Go Dependency Manager (gdm)

gdm aims to do as little as possible. It will checkout dependencies to the local vendor directory and does not require that people use gdm to build your project. In this way, people can still simply go get your project and build.

We would recommend that you add vendor to your .gitignore file when using gdm.

This tool assumes you are working in a standard Go workspace, as described in http://golang.org/doc/code.html.

Install

go get github.com/sparrc/gdm

How to use gdm with a new project

Assuming your Go workspace is setup, so you can build your project with go install or go install ./..., it's one command to start using:

gdm save

This will create a new file in your repo directory called Godeps, which specifies project dependencies and their revisions. This file is identical to the file used by gpm.

Godeps is a simple text file of repo roots and revisions:

collectd.org/api 9fc824c70f713ea0f058a07b49a4c563ef2a3b98
collectd.org/network 9fc824c70f713ea0f058a07b49a4c563ef2a3b98
github.com/BurntSushi/toml 056c9bc7be7190eaa7715723883caffa5f8fa3e4

The file supports comments using the # character.

Vendor

The gdm vendor command is the opposite of gdm save. It will checkout the package versions specified in Godeps to the vendor directory.

Add a Dependency

To add a new package github.com/foo/bar, do this:

1. Run go get github.com/foo/bar
2. Run gdm save

Update a Dependency

To update a package to the latest version, do this:

1. Run rm -rf ./vendor
2. Run go get -u github.com/foo/bar
3. Run gdm save

Before committing the change, you'll probably want to inspect the changes to Godeps, for example with git diff, and make sure it looks reasonable.

Update all dependencies

To update all dependencies from your $GOPATH, do this:

1. Run rm -rf ./vendor
2. Run go get -u ./...
3. Run gdm save

Building a gdm project

Building a project managed by gdm looks like this:

1. Run go get github.com/foo/bar
2. Run cd $GOPATH/src/github.com/foo/bar
3. Run gdm vendor
4. Build: go install ./...

Homebrew

To help make a homebrew formula for your Go project, gdm supports a gdm brew command, which will print out your dependencies to stdout in the homebrew go_resource format, like this:

$ gdm brew
  go_resource "collectd.org/api" do
    url "https://github.com/collectd/go-collectd.git",
    :revision => "9fc824c70f713ea0f058a07b49a4c563ef2a3b98"
  end

  go_resource "collectd.org/network" do
    url "https://github.com/collectd/go-collectd.git",
    :revision => "9fc824c70f713ea0f058a07b49a4c563ef2a3b98"
  end

  go_resource "github.com/BurntSushi/toml" do
    url "https://github.com/BurntSushi/toml.git",
    :revision => "056c9bc7be7190eaa7715723883caffa5f8fa3e4"
  end

  ...

Restore

The gdm restore command works similar to the gdm vendor command, but instead of checking out the dependencies in the ./vendor directory, it will checkout the dependencies in your current GOPATH. This will modify repos in your GOPATH.

This can be useful for debugging or if you are using a Go version earlier than 1.9.

Acknowledgements

If you're familiar with Go dependency management, you can probably see the similarities with gpm and godep. This tool could not have existed without their influence!