingapp directory:

kubectl apply -f .

The different Pods are now in Running status:

$ kubectl get po,svc
NAME            READY   STATUS    RESTARTS   AGE
pod/db          1/1     Running   0          20s
pod/redis       1/1     Running   0          20s
pod/result      1/1     Running   0          20s
pod/result-ui   1/1     Running   0          20s
pod/vote        1/1     Running   0          20s
pod/vote-ui     1/1     Running   0          21s
pod/worker      1/1     Running   0          20s

NAME                 TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
service/db           ClusterIP   10.100.10.36     <none>        5432/TCP       20s
service/kubernetes   ClusterIP   10.96.0.1        <none>        443/TCP        29m
service/redis        ClusterIP   10.107.167.249   <none>        6379/TCP       20s
service/result       ClusterIP   10.105.157.142   <none>        5000/TCP       20s
service/result-ui    NodePort    10.101.30.191    <none>        80:31001/TCP   20s
service/vote         ClusterIP   10.96.108.192    <none>        5000/TCP       20s
service/vote-ui      NodePort    10.104.203.9     <none>        80:31000/TCP   20s

Using the IP address of one of the cluster nodes, we can access the vote and result interfaces via ports 31000 and 31001 respectively.

Vote

Results

Delete the application with the following command:

kubectl delete -f .