chatops_deployer setup for a simple Rails app

chatops_deployer.yml

# Which ports if which service need to be exposed as
# haikunated URLs
expose:
  app: [3000]

# These commands will be run in the specified order in each of the containers
# Note: Only DB changes are persisted, no other effects are persisted since
# only the DB data directory is inside a docker volume.
commands:
  - [app, "bin/setup"]

copy:
  - "./config/secrets.docker.yml.erb:config/secrets.yml"

database.docker.yml

# config/database.docker.yml

development:
  adapter: mysql2
  encoding: utf8
  collation: utf8_general_ci
  reconnect: true
  database: appname
  host: db
  port: 3306
  pool: 5
  username: root
  password: secret

docker-compose.yml

db:
  image: <private_docker_registry>:5000/mysql:5.6
  environment:
    - MYSQL_ROOT_PASSWORD=secret
    - MYSQL_DATABASE=appname

app:
  build: .
  command: bin/rails s -p 3000 -b '0.0.0.0'
  ports:
    - "3000"
  environment:
    - BUNDLE_PATH=/cache/tmp/bundler
    - DB_USER=root
    - DB_PASSWORD=secret
    - DB_HOST=db
    - DB_NAME=appname
  volumes_from:
    - cache
  links:
    - db

Dockerfile

# Use ruby:2.2 as the base image since this is a Rails app
FROM <private_docker_registry>/ruby:2.2
# Install necessary packages for running rails and connecting to DB
RUN apt-get update -qq && apt-get install -y build-essential nodejs mysql-client

RUN mkdir /web
WORKDIR /web
# Copy the project
ADD . /web/
COPY config/database.docker.yml /web/config/database.yml

secrets.docker.yml.erb

# config/secrets.docker.yml.erb

# If these are sensitive data, check out vault integration:
# https://github.com/code-mancers/chatops_deployer/blob/master/doc/using_vault.md
development:
  secret_key_base: db1fbe125905dd3cbab174f48e59daacb70fa674143d9d8118709074ca3b6f2647f0c475c93faae40684e022df51d771658041b23
  other_key: <VALUE>

setup

#!/usr/bin/env ruby

# File: bin/setup

require 'pathname'

# path to your application root.
APP_ROOT = Pathname.new File.expand_path('../../',  __FILE__)

def mysql_running
  system "mysql -h #{ENV['DB_HOST']} -u#{ENV['DB_USER']} -p#{ENV['DB_PASSWORD']} --batch --skip-column-names -e \"SHOW DATABASES LIKE '#{ENV['DB_NAME']}';\" | grep #{ENV['DB_NAME']}"
end

Dir.chdir APP_ROOT do
  # This script is a starting point to setup your application.
  # Add necessary setup steps to this file:

  puts "== Installing dependencies =="
  system "gem install bundler --conservative"
  system "bundle check || bundle install"

  puts "\n== Waiting until database is ready =="
  MAX_RETRY_COUNT = 30
  (1..MAX_RETRY_COUNT).each do |i|
    break if mysql_running
    if i == MAX_RETRY_COUNT
      fail "Reached max retry count of #{MAX_RETRY_COUNT}"
    end
    "Mysql server not up. Retrying"
    sleep 1
  end

  puts "\n== Preparing database =="
  system "bin/rake db:setup"
end