database.yml

default: &default
  adapter: postgresql
  encoding: unicode
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>
  timeout: 5000
  host: db
  username: postgres
  password: 

development:
  <<: *default
  database: rocky_dev

# Warning: The database defined as "test" will be erased and
# re-generated from your development database when you run "rake".
# Do not set this db to the same as development or production.
test:
  <<: *default
  database: rocky_test

production:
  <<: *default
  database: rocky_production
  username: rocky
  password: <%= ENV['GOALIE_DATABASE_PASSWORD'] %>

rails_starter_2018_docker.md

How I create a rails app in 2018...

1. Create the repo and clone it
2. Create a dockerfile
3. Create a docker-compose file
4. Use docker-comose run web bash
5. Inside, run gem install rails && cd /app && rails new .

create a Dockerfile to build the "app"

RUN apt-get update -qq && apt-get install -y build-essential libpq-dev nodejs
RUN mkdir /myapp
WORKDIR /myapp
COPY Gemfile /myapp/Gemfile
COPY Gemfile.lock /myapp/Gemfile.lock
RUN bundle install
COPY . /myapp

Update Gemfile...

#replace sqlite3 with 
gem 'pg', '~> 0.18'

#Need authentication? Devise is good...
gem 'devise'
gem 'devise-bootstrap-views'

Update database.yml (See below)

run rails generate bootstrap:install to get the bootstrap generators. Might have to --force if you've already got some.

Handy commands

docker-compose build
docker-compose up
docker-compose down
docker compose run web bash