Interface between gRPC API containers and API adapter containers

• Each gRPC API container must provide the following file: /api/main.proto

• The /api directory is a shared Docker volume. It is provided by the gRPC API container and used by the API adapter container. The API adapter container loads the /api/main.proto file to communicate with the gRPC API container.

  • Therefore, the Dockerfile of the gRPC API container must include the statement VOLUME /api.

• The /api/main.proto file is the only required file. Therefore each API adapter must work properly based on this file without any additional metadata.

• The /api directory can optionally contain additional files such as metadata, which may be read and considered by certain API adapters.

• The /api/main.proto file must follow the Protocol Buffers specification version 3 (proto3). Each API adapter must understand all proto3 and gRPC features:

  • https://developers.google.com/protocol-buffers/docs/reference/proto3-spec
  • https://developers.google.com/protocol-buffers/docs/proto3
  • http://www.grpc.io/docs/guides/concepts.html

• The environment variables API_HOST (IP address or hostname) and API_PORT (port number) must be provided to the API adapter, so the adapter can connect to the gRPC API.

• The environment variable API_PROTO_PATH can optionally be provided to the API adapter to load another proto3 file instead of the default /api/main.proto. Each API adapter must process and respect this variable if it is set.