During local development with Kubernetes/minikube, how should I connect to postgres database running on localhost?

Question

I've set up an application stack running on Google Kubernetes Engine + Google Cloud SQL. When developing locally, I would like my application to connect to a postgres database server running outside the cluster to simulate the production environment.

It seems that the way to do this is by defining an external endpoint as described here: Minikube expose MySQL running on localhost as service

Unfortunately, I am not able to specify "127.0.0.1" as the Endpoint IP address:

kubectl apply -f kubernetes/local/postgres-service.yaml
service "postgres-db" unchanged
The Endpoints "postgres-db" is invalid: subsets[0].addresses[0].ip: 
Invalid value: "127.0.0.1": may not be in the loopback range (127.0.0.0/8)

So I am forced to bind postgres to my actual machine address.

It seems like there MUST be a way to map a port from my localhost into the local kubernetes cluster, but so far I can't find a way to do it.

Anybody know the trick? Or alternatively, can someone suggest an alternative solution which doesn't involve running postgres inside the cluster?

Answer 1

May not be an answer for Minikube, but I ended up here so I share what I did for Kubernetes in Docker for Mac.

I added a service like this for PostgreSQL:

kind: Service
apiVersion: v1
metadata:
  name: postgres
  namespace: default
spec:
  type: ExternalName
  # https://docs.docker.com/docker-for-mac/networking/#use-cases-and-workarounds
  externalName: host.docker.internal
  ports:
    - name: port
      port: 5432

My application was able to connect to the locally running postgres server with this setup using the domain name postgres. The Postgres server can listen to 127.0.0.1 with this setup.