ans-/gvm

Go Version Manager

gvm

by Josh Bussdieker (jbuss, jaja, jbussdieker) while working at Moovweb

GVM provides an interface to manage Go versions.

Features

• Install/Uninstall Go versions with gvm install [tag] where tag is "60.3", "go1", "weekly.2011-11-08", or "tip"
• List added/removed files in GOROOT with gvm diff
• Manage GOPATHs with gvm pkgset [create/use/delete] [name]. Use --local as name to manage repository under local path (/path/to/repo/.gvm_local).
• List latest release tags with gvm listall. Use --all to list weekly as well.
• Cache a clean copy of the latest Go source for multiple version installs.
• Link project directories into GOPATH

Background

When we started developing in Go mismatched dependencies and API changes plauged our build process and made it extremely difficult to merge with other peoples changes.

After nuking my entire GOROOT several times and rebuilding I decided to come up with a tool to oversee the process. It eventually evolved into what gvm is today.

Installing

To install:

bash < <(curl -s -S -L https://raw.githubusercontent.com/moovweb/gvm/master/binscripts/gvm-installer)

Or if you are using zsh just change bash with zsh

Installing Go

gvm install go1.4
gvm use go1.4 [--default]

Once this is done Go will be in the path and ready to use. $GOROOT and $GOPATH are set automatically.

Additional options can be specified when installing Go:

Usage: gvm install [version] [options]
    -s,  --source=SOURCE      Install Go from specified source.
    -n,  --name=NAME          Override the default name for this version.
    -pb, --with-protobuf      Install Go protocol buffers.
    -b,  --with-build-tools   Install package build tools.
    -B,  --binary             Only install from binary.
         --prefer-binary      Attempt a binary install, falling back to source.
    -h,  --help               Display this message.

A Note on Compiling Go 1.5+

Go 1.5+ removed the C compilers from the toolchain and replaced them with one written in Go. Obviously, this creates a bootstrapping problem if you don't already have a working Go install. In order to compile Go 1.5+, make sure Go 1.4 is installed first.

gvm install go1.4 -B
gvm use go1.4
export GOROOT_BOOTSTRAP=$GOROOT
gvm install go1.5

List Go Versions

To list all installed Go versions (The current version is prefixed with "=>"):

gvm list

To list all Go versions available for download:

gvm listall

Uninstalling

To completely remove gvm and all installed Go versions and packages:

gvm implode

If that doesn't work see the troubleshooting steps at the bottom of this page.

Mac OS X Requirements

• Install Mercurial from https://www.mercurial-scm.org/downloads
• Install Xcode Command Line Tools from the App Store.

xcode-select --install
brew update
brew install mercurial

Linux Requirements

Debian/Ubuntu

sudo apt-get install curl git mercurial make binutils bison gcc build-essential

Redhat/Centos

sudo yum install curl
sudo yum install git
sudo yum install make
sudo yum install bison
sudo yum install gcc
sudo yum install glibc-devel

• Install Mercurial from http://pkgs.repoforge.org/mercurial/

FreeBSD Requirements

sudo pkg_add -r bash
sudo pkg_add -r git
sudo pkg_add -r mercurial

Vendoring Native Code and Dependencies

GVM supports vendoring package set-specific native code and related dependencies, which is useful if you need to qualify a new configuration or version of one of these dependencies against a last-known-good version in an isolated manner. Such behavior is critical to maintaining good release engineering and production environment hygiene.

As a convenience matter, GVM will furnish the following environment variables to aid in this manner if you want to decouple your work from what the operating system provides:

1. ${GVM_OVERLAY_PREFIX} functions in a manner akin to a root directory hierarchy suitable for auto{conf,make,tools} where it could be passed in to ./configure --prefix=${GVM_OVERLAY_PREFIX} and not conflict with any existing operating system artifacts and hermetically be used by your workspace. This is suitable to use with C{PP,XX}FLAGS and LDFLAGS, but you will have to manage these yourself, since each tool that uses them is different.

2. ${PATH} includes ${GVM_OVERLAY_PREFIX}/bin so that any tools you manually install will reside there, available for you.

3. ${LD_LIBRARY_PATH} includes ${GVM_OVERLAY_PREFIX}/lib so that any runtime library searching can be fulfilled there on FreeBSD and Linux.

4. ${DYLD_LIBRARY_PATH} includes ${GVM_OVERLAY_PREFIX}/lib so that any runtime library searching can be fulfilled there on Mac OS X.

5. ${PKG_CONFIG_PATH} includes ${GVM_OVERLAY_PREFIX}/lib/pkgconfig so that pkg-config can automatically resolve any vendored dependencies.

Recipe for success:

gvm use go1.1
gvm pkgset use current-known-good
# Let's assume that this includes some C headers and native libraries, which
# Go's CGO facility wraps for us.  Let's assume that these native
# dependencies are at version V.
gvm pkgset create trial-next-version
# Let's assume that V+1 has come along and you want to safely trial it in
# your workspace.
gvm pkgset use trial-next-version
# Do your work here replicating current-known-good from above, but install
# V+1 into ${GVM_OVERLAY_PREFIX}.

See examples/native for a working example.

Troubleshooting

Sometimes especially during upgrades the state of gvm's files can get mixed up. This is mostly true for upgrade from older version than 0.0.8. Changes are slowing down and a LTR is imminent. But for now rm -rf ~/.gvm will always remove gvm. Stay tuned!