trying to open Postgres port 5432 so it can be accessible from my local machine. the port is only open from kubernetes pods.

127.0.0.1:5432 <====> kubernetes-pod <=====> Postgres Server

basically I want to make port 5432 accessible via my local machine, the port is only accessible from kubernetes-pod. how do I do that.

I tried which I think this would work if postgres server is running on the same pod which is not in my case:

kubectl port-forward pod-5bf5c7df9b-xcjsf 5433:5432

Note: The PostgreSQL server runs as standalone db server and only the pod can access the port and I want to access the PostgreSQL db port from my local machine .

CodePudding user response：

Try this: kubectl port-forward -n <namespace-name> pod/pod-5bf5c7df9b-xcjsf 5432:5432

Note the differences:

1. Namespace needs to be specified if not default
2. I usually prefix the pod name with pod/
3. The local port 5432 connects to the k8s cluster on port 5432

In addition, it's best practice to port-forward to the service instead of the pod. For example: kubectl port-forward -n namespace svc/service-name 5432:5432 since pod names change but the service name does NOT. And, remember that the service port is usually 5432 but the pod may not listen on that port.

I hope this helps. I work for CodeZero and we allow you to easily connect with cluster resources with our teleport feature. Check it out at https://codezero.io

You can also use CodeZero CLI (czctl) to teleport into the cluster and then you can access kubernetes resources locally:

czctl start
czctl namespace teleport <namespace-name>

Then, as long as you have a Service in the cluster pointing to Postgres, you can access that service as if it's running locally on your computer. For example:

Create a Service called my-postgres-db which points to your Postgress Pod/Deployment/ReplicaSet pods. Then you can connect using

psql -h my-postgres-db ...

CodePudding user response：

The easiest and best way to accomplish this is using socat in a pod.

You can use the alpine/socat container image to create the pod. Then use port-forward into this pod which will forward the connections to the target db.

Here are the steps:

1. Create a file my-postgresql-socat.yaml:

apiVersion: v1
kind: Pod
metadata:
  name: my-postgresql-socat
  labels:
    name: my-postgresql-socat
spec:
  containers:
  - name: my-postgresql-socat
    image: alpine/socat
    command: ["socat", "-dd", "tcp4-listen:5432,fork,reuseaddr", "tcp4:my-postgresql-host:5432"]
    resources:
      limits:
        memory: "64Mi"
        cpu: "50m"
    ports:
      - containerPort: 5432

2. Create a pod with

kubectl apply -f my-postgresql-socat.yaml

3. Run a local port-forward:

oc port-forward my-postgresql-socat 5432:5432

You can access your database now via localhost:5432

4. When finished, delete the pod:

kubectl delete pod my-postgresql-socat