503 Service Temporarily Unavailable on kubectl apply -f k8s

Question

express-cluster-ip-service.yaml

apiVersion: v1
kind: Service
metadata: 
  name: express-cluster-ip-service
spec:
  type: ClusterIP
  selector:
    component: server
  ports:
    - port: 5000
      targetPort: 5000

express-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: express-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      component: server
  template:
    metadata:
      labels:
        component: server
    spec:
      containers:
        - name: express
          image: simonjames/react-node-docker-kubernetes-app-express
          ports:
            - containerPort: 5000
          env:
            - name: REDIS_HOST
              value: redis-cluster-ip-service
            - name: REDIS_PORT
              value: '6379'
            - name: PGUSER
              value: postgres
            - name: PGHOST
              value: postgres-cluster-ip-service
            - name: PGPORT
              value: '5432'
            - name: PGDATABASE
              value: postgres
            - name: PGPASSWORD
              valueFrom:
                secretKeyRef:
                  name: pgpassword
                  key: PGPASSWORD

react-cluster-ip-service.yaml

apiVersion: v1
kind: Service
metadata:
  name:  react-cluster-ip-service
spec:
  type: ClusterIP
  selector:
    component: web
  ports:
    - port: 3000
      targetPort: 3000

react-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: react-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      component: web
  template:
    metadata:
      labels:
        component: web
    spec:
      containers:
        - name: react
          image: simonjames/react-node-docker-kubernetes-app-react
          ports:
            - containerPort: 3000

ingres-service.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: ingress-service
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
  rules:
    - http:
        paths:
          - path: /?(.*)
            backend:
              serviceName: react-cluster-ip-service
              servicePort: 3000
          - path: /api/?(.*)
            backend:
              serviceName: express-cluster-ip-service
              servicePort: 5000

I am getting a 503 error when I browse the url mapped to my minikube. What may be causing this? Is there any issue with the config. It ran fine when I used docker-compose.yaml. I am using similar configs, so what is the issue here?

Answer 1

A 503 Service Unavailable Error is an HTTP response status code indicating that a server is temporarily unable to handle the request. This may be due to the server being overloaded or down for maintenance.

I performed a test with your deployment yamls but used a different images since I don`t have access to the one that you mention and it all works fine for me. Ingress and services are correctly sending traffic to appropriate pods. If I remove one once of the services I get exact the same error when trying to reach it.

This indicates that this is server connectivity issue and traffic cannot reach your pods due to some configuration, port mismatch or that somewhere in the chain server is down or unreachable.

I suggest you to first check your connectivity with different images and confirm the same results as mine. As second check you may want to look into nginx controller pod:

kubectl logs -n <namespace> <Ingress_nginx_controller_pod_name>