Protocol Buffers Data Type Go Code Generation

External

https://protobuf.dev/reference/go/go-generated

Internal

• Protocol Buffer Concepts

Overview

Protocol Buffer files are processed by the Protocol Buffer compiler protoc, which needs the Go plugin protoc-gen-go to generate Go code. The plugin is installed as described in the Installation section below. The protoc command line details are discussed in the Code Generation section.

Installation

The generic compiler must be installed with TODO.

To generate Go code, the Go plugin must be installed with:

go install google.golang.org/protobuf/cmd/protoc-gen-go@latest

This will install a protoc-gen-go binary in ${GOBIN}.

Code Generation

The compiler requires a mandatory source directory, specified with --proto_path, where it expects the find the .proto Protocol Buffer files. The Protocol Buffer files are individually specified on the command line, and each .proto file must be listed as relative to --proto_path.

For more details on a typical Go project layout, see:

Go Project Layout

  protoc \
    --proto_path=<protocol-buffer-source-directory> \
    --go_out=./pkg/person \
    --go_opt=Mperson.proto=. \
    <protocol-buffer-file-1>.proto <protocol-buffer-file-1>.proto ...

The compiler creates a single source file for each .proto command line-provided input file. The name of the output file is the name of the corresponding .proto file where the .proto extension is replaced with .pb.go. The newly created files will be placed under the directory specified by --go_out, but where exactly depends on the --go_opt compiler flags, as shown below. In the example above, a ./pkg/person/person.pb.go file will be created.

Arguments

--proto_path

The directory where to find the Protocol Buffer files. The individual Protocol Buffer files specified on the command line must be relative to this directory.

--go_out

The directory where the compiler writes the Go output. Where exactly in the directory depends on the value of the --go-opt value.