This is my basic Rails app template for beginning development with Docker.

• Rails version: 4.2.1
• Ruby version: 2.2.0

Docker images used:

• passenger-docker
• postgres
• redis

It runs the application as the app user. The database owner is the myapp_user. To customize this template, grep for myapp and replace all occurrences.

First, decide which environment you wish to use. Copy the selected environment file into .env. For example:

cp .env.development .env

Be sure to define any of the environment variables without values.

Any added environment variables must also be added to rails-env.conf so that they're exposed to Nginx child processes (more info).

Docker Compose is used for linking containers.

First, build the included Dockerfiles:

docker-compose build

Then, start the web app:

docker-compose up

Finally, create the database:

docker exec myapp_web_1 bin/rake db:create

Further commands can be executed in this way.

The app is exposed on port 80 by default. If using Boot2Docker, enter its IP address in your browser.

This template uses Sidekiq for background processing. A Redis container is linked to enable Sidekiq to work. Once the app is started, Sidekiq provides a monitoring tool at /sidekiq.

To start Sidekiq and process jobs: bin/sidekiq

Sidetiq is used to create scheduled jobs. Scheduled jobs should go under app/workers/scheduled/ and will be automatically loaded even in the development environment.

For TDD, this template includes the following:

• rspec-rails
• factory_girl_rails
• shoulda
• faker

Be sure to create:

• SECRET_BASE_KEY via bin/rake secret
• myapp_prod_user with a password for MYAPP_PROD_USER_DATABASE_PASSWORD

docker-compose up will create a Docker 'web' container named <base-directory-name>_web_1.

The following Bash function:

# ddo -> 'docker-do'
function ddo { docker exec -it `basename $PWD | sed s/[-_]//g`_web_1 $* }

allows:

# Create the database
ddo bin/rake db:create

# Run specs
ddo bin/rspec

# Start a Bash login shell
ddo bash -l