Docker Development Environment

A development environment for Rails applications using docker.

Tested on Linux and Mac OS X.

Requirements

Docker
VirtualBox (only on OSX)
boot2docker (only on OSX)

Install on OSX (using Homebrew)

Musophobia? Read on:

brew tap phinze/homebrew-cask
brew install brew-cask
brew cask install virtualbox
brew cask install boot2docker
brew install docker

Install on Linux (Tested on Ubuntu and Fedora

# Install docker
curl -sL https://get.docker.io/ | sudo sh
sudo adduser $USER docker

Install living-in-a-box

git clone https://github.com/gewo/living-in-a-box.git $HOME/.living-in-a-box
export PATH="~/.living-in-a-box/bin:$PATH" # you want to make this permanent

Docker images

Get started

First you want to start the background services, that is:

redis
mongodb
mysql

On OSX a the boot2docker VM will be started for the docker daemon, which is not available on OSX.

# Start it up. On the first run it will pull all the necessary images
# from the docker registry.
dev start

Start developing

From your project folder just run:

dev shell

This will open a bash shell inside the docker container with the background services linked to it. The /mnt-folder inside the container is synced to your current path.

An example:

$ cd /path/to/project
$ dev shell
docker$ cd /mnt # equals /path/to/project on the host
docker$ bundle install
docker$ bundle exec rake db:create db:schema:load db:migrate db:seed
docker$ bundle exec rails server
docker$ exit
$

Data in the background-services will be persisted in Data Volumes.

Environment Variables

PORT

Normally the containers port is mapped to a random port on your host machine. You can specify the PORT environment variable to use a fixed one:

$ dev shell             # port 3000 forwarded to 0.0.0.0:49157
$ PORT=3456 dev shell   # port 3000 forwarded to 0.0.0.0:3456

SYNC_DOTFILES

When setting SYNC_DOTFILES=1 a few of your favorite dotfiles are bind-mounted inside the container and your shell is set to zsh if that's also your current $SHELL.

When you want to specify custom files that should be synced into your containers home directory you can set the DOTFILES environment variable.

$ SYNC_DOTFILES=1 dev shell                    # sync default dotfiles
$ SYNC_DOTFILES=1 DOTFILES=".ctags" dev shell  # sync your `~/.ctags`

SHELL

Set the shell to use in your container.

$ SHELL=fish dev shell
docker <><

EXTRA_ARGS

Sometimes you may want to pass additional arguments to the docker run command.

Lets say you want to forward the Redis port to your local system:

$ EXTRA_ARGS="--publish 127.0.0.1:9736:6379" dev shell
docker$

# another shell on your host
$ redis-cli -p 9736 INFO | grep redis_version
redis_version:2.6.15
$

RUBY_VER

Per default dev shell uses the gewo/ruby image. Some guessing is done to automatically find out the correct version of ruby from your Gemfile. Sometimes you want to specify the version manually:

$ RUBY_VER=1.9.3 dev shell
docker$ ruby -v
ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-linux]
docker$

IMAGE

The docker image. IMAGE by default is the latest ruby image.

$ IMAGE=gewo/ruby:1.9.3 dev shell
docker$ ruby -v
ruby 1.9.3p392 (2013-02-22 revision 39386) [x86_64-linux]
docker$

{MONGODB,REDIS,MYSQL}_VER

Set version of background services on dev start

$ # Run the mongodb server with image gewo/mongodb:2.4.10. Other images
$ # use :latest per default.
$ MONGODB_VER=2.4.10 dev start

Commands

shell

dev shell [IMAGE]

IMAGE by default is the latest ruby image.

Example

$ dev shell gewo/node
docker$ nodejs -v
v0.10.29
docker$

TODO

A lot.

gapfish / living-in-a-box