fdm

Forked Dependency Manager

An experimental dependency manager for Go, based on vendoring using GitHub forks.

Overview

Vendoring is the concept of taking a third-party dependency under your control. There are a number of different package managers out there for Go, some support vendoring while others don't. The typical approach seems to involve copying third-party code into your repository, probably with some sort of import rewriting.

fdm takes a different approach and assumes that you have forked the dependency. It uses symlinks to avoid having to do import rewriting.

The advantages of this approach are (hopefully):

• Follows GitHub friendly fork/PR workflow
• Keeps third-party code outside of your code repository resulting in a clean separation (gitignore _vendor)
• No import rewriting required thanks to symlinks
• Controlled by a Vendors file, making third-party dependencies explicit
• Pass arguments to git so you have full control over which is clone (branch, tag, commit etc)

The disadvantages of this approach are:

• Doesn't automatically download all dependecies (by design)

Installation

fdm is just a bash script, so simply download and stick it somewhere in PATH:

$ curl -O https://raw.githubusercontent.com/pki-io/fdm/master/fdm && chmod +x fdm && mv fdm /usr/local/bin

Usage

$ fdm --help
Usage: fdm [--help] [--debug] [--dev] [--exec COMMAND] [GO_ARGS]

If no arguments are given, fdm loads the Vendors file
Options:
    --help              This help
    --debug             Print debug info
    --dev               Enable dev mode. Use this to ignore the --git switch and use master
    --exec COMMAND      Execute COMMAND with modified GOPATH
    GO_ARGS             Any other arguments passed to go with modified GOPATH

Vendors file
------------

The vendors file is just a bash script, but fdm provides the 'vendor' function which works as follows:

vendor --repo REPO [--clone|--build] [--fork REPO] [--git COMMAND] [--pkg PACKAGE]

Options:
    -r, --repo REPO     Repository or upstream. E.g. github.com/them/their-project or github.com/you/your-project
    -c, --clone         Only perform clone actio
    -b, --build         Only perform build action
    -f, --fork REPO     Fork (vendored) repository E.g. github.com/you/their-project
    -g, --git COMMAND   Git command to run after clone. E.g. 'checkout 5c68cfdf2a545b5ff576c075b459d1fc0c606f82'
    -p, --pkg PACKAGE   Package to build if repo contains multiple packages
    --force             Force git command even in dev mode

Vendors file

In your repository, create a file called Vendors. E.g.

vendor -f "github.com/pki-io/docopt.go" -r "github.com/docopt/docopt-go" -g "checkout 854c423c810880e30b9fecdabb12d54f4a92f9bb"
vendor -f "github.com/pki-io/seelog" -r "github.com/cihub/seelog" -g "checkout 8762324945b8f31888f8bfa3bd7fca04c20e2639"
vendor -f "github.com/pki-io/toml" -r "github.com/BurntSushi/toml" -g "checkout 443a628bc233f634a75bcbdd71fe5350789f1afa"
vendor -f "github.com/pki-io/go-homedir" -r "github.com/mitchellh/go-homedir" -g "checkout 7d2d8c8a4e078ce3c58736ab521a40b37a504c52"
vendor -f "github.com/pki-io/ecies" -r "github.com/obscuren/ecies" -g "checkout 582e689ca8661237e08b02068435199ea8a55318"

vendor -f "github.com/pki-io/gojsonpointer" -r "github.com/xeipuuv/gojsonpointer" -g "checkout 636edb2500d21f2ed09ea96a00deb36bbd07cf70"
vendor -f "github.com/pki-io/gojsonreference" -r "github.com/xeipuuv/gojsonreference" -g "checkout 2df3c0c802434c5cb984dbc21425f5960bda4d16"
vendor -f "github.com/pki-io/gojsonschema" -r "github.com/xeipuuv/gojsonschema" -g "checkout 71b85f61a135e79143f3d3238d5175a4f29b6689"

vendor --clone -f "github.com/pki-io/crypto" -r "golang.org/x/crypto" -g "checkout 5c68cfdf2a545b5ff576c075b459d1fc0c606f82"
vendor --build -f "github.com/pki-io/crypto" -r "golang.org/x/crypto" -p "pbkdf2"

vendor --clone -r "github.com/pki-io/core" -g "checkout 03b63a18d74d2050828f7ab7d6943b114fdc1946"
if [[ "${FDM_ENV:-}" != "DEV" ]]; then
  for d in config crypto document entity fs index node x509; do
    vendor --build -r "github.com/pki-io/core" -p "$d"
  done
fi

This is just a bash script, so you can do loops etc as required.

It's just bash

Because the Vendors file is just bash, we can do clever things like group based on environment variable. In the above example, if fdm was called with FDM_ENV set to DEV, then it would skip the unforked_vendor_build code loop.

Examples

# Process the Vendors, installing all dependencies at the specified versions...
$ fdm

# Process the Vendors, but using master
$ fdm --dev

# Run the go tests
$ fdm test

# Run something else with the correct GOPATH
$ fdm --exec gover