Heroku Buildpack: Go

This is a Heroku buildpack for Go.

Getting Started

Follow the guide at http://mmcgrana.github.com/2012/09/getting-started-with-go-on-heroku.html.

There's also a hello world sample app at https://github.com/kr/go-heroku-example.

Example

$ ls -A1
./.git
./.godir
./Procfile
./web.go

$ heroku create -b https://github.com/kr/heroku-buildpack-go.git
...

$ git push heroku master
...
-----> Fetching custom git buildpack... done
-----> Go app detected
-----> Installing Go 1.0.3... done
       Installing Virtualenv... done
       Installing Mercurial... done
       Installing Bazaar... done
-----> Running: go get -tags heroku ./...
-----> Discovering process types
       Procfile declares types -> web
-----> Compiled slug size: 1.0MB
-----> Launching... done, v5
       http://pure-sunrise-3607.herokuapp.com deployed to Heroku

The buildpack will detect your repository as Go if it contains a .go file.

The buildpack adds a heroku build constraint, to enable heroku-specific code. See the App Engine build constraints article for more.

Hacking on this Buildpack

To change this buildpack, fork it on GitHub. Push changes to your fork, then create a test app with --buildpack YOUR_GITHUB_GIT_URL and push to it. If you already have an existing app you may use heroku config:add BUILDPACK_URL=YOUR_GITHUB_GIT_URL instead of --buildpack.

.godir and Godeps

Early versions of this buildpack required users to create a .godir file in the root of the project, containing the application name in order to build the project. While using a .godir file is still supported, it has been deprecated in favor of using godep in your project to manage dependencies, and including the generated Godep directory in your git repository.

Using with cgo

This buildpack supports building with C dependencies via cgo. You can set config vars to specify CGO flags to, e.g., specify paths for vendored dependencies. E.g., to build gopgsqldriver, add the config var CGO_CFLAGS with the value -I/app/code/vendor/include/postgresql and include the relevant Postgres header files in vendor/include/postgresql/ in your app.

Setting the version at build time

If you set the GO_GIT_DESCRIBE_SYMBOL to the name of a string variable, it will be set at build time to the output of git describe --tags --always. This lets you access the commit id or tag in your app. For example, in your main.go:

package main

var version string

To set this variable at build time, set the config var:

$ heroku set GO_GIT_DESCRIBE_SYMBOL=main.version