[golang] project layout and package name linting

[Big-Iron-Cheems]

First time using this tool to generate my sources from .proto files.
I am having some difficulties in understanding the layout that I'm supposed to use.
Below is my current state of the project, with an example file from it.

# buf.yaml
version: v2

lint:
  use:
    - STANDARD
breaking:
  use:
    - FILE

modules:
  - path: cmd/test_lab/proto

# buf.gen.yaml
version: v2

plugins:
  - local: protoc-gen-go
    out: cmd/test_lab/pb
    opt: paths=source_relative

inputs:
  - directory: cmd/test_lab/proto

// keyboard_message.proto
syntax = "proto3";

package cmd.test_lab.proto;  //< This is the part that the linter complains about

option go_package = "cmd/test_lab/pb";

message Keyboard {
  enum Layout {
    UNKNOWN = 0;
    QWERTY = 1;
    QWERTZ = 2;
    AZERTY = 3;
  }

  Layout layout = 1;
  bool backlit = 2;
}

# Project structure
.
├── buf.gen.yaml
├── buf.yaml
├── cmd
│   └── test_lab
│       ├── main.go
│       ├── pb
│       │   ├── keyboard_message.pb.go
│       │   ├── laptop_message.pb.go
│       │   ├── memory_message.pb.go
│       │   ├── processor_message.pb.go
│       │   ├── screen_message.pb.go
│       │   └── storage_message.pb.go
│       └── proto
│           ├── keyboard_message.proto
│           ├── laptop_message.proto
│           ├── memory_message.proto
│           ├── processor_message.proto
│           ├── screen_message.proto
│           └── storage_message.proto
├── go.mod
└── go.sum

While this builds fine when calling buf generate, I still get the following warning when I do buf lint cmd/test_lab/proto/keyboard_message.proto:

Files with package "cmd.test_lab.proto" must be within a directory "cmd/test_lab/proto" relative to root but were in directory ".".

It is clear that this has to do with the package name and the position of the .proto files.
Let me know if I am misunderstanding how this is supposed to work, I am a complete newbie in this field.

[emcfarlane]

Hi @Big-Iron-Cheems, this is an issue with the path to the module as specified in the buf.yaml as - path: cmd/test_lab/proto. This path makes each file under test_lab at the '.' (root) directory. So another module importing this module would import the proto file as:

import "keyboard_message.proto"

This is probably not what you'd want. You can remove the modules: section in the yaml to get the default path . which would make the file imported in other modules as:

import "cmd/test_lab/proto/keyboard_message.proto"

Have a look at the style guide for best practises and let me know if you have any issues!

[Big-Iron-Cheems]

Removing the modules section and adjusting the imports would result in this structure, where cmd/test_lab/pb/cmd/test_lab/proto/keyboard_message.pb.go doesn't look quite right.

.
├── buf.gen.yaml
├── buf.yaml
├── cmd
│   └── test_lab
│       ├── main.go
│       ├── pb
│       │   └── cmd
│       │       └── test_lab
│       │           └── proto
│       │               ├── keyboard_message.pb.go
│       │               ├── laptop_message.pb.go
│       │               ├── memory_message.pb.go
│       │               ├── processor_message.pb.go
│       │               ├── screen_message.pb.go
│       │               └── storage_message.pb.go
│       └── proto
│           ├── keyboard_message.proto
│           ├── laptop_message.proto
│           ├── memory_message.proto
│           ├── processor_message.proto
│           ├── screen_message.proto
│           └── storage_message.proto
├── go.mod
└── go.sum

It would seem that most docs expect proto to be at the project root, and for it to mirror the folder structure in cmd.

[Big-Iron-Cheems]

Update (with image for clarity): this seems to work like I intended now:

• have everything in one proto folder
• have the gen code go in a pb folder
• no lint related to package name

I'm sure that from this example I'll be able to expand easily for any given structure.
Thanks for your input 👍

[emcfarlane]

For generating the go code have a look at the source_relative option. You might find this tutorial helpful.

  - local: protoc-gen-go
    out: gen
    opt:
      - paths=source_relative

Edit: great I missed that you had applied it already. Glad you got it working!