protocore

Everything needed to generate protobuf files for common languages used across OpenLaw, with zero dependencies.

Includes the default protoc protocol buffer code generation tool, along with dev extensions.
Adds plugins for support for the following language generation:
- Scala
- Go
- TypeScript
- Documentation

All plugins are compiled into native binaries and compressed via UPX. As a result, this image is relatively quite small (50mb uncompressed), and does not require any runtime dependencies such as the JVM or NodeJS.

Usage

Typically you won't be invoking this directly unless you need it -- it is primarily intended for reproducible builds across CI and Makefiles.

Generally, you can just treat openlaw/protocore as an environment that has the protoc and all the plugins tools setup and in the path. Protocore uses /src as it's default WORKDIR, so if you volume mount the directory you want to work on to there, you can use it to generate files in your local filesystem.

Simple command line usage

Create Scala bindings for helloworld.proto in your current working directory.

$ docker run --rm -it -v "$(pwd)":/src openlaw/protocore \
    protoc --scala_out=. helloworld.proto

In a script or makefile

Here's a more sophisticated example that simultaneously generates gRPC compatible bindings for Go, Javascript with TypeScript definitions, and Scala -- as well as using docgen to produce a README.md documenting the spec.

docker run --rm -it \
    -v "$(pwd)":/src \
    openlaw/protocore protoc \
        --go_out=plugins=grpc:. \
        --js_out=import_style=commonjs,binary:. \
        --ts_out=. \
        --scala_out=. \
        --doc_out=. --doc_opt=markdown,README.md \
        helloworld.proto

You can see a more full version of this (with output subdirectories and a Makefile) in the example/ directory.

Aliasing

If you work directly with protocore from the command line often (doubtful, but it's possible!), you may wish to make an alias such as:

alias protocore='docker run --rm -it -v "$(pwd)":/src openlaw/protocore'

This enables you to simply prepend protocore to any protoc command you may with to run while working with your local filesystem, and have it work in the controlled container environment without requiring you to configure stuffs locally:

$ protocore protoc --scala_out=. helloworld.proto

Other handy tools for working with protobuf

VS Code editor support (syntax highlighting, linting): https://marketplace.visualstudio.com/items?itemName=zxh404.vscode-proto3