Kubernetes Nginx 入口返回 502 Bad Gateway 使用主机文件

Question

After successfully deployed the application (pod looks OK, logs are ok), I created ClusterIP service, then created NGINX Ingress and added host to hosts file. When I try to access posts.com/posts , I get 502 bad gateway error.

ingress-srv.yaml

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: ingress-srv
  annotations:
    nginx.ingress.kubernetes.io/service-upstream: "true"
    nginx.ingress.kubernetes.io/rewrite-target: /
spec:
  rules:
  - host: posts.com
    http:
      paths:
      - path: /posts
        pathType: Prefix
        backend:
          service:
            name: posts-clusterip-srv
            port:
              number: 4000

posts-depl.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: posts-depl
spec:
  replicas: 1
  selector:
    matchLabels:
      app: posts
  template:
    metadata:
      labels:
        app: posts
    spec:
      containers:
        - name: posts
          image: myUser/posts
          resources:
            limits:
              memory: 512Mi
              cpu: "1"
            requests:
              memory: 256Mi
              cpu: "0.2"
          ports:
            - containerPort: 4000
---
apiVersion: v1
kind: Service
metadata:
  name: posts-clusterip-srv
spec:
  selector:
    app: posts
  ports:
    - name: posts
      protocol: TCP
      port: 4000
      targetPort: 4000

##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##
127.0.0.1   localhost
255.255.255.255 broadcasthost
::1 localhost
127.0.0.1   posts.com
# Added by Docker Desktop
# To allow the same kube context to work on the host and the container:
127.0.0.1 kubernetes.docker.internal
# End of section

Dockerfile

FROM node:alpine

WORKDIR /app
COPY package.json ./
RUN npm install
COPY ./ ./

CMD ["npm", "start"]

What can be the problem and where at least I should look for?

Answer 1

I see two problems - try these and let me know if it helps or not:

1. You are missing pathType in your Ingress manifest. It is mandatory to provide this otherwise Kubernetes won't understand whether it is a exact match or a prefix match. Read more over here . (I see that @Sahadat pointed it out rightly but somehow deleted his answer).
2. You are missing port number in your Deployment manifest, it should be like below:

spec:
  containers:
    - name: posts
      image: myuser/posts
      ports:
      - containerPort: 4000

---

UPDATE 1:

One more potential problem could be this entry in your host file - 127.0.0.1 posts.com , delete it and try.