Connect to PSQL through K8s Ingress-CodePudding

I got my own cluster which has a control-plane and worker. i trying to connect to PostgreSQL in the cluster using psql -h <ingress-url> -p 5432 -U postgres -W, but it occur an error:

psql: error: server closed the connection unexpectedly
        This probably means the server terminated abnormally
        before or while processing the request.

But curl <ingress-url> response like this:

2022-05-27 04:00:50.406 UTC [208] LOG:  invalid length of startup packet

That response mean my request have reached to PostgreSQL Server, but why i cannot connect to my PostgreSQL Server?

Here are my resources:

Ingress:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: preflight
  labels:
    helm.sh/chart: "preflight"
    helm.sh/version: "0.1.0"
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /
    nginx.ingress.kubernetes.io/ssl-redirect: "false"
spec:
  ingressClassName: nginx
  rules:
  - http:
      paths:
      - path: /
        pathType: Exact
        backend:
          service:
            name: preflight
            port:
              number: 5432

Deployment:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: preflight
  labels:
    helm.sh/chart: "preflight"
    helm.sh/version: "0.1.0"
spec:
  replicas: 1
  selector:
    matchLabels:
      helm.sh/chart: "preflight"
      helm.sh/version: "0.1.0"
  template:
    metadata:
      labels:
        helm.sh/chart: "preflight"
        helm.sh/version: "0.1.0"
    spec:
      containers:
      - name: preflight
        image: postgres:14
        env:
        - name: POSTGRES_PASSWORD
          valueFrom:
            configMapKeyRef:
              name: preflight
              key: postgresPassword
        ports:
        - containerPort: 5432

Service:

apiVersion: v1
kind: Service
metadata:
  name: preflight
  labels:
    helm.sh/chart: "preflight"
    helm.sh/version: "0.1.0"
spec:
  type: ClusterIP
  selector:
    helm.sh/chart: "preflight"
    helm.sh/version: "0.1.0"
  ports:
  - port: 5432
    targetPort: 5432

ConfigMap values is a POSTGRES_PASSWORD=postgres.

CodePudding user response：

Nginx ingress controller is an HTTP proxy. You are trying to route PGSQL traffic over HTTP, and that simply can't work.

What you need to do is expose a TCP service through nginx ingress controller. See this page.

In a nutshell, you need to create a configmap like this:

apiVersion: v1
kind: ConfigMap
metadata:
  name: tcp-services
  namespace: <namespace where you deployed ingress controller>
data:
  5432: "default/preflight:5432"

then ensure your nginx ingress controller starts with the --tcp-services-configmap=tcp-services flag.

Finally, ensure the nginx ingress controller Service (the one with type == LoadBalancer) exposes port 5432:

apiVersion: v1
kind: Service
metadata:
  name: ingress-nginx
...
spec:
  type: LoadBalancer
  ports:
    ...
    - name: pgsql
      port: 5432
      targetPort: 5432
      protocol: TCP
...

Please note that your provider's Load Balancer should support TCP backends (most should do, but worth mentioning).

CodePudding user response：

God bless you, whites11! it works!