Please Go Modules rule generator

Generate Please go_module targets from your go.mod file.

Introduction

Please added official Go modules support in v16. However, it still requires you to manually write go_module targets. For large projects, that can be a heavy task.

This project helps with that task, by automatically generating a third_party/go/BUILD.plz file containing all modules required for your project.

Usage

Generate BUILD file from go.mod

Add the following snippet to your tools/BUILD file in the root of your repository:

remote_file(
    name = "godeps",
    url = f"https://github.com/sagikazarmark/please-go-modules/releases/latest/download/godeps_{CONFIG.HOSTOS}_{CONFIG.HOSTARCH}.tar.gz",
    extract = True,
    exported_files = ["godeps"],
    binary = True,
)

Add the following snippet to your .plzconfig:

[please]
version = 16.22.0

[alias "godeps"]
desc = Generate third-party dependency rules for a Go project
cmd = run //tools:godeps -- -dir third_party/go -clean -builtin

Run the following:

plz godeps

The above command will generate build targets in third_party/go for your third party dependencies.

Update BUILD files to use dependencies

You can combine the above with wollemi that can generate/update BUILD files in your project to use third-party dependencies.

Add the following content to your tools/BUILD file:

go_toolchain(
    name = "go_toolchain",
    version = "1.16.3",
)

WOLLEMI_VERSION = "v0.8.1"
remote_file(
    name = "wollemi",
    url = f"https://github.com/tcncloud/wollemi/releases/download/{WOLLEMI_VERSION}/wollemi-{WOLLEMI_VERSION}-{CONFIG.HOSTOS}-{CONFIG.HOSTARCH}.tar.gz",
    extract = True,
    exported_files = ["wollemi"],
    binary = True,
)

sh_cmd(
    name = "plz-tidy",
    cmd = [
        "export GOROOT=\\\\$($(out_exe :go_toolchain|go) env GOROOT)",
        "$(out_exe :godeps) -dir third_party/go -clean -builtin -wollemi",
        "$(out_exe :wollemi) gofmt ./...",
    ],
    deps = [
        ":godeps",
        ":wollemi",
        ":go_toolchain",
    ],
)

Note: You can remove any references to go_toolchain if you want to use Go installed on your system.

Finally, add an alias:

[alias "tidy"]
desc = Tidy generates build targets for dependencies and makes sure that BUILD files are up-to-date.
cmd = run //tools:plz-tidy

and run:

plz tidy

Note: the wollemi command might not work perfectly with Go submodules. You need to run wollemi for each module separately.