install a rails 4 stack (ruby + nginx + unicorn + mysql) just using bash and system packages. not the best way, but just for fun

bash-rails-stack.sh

#!/usr/bin/env bash
set -e

#### Adding everything INLINE just for sending you an unique gist
## Test: Run an amazon ubuntu 14.04 image, copy and run the script. 
## Run `wget localhost` or connect to aws server IP for getting your greeting :)


#source config.variables
RUBY_PACKAGE="ruby2.0"
MYSQL_SERVER_PACKAGE="percona-server-server-5.5"
MYSQL_CLIENT_PACKAGE="percona-server-client-5.5"
RAILS_PACKAGE="ruby-rails-4.0"
RAILS_DEPENDENCIES="libmysqlclient-dev nodejs"
UNICORN_PACKAGE="unicorn"

APP_NAME="koding"
WEB_APP_PATH="/var/www/${APP_NAME}"

UNICORN_CONFIG_RB="${WEB_APP_PATH}/config/unicorn.conf.rb"
UNICORN_CONFIG_DEFAULT="/etc/default/unicorn"

NGINX_SITE_FILE="/etc/nginx/sites-available/default"

DB_USER="koding"
DB_PASSWD="koding"

export DEBIAN_FRONTEND=noninteractive


#source helper.functions 
update_package_list () {
  apt-key update
  apt-get update
}

install_percona_repository () {
  wget https://repo.percona.com/apt/percona-release_0.1-3.$(lsb_release -sc)_all.deb
  dpkg -i percona-release_0.1-3.$(lsb_release -sc)_all.deb
}

install_mysql_server () {
  server_package=$1
  client_package=$2
  
  debconf-set-selections <<< "${server_package} $(cut -d "-" -f1-3 <<< $server_package)/root_password password "
  debconf-set-selections <<< "${server_package} $(cut -d "-" -f1-3 <<< $server_package)/root_password_again password "
  apt-get install -y $client_package $server_package
}

install_percona () {
  packages="${@}"
  
  install_percona_repository
  update_package_list
  install_mysql_server $packages
}

create_rails_app () {
  path=$1
  
  rails new $path --database mysql
}

create_db_users () {
  db_user=$1
  db_passwd=$2
  
  mysql <<< "CREATE USER '${db_user}'@'localhost' IDENTIFIED BY '${db_passwd}';" 
  mysql <<< "GRANT ALL PRIVILEGES ON * . * TO '${db_user}'@'localhost';" 
  mysql <<< "FLUSH PRIVILEGES;"
}

configure_rails_app () {
  path=$1
  db_user=$2
  db_passwd=$3
  shift 3
  deps="${@}"
  
  apt-get install -y $deps
  
  cd $path

  echo "gem 'bundler'" >> Gemfile
  sed -i "s~\(gem 'mysql2'\).*~\1, '\~> 0.3.18'~" Gemfile

  bundle install

  cat > $path/config/databases.yml << EOF
  development:
    adapter: mysql2
    encoding: utf8
    reconnect: false
    database: $(basename $path)_development
    pool: 5
    username: ${db_user}
    password: ${db_password}
    host: localhost
EOF

  export RAILS_ENV=development

  bundle exec rake db:create
  bundle exec rake db:migrate
  bundle exec rake assets:precompile
  }

add_hello_world () {
  path=$1
  
  cd $path
  bundle exec rails generate controller welcome index

  cat > app/controllers/welcome_controller.rb << EOF
  class WelcomeController < ApplicationController
    def index
      @greeting = "Hi Koding!"
    end
  end
EOF

  cat > app/views/welcome/index.html.erb << EOF
  <h1><%= @greeting %></h1>
EOF

  cat > config/routes.rb << EOF
  Koding::Application.routes.draw do
    get  'welcome/index'
    root 'welcome#index'
  end
EOF

}

configure_unicorn () {
  app_root=$1
  unicorn_config=$2
  unicorn_default_config=$3
  
  
  sed -i 's/\(CONFIGURED=\)no/\1yes/' $unicorn_default_config
  sed -i "s~\(APP_ROOT=\).*~\1${app_root}~" $unicorn_default_config
  sed -i "s~\(CONFIG_RB=\).*~\1${unicorn_config}~" $unicorn_default_config
  sed -i "s~\(PID=\).*~\1${app_root}/shared/pids/unicorn.pid~" $unicorn_default_config 

  cat > $unicorn_config << EOF
    # set path to application
    app_dir = File.expand_path("../..", __FILE__)
    shared_dir = "#{app_dir}/shared"
    working_directory app_dir

    # Set unicorn options
    worker_processes 2
    preload_app true
    timeout 30

    # Set up socket location
    listen "#{shared_dir}/sockets/unicorn.sock", :backlog => 64

    # Logging
    stderr_path "#{shared_dir}/log/unicorn.stderr.log"
    stdout_path "#{shared_dir}/log/unicorn.stdout.log"

    # Set master PID location
    pid "#{shared_dir}/pids/unicorn.pid"
    
EOF

  mkdir -p $app_root/shared/pids $app_root/shared/sockets $app_root/shared/log
}

configure_nginx () {
  app_root=$1
  nginx_site_file=$2

  cat > $nginx_site_file << EOF
  upstream app {
      # Path to Unicorn SOCK file, as defined previously
      server unix:${app_root}/shared/sockets/unicorn.sock fail_timeout=0;
  }

  server {
      listen 80;
      server_name localhost;

      root ${app_root}/public;

      try_files \$uri/index.html \$uri @app;

      location @app {
          proxy_pass http://app;
          proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for;
          proxy_set_header Host \$http_host;
          proxy_redirect off;
      }

      error_page 500 502 503 504 /500.html;
      client_max_body_size 4G;
      keepalive_timeout 10;
  }
EOF

}


#### main Script  

install_percona $MYSQL_SERVER_PACKAGE $MYSQL_CLIENT_PACKAGE

apt-get install -y $RUBY_PACKAGE $RAILS_PACKAGE
create_rails_app $WEB_APP_PATH
configure_rails_app $WEB_APP_PATH $DB_USER $DB_PASSWD $RAILS_DEPENDENCIES
create_db_users $DB_USER $DB_PASSWD
add_hello_world $WEB_APP_PATH

apt-get install -y $UNICORN_PACKAGE
configure_unicorn $WEB_APP_PATH $UNICORN_CONFIG_RB $UNICORN_CONFIG_DEFAULT
service unicorn start

apt-get install -y nginx
configure_nginx $WEB_APP_PATH $NGINX_SITE_FILE
service nginx restart