gRPC
As of Sourcegraph 5.3.X, gRPC has supplanted REST as our default mode of communication between our microservices for our internal APIs.
searcher fetching an archive from gitserver). Internal APIs don't include things like the GraphQL API that external people can use (including our web interface).
gRPC Tutorial
The internal/grpc/example package in the sourcegraph/sourcegraph monorepo contains a simple, runnable example of a gRPC service and client. It is a good starting point for understanding how to write a gRPC service that covers the following topics:
- All the basic Protobuf types (e.g. primitives, enums, messages, one-ofs, etc.)
- All the basic RPC types (e.g. unary, server streaming, client streaming, bidirectional streaming)
- Error handling (e.g. gRPC errors, wrapping status errors, etc.)
- Implementing a gRPC server (with proper separation of concerns)
- Implementing a gRPC client
- Some known footguns (non-utf8 strings, huge messages, etc.)
- Some Sourcegraph-specific helper packages and patterns (grpc/defaults, grpc/streamio, etc.)
When going through this example for the first time, it is recommended to:
- Read the protobuf definitions in weather/v1/weather.proto to get a sense of the service.
- Run the server and client examples in server/ and client/ (via server/run-server.sh and client/run-client.sh) respectively to see the service in action. You can see a recording of this below:
- Read the implementation of the server and client to get a sense of how things are implemented, and follow the explanatory comments in the code.
