Ruby on Rails

From ArchWiki
Jump to navigation Jump to search




Ruby on Rails requires Ruby to be installed, so read that article first for installation instructions. The nodejs package is also required if using uglifier (Ruby wrapper for UglifyJS JavaScript compressor, optional) The Rails framework is linked to a version of Ruby (or the system Ruby installation). Ruby version(s) installed can be from system or from rbenv or from rvm (Ruby Version Manager).


Note: You can also install Rails system-wide using Gems. To do this, run the following commands as root and append them with --no-user-install. Please read Ruby#Installing gems per-user or system-wide for possible dangers of using RubyGem in this way.

The following command will install Rails for the current user:

$ gem install rails

Building the documentation takes a while. If you want to skip it, append --no-document to the install command.

$ gem install rails --no-document


$ gem update


Install the ruby-railsAUR package. Alternatively, see Ruby#Managing RubyGems using pacman.

Quarry binary repository

Install ruby-rails from the unofficial quarry repository.



$ rails new testapp_name
Note: If you get an error like Errno::ENOENT: No such file or directory (...) An error occurred while installing x, and Bundler cannot continue., you might have to configure Bundler so that it installs gems per-user and not system-wide. Alternatively, run # rails new testapp_name once as root. If it has completed successfully, delete testapp_name/ and run $ rails new testapp_name again as a regular user.

This creates a new folder inside your current working directory.

$ cd testapp_name


$ rails server



A test-page should be shown greeting you "Welcome aboard".

Application servers

The built-in Ruby On Rails HTTP server (WeBrick for version 4.X of Rails, and Puma for version 5.X) is convenient for basic development, but it is not recommended for production use. Instead, you should use an application server such as #Thin, #Unicorn or Phusion Passenger.


Thin is a fast and very simple Ruby web server.

First install thin gem:

$ gem install thin

Then start it using:

$ thin start


Unicorn is an application server that cannot talk directly to clients. Instead, a web server must sit between clients and Unicorn, proxying requests as needed. Unicorn is loosely based on Mongrel. It is used by Github, and it uses an architecture that tries hard to find the best child for handling a request. Explanation of differences between Unicorn and Mongrel.

Install the Unicorn gem:

# gem install unicorn


working_directory "/srv/http/redmine"
pid "/tmp/"

preload_app true
timeout 60
worker_processes 4
listen 4000

GC.respond_to?(:copy_on_write_friendly=) and GC.copy_on_write_friendly = true

after_fork do |server, worker|
	addr = "{4000 +}"
	# infinite tries to start the worker

	#Drop privileges if running as root

Start it using:


Systemd service


Description=Unicorn application server



You can now easily start and stop unicorn using systemctl

Nginx Configuration

After setting up Nginx, configure unicorn as an upstream server using something like this (Warning: this is a stripped example. It probably does not work without additional configuration):

http {
	upstream unicorn {
		server fail_timeout=0;
		server fail_timeout=0;
		server fail_timeout=0;
		server fail_timeout=0;

	server {
		listen		80 default;

		location / {
			root			/srv/http/redmine/public;
			proxy_set_header	X-Forwarded-For $proxy_add_x_forwarded_for;
			proxy_set_header Host   $http_host;
			proxy_redirect		off;
			proxy_pass		http://unicorn;

Apache/Nginx (using Phusion Passenger)


Two differents choices (one or the other, not both in same time):

1/ Archlinux now has packages officialy support server modules to be compiled with passenger:

 # pacman -Syu passenger

2/ Start by installing the 'passenger' gem from any version of ruby (user setting):

# gem install passenger

If you are aiming to use Apache, run:

# pacman -Syu mod_passenger (if passenger is not installed from gem)
# passenger-install-apache2-module

In case a rails application is deployed with a sub-URI, like, some additional configuration is required, see the modrails documentation

For Nginx:

# pacman -Syu nginx-mod-passenger (if passenger is not installed from gem)
# passenger-install-nginx-module


To serve an application with Nginx, configure it as follows:

server {
    passenger_enabled on;
    rails_env development; # Rails environment.

Puma (with Nginx as reverse proxy server)

Puma (Github Page) is a simple, fast, threaded, and highly concurrent HTTP 1.1 server for Ruby/Rack applications, and is considered the replacement for Webrick and Mongrel. It was designed to be the go-to server for Rubinius, but also works well with JRuby and MRI. While reverse proxy server would acts as a load balancer that routes all external requests to a pool of web apps.

For a webserver it is better to use a server user and group, check Users and groups#Example adding a user, below use rails as user name and server as group name, also my_app as rails app name.

Start by copying your app to /var/www/my_app. And set new ownership with

# cd /var/www/
# chown -R rails:server my_app

and permission for user with

# chmod -R 775 my_app

Then add puma gem in the Gemfile and install with

$ cd my_app 
$ bundle install

Also install nginx by pacman.

Under your app folder, create sockets, pid and log folder with

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

Backup nginx.conf with

# cp /etc/nginx/nginx.conf /etc/nginx/nginx.conf.backup

Then create a new nginx.conf file with your favorite editor, copy codes below and modify as you like:

#user html;
worker_processes  1; # this may connect with the worker numbers puma can use.

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/;

events {
    worker_connections  1024;

http {
	upstream app {
	    # Path to Puma SOCK file, as defined previously
 	    server unix:/var/www/my_app/shared/sockets/puma.sock;

	server {
	    listen 80;
	    server_name localhost; # or your server name

	    root /var/www/my_app/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;

Start the nginx service.

There are several ways to start puma server, two ways are recommended below:

In common create file config/puma.rb, copy codes below and modify as you like:

# Change to match your CPU core count
# You can check available worker numbers with $ grep -c processor /proc/cpuinfo
# also see the comment in the nginx.conf
workers 2

# Min and Max threads per worker
#threads 1, 6

shared_dir = "#{app_dir}/shared"

# Default to production
#rails_env = ENV['RAILS_ENV'] || "production"
#environment rails_env

# Set up socket location

# Logging

# Set master PID and state locations
pidfile "#{shared_dir}/pids/"
#state_path "#{shared_dir}/pids/puma.state"

#on_worker_boot do
#  require "active_record"
#  ActiveRecord::Base.connection.disconnect! rescue ActiveRecord::ConnectionNotEstablished
#  ActiveRecord::Base.establish_connection(YAML.load_file("#{app_dir}/config/database.yml")[rails_env])

Option A: With config file

Start server with

$ bundle exec puma -C config/puma.rb

You can also run it in background with parameter -d and check with

$ pgrep puma

when you want to kill it.

If you want to keep it after you log out, you can use

$ nohup bundle exec puma -C config/puma.rb &

But if the system reboot, the process will still get lost.

Option 2: by systemd

Create a new systemd unit puma.service under ~/.config/systemd/user/ and copy codes below

Description=Puma application server

ExecStart=/home/rails/.gem/ruby/2.2.0/bin/bundle exec \
	 /home/rails/.gem/ruby/2.2.0/bin/puma \
	 -C /var/www/my_app/config/puma.rb


Hint: For ExecStart, if you've installed gem globally, you can change routes to /usr/local/bin/ in ExecStart.

Then start puma with

$ systemctl --user start puma

To enable puma system-widely: You need to store puma.service in /etc/systemd/system/ and modify it as below:

Description=Puma application server

	 -C /var/www/my_app/config/puma.rb


For further reading take a look at #References. Also, for easily deploying app in production mode, you can try capistrano


Most web applications will need to interact with some sort of database. ActiveRecord (the ORM used by Rails to provide database abstraction) supports several database vendors, the most popular of which are MySQL, SQLite, and PostgreSQL. And then you will have next to configure the file "config/database.yml" for Rails application web site able to connect on your database.


SQLite is the default lightweight database for Ruby on Rails. To enable SQLite, simply install sqlite.


Install postgresql.

Install for Rails:

# gem install pg

Or add the gem inside your Gemfile of your project, then use bundle.

create a new Rails web site:

# rails new my_web_site -d postgresql




# gem install mysql


$ rails new testapp_name -d mysql

Database Access Configuration

What ever Database (MySQL or Postgresql or SQlite (the default one) you use, you then need to edit config/database.yml. Rails uses different databases for development, testing, production and other environments. Here is an example development configuration for MySQL running on localhost:

   adapter: mysql (or postgresql or sqlite)
   username: my_user_name_access
   password: my_secret_password

For safety reasons, it is a good practice to not directly put password (who will be no more secret) as clear text in a text file. Instead you can replace "my_secret_password' by "'<%= ENV["MYSQL_PASSWD"] %>'" where MYSQL_PASSWD can be an environment variable exported from the user environment the server use (~/.profile or ~/.bashrc or ~/.zshrc depend of your choice and utility). Surrounding <%= ENV.... %> by "'" searve in case of your password has some special chars like # or !, etc...

Create the databases from Rails

Note that you do not have to actually create the database using MySQL or Postgresql or Sqlite, as this can be done via Rails directly with:

For rails-4.X version:

# rake db:create

For rails-5.X version:

# rails db:create (for version of Rails-5.X)


The Perfect Rails Setup


Reason: Bloggish title, content mostly just reiterates the things mentioned above. (Discuss in Talk:Ruby on Rails#)

Phusion Passenger running multiple Ruby versions.

  • Arch Linux: A simple, lightweight distribution. ;)
  • SQLite: The default lightweight database for Ruby on Rails.

Step 0: SQLite

Install sqlite.


Step 1: RVM

Make a multi-user RVM installation as specified here.


# usermod -a -G rvm http
# usermod -a -G rvm nobody



Step 2: Rubies

Once you have a working RVM installation in your hands, it is time to install the latest Ruby interpreter

Note: During the installation of Ruby patches will be applied. Consider installing the base-devel group beforehand.
$ rvm install 2.0.0
Note: It may be useful to delete the 'global' gemsets of the environments that have web applications. Their gems might somehow interfere with Passenger. In that case, a rvm 2.0.0 do gemset delete global is sufficient.

Step 3: Nginx with Passenger support

Run the following to allow passenger install nginx:

$ rvm use 2.0.0 
$ gem install passenger
$ rvmsudo passenger-install-nginx-module

The passenger gem will be put into the default gemset.

This will download the sources of Nginx, compile and install it for you. It will guide you through all the process. Note that the default location for Nginx will be /opt/nginx.


After completion, add the following two lines into the 'http block' at /opt/nginx/conf/nginx.conf that look like:

http { 
  passenger_root /usr/local/rvm/gems/ruby-2.0.0-p353/gems/passenger-3.0.9;
  passenger_ruby /usr/local/rvm/wrappers/ruby-2.0.0-p353/ruby;
Note: This step is currently being done automatically by the installer script.

Step 4: Gemsets and Apps


Install RefineryCMS first:

$ rvm use 2.0.0@refinery --create
$ gem install rails -v 4.0.1
$ gem install passenger
$ gem install refinerycms refinerycms-i18n sqlite3

Deploy a RefineryCMS instance called refineria:

$ cd /srv/http/
$ rvmsudo refinerycms refineria

Install BrowserCMS in a different gemset:

$ rvm use 2.0.0@browser --create
$ gem install rails -v 4.0.1
$ gem install passenger
$ gem install browsercms sqlite3

Deploy a BrowserCMS instance called navegador:

$ cd /srv/http/
$ rvmsudo browsercms demo navegador
$ cd /srv/http/navegador
$ rvmsudo rake db:install

Passenger for Nginx and Passenger Standalone


  • 2.0.0 => for Nginx,
  • 2.0.0@refinery => Standalone
  • 2.0.0@browser => Standalone

The strategy is to combine Passenger for Nginx with Passenger Standalone. One must first identify the Ruby environment (interpreter plus gemset) that one uses the most; in this setup the Ruby interpreter and the default gemset were selected. One then proceeds with setting up Passenger for Nginx to use that environment (step 3).


Step 5: .rvmrc files and ownerships


rvm <ruby_version>@<gemset_name>


Create /srv/http/refineria/.rvmrc doing


, and /srv/http/navegador/.rvmrc with



These files aid the programs involved to find the correct gems.



Step 6: Reverse proxies


$ cd /srv/http/refineria


$ cd /srv/http/navegador



rvmsudo passenger start -a -p 3000 -d

Launch Passenger Standalone daemons at system start-up

Do you have a script? Please post it here.

The systemd script below was made for a Typo blog I host at /srv/http/typo. It is located at /etc/systemd/system/passenger_typo.service. I set the Environment= tags (see "man systemd.exec") from the output of "rvm env". The only exception was PATH=, which I had to combine from my regular PATH and the output of rvm env.

Note: If you do not set the "WorkingDirectory=" variable to your application folder, passenger will fail to find your app and will subsequently shut itself down.

Description=Passenger Standalone Script for Typo





Step 7: Deployment

With subdomains


## RefineryCMS ##

server {
    root /srv/http/refineria/public;
    location / {
        proxy_set_header Host $host;

## BrowserCMS ##

server {
    root /srv/http/navegador/public;
    location / {
        proxy_set_header Host $host;

Without subdomains

If you for some reason do not want to host each application on its own subdomain but rather in a url like: then you could do something like this in your config:

server {
    #Base for the html files etc
    root /srv/http/;

    #First application you want hosted under domain
    location /railsapp {
        root /srv/http/railsapp/public;
        #passenger_base_uri /railsapp;
        #but probably only if you are using the other solution with passenger phusion
        proxy_set_header Host $host;

    #Second applicatino you want hosted under domain
    location /anotherapp {
        root /srv/http/anotherapp/public;
        proxy_set_header Host $host;

At this point you are in conditions to start the nginx service and to access both CMSs through and


See also