protoc-gen-marshal-zap

protoc-gen-marshal-zap is a protoc plugin for implementing zapcore.ObjectMarshaler interface (uber-go/zap) on proto messages.

Requirements

• Go compiler and tools
• protoc compiler
• protoc-gen-go

See https://github.com/protocolbuffers/protobuf-go

Installation

go install github.com/kei2100/protoc-gen-marshal-zap/plugin/protoc-gen-marshal-zap@latest

Usage

Define your proto file

syntax = "proto3";

package simple;

// If you want to use "marshal_zap.mask" option, import "marshal-zap.proto"
import "marshal-zap.proto";

message SimpleMessage {

  string message = 1;

  string secret_message = 2 [(marshal_zap.mask) = true];

  // You can also use `debug_redact` option instead of `marshal_zap.mask` option
  // cf. https://github.com/protocolbuffers/protobuf/blob/v22.0/src/google/protobuf/descriptor.proto#L632
  string secret_message2 = 3 [debug_redact = true];
}

Generate the code by protoc (Alternatively, you can use buf)

PROTOC_GEN_MARSHAL_ZAP_VERSION=v0.1.x  # replace latest version
protoc -I. -I$(go env GOMODCACHE)/github.com/kei2100/protoc-gen-marshal-zap@${PROTOC_GEN_MARSHAL_ZAP_VERSION} --go_out=. --marshal-zap_out=. simple.proto

# If you don't use `marshal_zap.option`, it's even simpler
# protoc -I. --go_out=. --marshal-zap_out=. simple.proto

Output results should be:

simple.pb.go              # auto-generated by protoc-gen-go
simple.pb.marshal-zap.go  # auto-generated by protoc-gen-marshal-zap
simple.proto              # original proto file

simple.pb.marshal-zap.go is generated as follows

// Code generated by protoc-gen-marshal-zap. DO NOT EDIT.
// source: simple.proto

package simple

import (
        "go.uber.org/zap/zapcore"
)

func (x *SimpleMessage) MarshalLogObject(enc zapcore.ObjectEncoder) error {
        if x == nil {
                return nil
        }

        enc.AddString("message", x.Message)

        enc.AddString("secret_message", "[MASKED]")

        enc.AddString("secret_message2", "[MASKED]")

        return nil
}

Using Buf

marshal-zap Buf repository is here.

https://buf.build/kei2100/protoc-gen-marshal-zap

So, you can buf generate by setting up the following in your project.

# buf.yaml
version: v1
deps:
  - buf.build/kei2100/protoc-gen-marshal-zap
breaking:
  use:
    - FILE
lint:
  use:
    - DEFAULT

# buf.gen.yaml
version: v1
plugins:
  - plugin: buf.build/protocolbuffers/go:v1.28.1
    out: gen/go
    opt: paths=source_relative
  - plugin: marshal-zap
    out: gen/go
    opt: paths=source_relative

Development

Compile marshal-zap.proto

$ make proto

Run tests

$ make test