Vendors a set of go dependencies using 'gb-vendor', by reading a godep manifest (e.g. Godeps.json)

godep2gb.go

// aids in converting a godep project to a gb project:
//
// reads a Godeps.json manifest and uses the 'gb-vendor' plugin to vendor the
// same revision of each dependency into a gb-based project.
//
// Example:
//   To vendor all the dependencies of the godep-based project at /go/src/github.com/username/foo
//   into the new gb-based project at /path/to/gb/proj, run the following:
//
//    $ go run godep2gb.go -gbroot=/path/to/gb/proj/ -godeps=/go/src/github.com/username/foo/Godeps/Godeps.json
//
//   Note that this script will fail if any of the deps have already been vendored using gb-vendor.
package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io/ioutil"
	"os/exec"
)

var (
	gbRoot     string
	godepsPath string
)

type dep struct {
	ImportPath string `json:"ImportPath"`
	Rev        string `json:"Rev"`
}

type godepsManifest struct {
	Deps []dep `json:"Deps"`
}

func main() {
	flag.StringVar(&gbRoot, "gbroot", "", "the project root for the gb project")
	flag.StringVar(&godepsPath, "godeps", "", "path to the Godeps.json file to read")
	flag.Parse()

	var godeps godepsManifest

	file, err := ioutil.ReadFile(godepsPath)
	if err != nil {
		panic(err)
	}

	if err := json.Unmarshal(file, &godeps); err != nil {
		panic(err)
	}

	for _, dep := range godeps.Deps {
		fmt.Printf("vendoring pkg %s, rev %s...\n", dep.ImportPath, dep.Rev)

		cmd := exec.Command("gb", "vendor", "fetch", "--revision", dep.Rev, dep.ImportPath)
		cmd.Dir = gbRoot
		byts, err := cmd.CombinedOutput()
		if err != nil {
			fmt.Println(string(byts))
			panic(err)
		}
		fmt.Println(string(byts))
	}
}