Cannot get peer pid for gRPC Go client running in Docker container

[msn_1946]

I have a gRPC Go client running in a Docker container sending a request to a gRPC server over Unix domain socket. On the server I am trying to get the peer PID for the client so I can verify it before processing the request. However, the peer PID is always 0 for the client when it runs within the docker container. I am able to see a peer PID when the client is run outside the container. Here is the stackoverflow link that shows the code snippet:

 https://stackoverflow.com/questions/66142511/cannot-get-peer-pid-for-grpc-go-client-running-in-docker-container