protodoc

protodoc generates Protocol Buffer documentation.

go get -v -u go.etcd.io/protodoc

protodoc --directory=./parse/testdata \
    --parse="service,message" \
    --languages="Go,C++,Java,Python" \
    --title=testdata \
    --output=sample.md

# to combine multiple directories into one
protodoc --directories=./parse/testdata=service,dirA=service_message \
    --languages="Go,C++,Java,Python" \
    --title=testdata \
    --output=sample.md

Note that parser only understands the minimum syntax of Protocol Buffer (just enough to generate documentation).

For full featured parser, please check out https://github.com/golang/protobuf.