pubsub/pstest: support listening on 0.0.0.0

[larryanz]

Is your feature request related to a problem? Please describe.

Currently, the server in pstest listens on localhost . This limits its accessibility to the local machine only, making it difficult to access the server from outside the container or other machines. In a Dockerized environment, this prevents external clients or other containers from communicating with the server. It would be easier to test and interact with the app if the server could be configured to listen on 0.0.0.0, allowing it to be accessed externally.

Describe the solution you'd like

I would like to see an option like another method to make the server listen on 0.0.0.0 instead of localhost.
For example:

host := "0.0.0.0:3000"
srv := pstest.NewServerWithHost(host)

Describe alternatives you've considered

You may wonder why I need to containerize it? It's because the pubsub-emulator works not stably in our case.

[hongalex]

The code that configures what address to listen on is actually in NewServerWithPort, defined in internal/testutil/server.go. Since this affects more than just Pub/Sub, @codyoss or @quartzmo, wdyt about expanding that test package to support listening on custom addresses?

[codyoss]

@hongalex I think we could accommodate that if needed

[larryanz]

If we decided to support this, do we have any direction? Add a second method for the testutil?
I'm willing to help @hongalex

[hongalex]

Yeah if you want to create a PR for this change, I'd be happy to review it. Adding the method to testutil and wrapping in pubsub fake seems correct.