# GzRelease

TODO: Write a gem description

## Installation

Add this line to your application's Gemfile:

```ruby
gem 'gz_release'
```

And then execute:

    $ bundle

Or install it yourself as:

    $ gem install gz_release

## Usage

### Rakefile

Add the following to your `Rakefile`:

``` ruby
require 'gz_release'

GzRelease::Tasks.install(
  image_name: 'gazelle/<PROJECT_NAME>'
)
```

This gives you a bunch of rake tasks:

```
rake release:build           # Builds the docker image from generated Dockerfile
rake release:dump            # Dumps docker cache into ~/.docker/image.tar
rake release:load            # Loads ~/.docker/image.tar into docker cache
rake release:pull            # Pulls latest version of the image from dockerhub
rake release:push:branch     # Pushes docker image tagged as current git branch
rake release:push:latest     # Pushes docker image tagged as latest
rake release:push:release    # Pushes docker image tagged as release
rake release:push:timestamp  # Pushes docker image and git tag tagged by the timestamp
rake release:push:version    # Pushes docker image tagged as version specified in Rakefile
rake release:tag:branch      # Creates a tag for the branch for the docker image
rake release:tag:latest      # Creates latest tag for the docker image
rake release:tag:release     # Creates release tag for the docker image
rake release:tag:timestamp   # Creates timestamp tag for the docker image and git repo
rake release:tag:version     # Creates a tag for version specified in Rakefile for docker image
```

### Environment variables

The following evironment variables are required for pushing to a docker repository: `DOCKER_USER`, `DOCKER_EMAIL`, `DOCKER_PASSWORD`. They are the same values you provide when doing `docker login`. It's best to use an organization account for these values on CircleCI.

Optionally, you can also set `DOCKER_REPOSITORY` (e.g. tutum.co), which will cause the image to be tagged for and pushed to that repository.

### Building on CircleCI

Create the environment variables for your project listed above on CircleCI. You can then have CircleCI build the docker image by creating a `circle.yml` including the following:

``` yaml
machine:
  services:
    - docker
checkout:
  pre:
    - git config --global user.email "circleci@gazelle.com"
    - git config --global user.name "Gazelle CircleCI Bot"
deployment:
  all:
    branch: /^(?!(master|dev)).*$/
    commands:
      - bundle exec rake release:build
      - bundle exec rake release:push:branch
  master:
    branch: master
    commands:
      - bundle exec rake release:build
      - bundle exec rake release:push:timestamp
      - bundle exec rake release:push:release
  dev:
    branch: dev
    commands:
      - bundle exec rake release:build
      - bundle exec rake release:push:latest
```

## Contributing

1. Fork it ( https://github.com/[my-github-username]/gz_release/fork )
2. Create your feature branch (`git checkout -b my-new-feature`)
3. Commit your changes (`git commit -am 'Add some feature'`)
4. Push to the branch (`git push origin my-new-feature`)
5. Create a new Pull Request