Docker + Docker Compose example

database.yml

default: &default
  adapter: postgresql
  encoding: unicode
  pool: 5 
  timeout: 5000
  username: postgres
  host: postgres
  port: 5432

development:
  <<: *default
  database: app_development

# 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: app_test

production:
  <<: *default
  database: app_production

docker-compose-dev.yml

version: "2"
volumes:
  web-sync:
    external: true
services:
  web:
    volumes:
      - web-sync:/b2beauty/beautydate:rw
      # - /Users/tiagopog/Dev/ruby/jsonapi-utils:/usr/local/bundle/gems/jsonapi-utils-0.4.3

docker-compose.yml

app:
  tty: true
  stdin_open: true
  build: .
  command: bash -c "rake db:create db:migrate db:migrate && rails s -p 3000 -b '0.0.0.0'"
  volumes:
    - .:/app
  environment:
    - FOO=bar
  ports:
    - "3000:3000"
  links:
    - postgres
db_data:
  image: busybox
  volumes:
    - /var/lib/postgresql/data
postgres:
  image: postgres:9.4
  volumes_from:
    - db_data
  ports:
    - "5432"

Dockerfile

FROM ruby:2.2.3
MAINTAINER tiagopog@gmail.com

# Install apt based dependencies required to run Rails as 
# well as RubyGems. As the Ruby image itself is based on a 
# Debian image, we use apt-get to install those.
RUN apt-get update && apt-get install -y \ 
  build-essential \ 
  nodejs

# Configure the main working directory. This is the base 
# directory used in any further RUN, COPY, and ENTRYPOINT 
# commands.
RUN mkdir -p /app 
WORKDIR /app

# Copy the Gemfile as well as the Gemfile.lock and install 
# the RubyGems. This is a separate step so the dependencies 
# will be cached unless changes to one of those two files 
# are made.
COPY Gemfile Gemfile.lock ./ 
RUN gem install bundler && bundle install --jobs 20 --retry 5

# Copy the main application.
COPY . ./

# Expose port 3000 to the Docker host, so we can access it 
# from the outside.
EXPOSE 3000

ENTRYPOINT ["bundle", "exec"]

# The main command to run when the container starts. Also 
# tell the Rails dev server to bind to all interfaces by 
# default.
CMD ["rails", "server", "-b", "0.0.0.0"]

Dockerfile (Node)

FROM node:4.4.7

RUN useradd --user-group --create-home --shell /bin/false app

ENV HOME=/home
ENV APP_PATH=$HOME/app
ENV LIB_PATH=$HOME/lib

RUN mkdir -p $APP_PATH &&\
    mkdir -p $LIB_PATH

WORKDIR $APP_PATH

COPY package.json $LIB_PATH

RUN chown -R app:app $HOME

USER app

RUN npm install --prefix $LIB_PATH --silent &&\
    npm install express --prefix $LIB_PATH --silent &&\
    npm install --prefix $LIB_PATH --save-dev nodemon --silent &&\
    npm cache clean &&\
    ln -s $LIB_PATH/node_modules/ node_modules

EXPOSE 3000

CMD ["node_modules/.bin/nodemon", "config/server.js"]

Dockerfile.gcloud

FROM gcr.io/google_appengine/ruby

RUN mkdir -p /app

WORKDIR /app

RUN cd /rbenv/plugins/ruby-build &&\
    git pull &&\
    rbenv install -s 2.3.0 &&\
    rbenv global 2.3.0 &&\
    gem install -q --no-rdoc --no-ri bundler --version 1.12.5

ENV RBENV_VERSION=2.3.0\
    HANAMI_ENV=production\
    APPSERVER=puma

COPY Gemfile* /app/
RUN bundle install --jobs 2 --retry 10 --binstubs --deployment

COPY . /app

EXPOSE 8080

ENTRYPOINT []

CMD ["bundle", "exec", "hanami", "server", "--host", "0.0.0.0", "--port", "8080", "--no-code-reloading"]

Dockerfile.gcloud.development

FROM gcr.io/google_appengine/ruby

RUN mkdir -p /app
WORKDIR /app

ENV RBENV_VERSION=2.3.0\
    HANAMI_ENV=development

RUN curl https://dl.google.com/dl/cloudsdk/channels/rapid/downloads/google-cloud-sdk-117.0.0-linux-x86_64.tar.gz\
    > /google-cloud-sdk-117.0.0-linux-x86_64.tar.gz
RUN tar xfvz /google-cloud-sdk-117.0.0-linux-x86_64.tar.gz -C / &&\
    rm -f /google-cloud-sdk-117.0.0-linux-x86_64.tar.gz
RUN /google-cloud-sdk/install.sh --quiet

ENV PATH /google-cloud-sdk/bin:$PATH

RUN gem install bundler
COPY Gemfile* /app/
RUN bundle install --jobs 4 --retry 10 --binstubs

COPY . /app

EXPOSE 8080

ENTRYPOINT []

CMD ["bundle", "exec", "shotgun", "--host", "0.0.0.0", "--port", "8080"]

node-docker-compose.yml

payments:
  build: .
  command: bash -c "node_modules/.bin/nodemon config/server.js"
  ports:
    - "3000:3000"
  expose:
    - "3000"
  volumes:
    - .:/home/app