Kubernetes 실습 - Voting App

아래 구조의 서비스를 kubernetes 로 구성해 보자

참고: https://github.com/mmumshad/kubernetes-example-voting-app

Pod(voting-app, result-app, redis, db, worker) yml 작성

voting-app-pod.yml

apiVersion: v1
kind: Pod
metadata:
  name: voting-app-pod
  labels:
    name: voting-app-pod
    app: demo-voting-app
spec:
  containers:
  - name: voting-app
    image: dockersamples/examplevotingapp_vote
    ports:
         - containerPort: 80

result-app-pod.yml

apiVersion: v1
kind: Pod
metadata:
  name: result-app-pod
  labels:
    name: result-app-pod
    app: demo-voting-app
spec:
  containers:
  - name: result-app
    image: dockersamples/examplevotingapp_result
    ports:
     - containerPort: 80

redis-pod.yml

apiVersion: v1
kind: Pod
metadata:
  name: redis-pod
  labels:
    name: redis-pod
    app: demo-voting-app
spec:
  containers:
  - name: redis
    image: redis:latest
    ports:
     - containerPort: 6379

postgres-pod.yml

apiVersion: v1
kind: Pod
metadata:
  name: postgres-pod
  labels:
    name: postgres-pod
    app: demo-voting-app
spec:
  containers:
  - name: postgres
    image: postgres:9.4
    env:
    - name: POSTGRES_USER
      value: "postgres"
    - name:  POSTGRES_PASSWORD
      value: "postgres"
    - name: POSTGRES_HOST_AUTH_METHOD
      value: trust
    ports:
     - containerPort: 5432

worker-app-pod.yml

apiVersion: v1
kind: Pod
metadata:
  name: worker-app-pod
  labels:
    name: worker-app-pod
    app: demo-voting-app
spec:
  containers:
  - name: worker-app
    image: dockersamples/examplevotingapp_worker

Service(voting-app, result-app, redis, postgres) yml 작성

voting-app-service.yml

apiVersion: v1
kind: Service
metadata:
  name: voting-service
  labels:
    name: voting-service
    app: demo-voting-app
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 80
    nodePort: 30004
  selector:
     name: voting-app-pod
     app: demo-voting-app

result-app-service.yml

apiVersion: v1
kind: Service
metadata:
  name: result-service
  labels:
    name: result-service
    app: demo-result-app
spec:
  type: NodePort
  ports:
  - port: 80
    targetPort: 80
    nodePort: 30005
  selector:
     name: result-app-pod
     app: demo-voting-app

redis-service.yml

apiVersion: v1
kind: Service
metadata:
  name: redis
  labels:
    name: redis-service
    app: demo-voting-app
spec:
  ports:
  - port: 6379
    name: redis-something
    targetPort: 6379
  selector:
     name: redis-pod
     app: demo-voting-app

postgres-service.yml

apiVersion: v1
kind: Service
metadata:
  name: db
  labels:
    name: db-service
    app: demo-voting-app
spec:
  ports:
  - port: 5432
    targetPort: 5432
  selector:
     name: postgres-pod
     app: demo-voting-app

Pod, Service 실행하기

kubectl apply -f voting-app-pod.yml
kubectl apply -f voting-app-service.yml
kubectl apply -f redis-pod.yml
kubectl apply -f redis-service.yml
kubectl apply -f postgres-pod.yml
kubectl apply -f postgres-service.yml
kubectl apply -f worker-app-pod.yml
kubectl apply -f result-app-pod.yml
kubectl apply -f result-app-service.yml

App 테스트 하기

voting-app, result-app service 주소 확인

windows 에서 접속해 보기

docker desktop 을 설치해 사용하고 있다면 chrome 에서 http://192.168.49.2:30004, http://192.168.49.2:30005 를 접속해 바로 확인할 수 있다. docker desktop 이 설치가 되어 있지 않다면, wsl2 ubuntu 터미널에서 nginx 설치 (설치시 --with-stream 옵션 필요) 후 proxy 로 연결해 확인할 수 있다. 이때 nginx.conf 에 아래를 추가한다.

stream {
    upstream minikube-voting {
        server 192.168.49.2:30004;
    }

    server {
        listen 30004;
        proxy_pass minikube-voting;
    }

    upstream minikube-result {
        server 192.168.49.2:30005;
    }

    server {
        listen 30005;
        proxy_pass minikube-result;
    }
}

http {
    include       mime.types;
    ...
}

 

이제 windows chrome 브라우저에서 아래처럼 접속할 수 있다.

 

http://localhost:30004 --> http://192.168.49.2:30004

 

http://localhost:30005 --> http://192.168.49.2:30005