Rails Docker

Develop Ruby on Rails with Docker!

• Ruby 2.5.0
• Rails 5.1.4

Prerequisite

Install Docker for your machine here.

Steps

1. Setup Docker
2. Connecting the Database
3. Up and Running

Setup Docker

• Building a new project
• Existing Project

Building a new project

Clone this repo:

$ git clone [email protected]:pdarden/railsbridgenyc_docker.git

Create your project directory:

• Remove git remote

$ git remote remove origin

• Change directory name

$ cd .. && mv railsbridgenyc_docker <<new_project_name>> && cd <<new_project_name>>

Create a bootstrap Gemfile which just loads Rails:

$ touch Gemfile

Open Gemfile in your editor:

source 'https://rubygems.org'
gem 'rails', '5.1.4'

Create an empty Gemfile.lock:

$ touch Gemfile.lock

Build new project:

$ docker-compose run web rails new . --force --database=postgresql

Build image again:

$ docker-compose build

Existing Project

Just add Dockerfile, docker-compose.yml, and run.sh to your project and run

$ docker-compose build

Connecting the Database

In config/database.yml replace the file with this content (feel free to rename the database, see <<my_app_name>>):

default: &default
  adapter: postgresql
  encoding: unicode
  username: postgres
  password:
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  host: <%= ENV.fetch("DB_HOST") %>
development:
  <<: *default
  database: <<my_app_name>>_development
test:
  <<: *default
  database: <<my_app_name>>_test
production:
  <<: *default
  database: <<my_app_name>>_production
  password: <%= ENV['APP_DATABASE_PASSWORD'] %>

Up and Running

• Setup the database for your project:

$ docker-compose run web rake db:create
$ docker-compose run web rake db:migrate

• Make run.sh excutable:

$ chmod +x run.sh

• Spinning up the rails server:

$ docker-compose up

Note: This will excute the commands in run.sh

• Visit http://localhost:3000 🚀

Useful commands

• docker-compose run web <<commands>>, runs commands in web service container E.g.,

$ docker-compose run web bin/rails c

• docker-compose run web bash, runs bash to interact with the directory inside the web service container
• docker-compose build, build image when Dockerfile changes or when you want to update or add gems.
• docker-compose up, starts up containers.
• docker-compose up -d, starts up containers in the background.
• docker-compose down, stops containers.
• docker-compose ps, view container processes, container name, container id.
• docker attach <<contianer_name>>, attach container to interact with binding.pry. Control + p Control + q , detach from container.

Guides

• https://docs.docker.com/compose
• https://docs.docker.com/compose/rails/#build-the-project