gRPC on GKE tutorial: Python client (bookstore_client.py) cannot connect to the API backend in latest version of grc.io/endpointsv2/python-grpc-bookstore-server

[aruns99]

In which file did you encounter the issue?

https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/endpoints/bookstore-grpc/bookstore_server.py

Did you change the file? If so, how?

Overrode the PORT env variable to set it to 8000. Changed https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/endpoints/kubernetes/grpc-bookstore.yaml

image: gcr.io/process-mining-gke/bookstore-grpc-server:latest
env:
- name: PORT
value: "8000"

Describe the issue

This issue is with gRPC on GKE tutorial : https://cloud.google.com/endpoints/docs/grpc/get-started-kubernetes-engine

The python client (bookstore_client.py) can no longer connect to the API backend as the latest docker image build of the API backend (grc.io/endpointsv2/python-grpc-bookstore-server) ends up listening on the port specified by the PORT variable while the proxy (esp) forwards request to port 8000 as specified in the Kubernetes manifest file .

This is likely due to the changes made in https://github.com/GoogleCloudPlatform/python-docs-samples/blob/master/endpoints/bookstore-grpc/bookstore_server.py to make it work in Cloud Run which requires that the server listen on the port specified by the PORT environment.

[tmatsuo]

@aruns99 Thanks for the report.

The change was introduced with #2764

It looks like the code uses 8000 if PORT envvar is not set. Then I think everything should work, but I may miss something.

Adding the author of the PR here.
@nareddyt WDYT?

[tmatsuo]

Maybe in this file, we should use gcr.io/endpointsv2/python-grpc-bookstore-server:2 instead of gcr.io/endpointsv2/python-grpc-bookstore-server:1?

[nareddyt]

For the ESP on GKE tutorial linked by the reported, it asks you to use gcr.io/endpointsv2/python-grpc-bookstore-server:1.

But the issue description above uses gcr.io/process-mining-gke/bookstore-grpc-server:latest. @aruns99, could you clarify where you got this image from? Is this your own backend image?

[nareddyt]

@tmatsuo tag 2 is for some serverless ESP tutorials (cloud run, cloud functions, etc.).

We kept tag 1 as is for the GKE tutorial. gcr.io/endpointsv2/python-grpc-bookstore-server:1 is the correct one for GCE/GKE.

[aruns99]

@nareddyt I generated a new image from source which one would expect to work in either GKE or Cloud Run using gcloud builds submit --tag gcr.io/<PROJECT_ID>/python-grpc-bookstore-server . The fix for GKE is to add PORT=8000 environment variable in endpoints/kubernetes/grpc-bookstore.yaml

[nareddyt]

I see, yes that is a good point. We plan on launching ESPv2 for GKE soon, so I'll update this doc and tutorials with the env var so it works with the latest code.

@tmatsuo can you assign this issue to me? Thanks