Rat

Rat is a deploy tool for docker users. It implements a facade around 2 docker CLIs:

• docker
• docker-compose

It is not very flexible and it is untested lightly tested. I wrote this to avoid running a bunch of time consuming commands in a row.

I named it rat because it is a rather little and ugly ball of code, but it does the job for now.

Features

Rat deployer adds a thin layer of abstraction over docker-compose to make commands more DRY. Main features it adds are:

• Enviromental overrides by using multiple compose files
• Easier remote usage by linking environments to machines
• Slack notifier

Installation

$ gem install rat_deployer

Configuration

Rat searches for a file called rat_config.yml in the working dir. The options are:

• project_name: together with the environment, is part of the prefix passed to the --project option for docker-compose
• environments: holds environemntal config
  • [env]: parametric environment name
    • machine: configuration for remote usage. Links environment to a remote host. All paths can be relative to rat_config.yml file
      • host: IP for the remote machine
      • ca_cert: path to CA certificate
      • cert: path to SSL certificate used
      • key: path to SSL certificate key

Example config file:

project_name: myapp

environments:
  staging:
    machine:
      host:    tcp://107.170.36.78:2376
      ca_cert: certs/ca.pem
      cert:    certs/cert.pem
      key:     certs/key.pem

Env variable configuration

Rat most used options are set via environent variables to avoid having to type them all the time.

• RAT_ENV: current enviroment.
• RAT_REMOTE: whether or not to execute commands on remote host. Acceptable values are true and false. Defaults to true.

I recommend to export them if you are going to work on a environment for a long time:

$ export RAT_ENV=production RAT_REMOTE=false

Usage

• rat compose cmd: proxies command to docker-compose adding flags -f config/default.yml -f config/<env>.yml -p <prefix>. If RAT_REMOTE is true adds flags for running on remote host.
• rat deploy [services]: just an alias for rat compose pull [services] && rat compose up -d [services].
• rat docker cmd: proxies command to docker-compose adding flags for remote host ff RAT_REMOTE is true.

Example usage:

$ export RAT_ENV=staging
$ rat compose up -d
||=> Running command `docker-compose -f config/default.yml -f config/staging.yml -p cognituz_staging up -d`

Development

After checking out the repo, run bin/setup to install dependencies. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on GitHub at https://github.com/[USERNAME]/rat_deployer.

License

The gem is available as open source under the terms of the MIT License.