Envoy grpc_json_transcoder example project

1. Build proto (Optional, I have done this for you but you have to rebuild it if you make changes to the protofile)

   sudo pip install grpcio requests
   cd service
   ./script/gen
   ./script/gen_kv.pb
   cd -
   

2. Build go service (Optional, I have built this for you, feel free to rebuild it if security is a concern for you)

   script/bootstrap
   ./script/build
   

3. Startup docker-compose

   docker-compose up --build
   

4. Do request

   docker-compose exec python /client/client.py set foo bar
   docker-compose exec python /client/client.py get foo
   docker-compose exec python /client/client.py count
   

Explanation

1. Python client sends JSON request to Envoy proxy at port 9001.
2. Envoy proxy convert the JSON request using the provided proto and the grpc_json_transcoder filter.
3. The grpc requests are then forwarded to your microservice cluster which is running a grpc server.

TODO

• Build proto in grpc container instead.
• Guide on deploying to GCP

Caveats

• Using envoy 1.17 as the docker base image. envoyproxy/envoy-dev:latest is recommended.

References

• https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/filters/http/grpc_json_transcoder/v3/transcoder.proto#envoy-v3-api-msg-extensions-filters-http-grpc-json-transcoder-v3-grpcjsontranscoder