Question

I used to be a .NET guy, and enjoyed using a nightly build system (continuous integration) called CruiseControl.NET to automatically deploy my applications to my staging environment each night.

Now that I’ve made the jump to Ruby on Rails and GitHub, I’ve found myself a little confused about how to setup an equivalent automated, nightly build system. I want to do things right, the Rails way, but I could use a push in the right direction.

Here’s what I’m using…

• Ruby on Rails 3.2.9 (with asset pipeline)
• RVM
• Apache + Passenger
• MySQL
• Ubuntu 12.04 (staging server OS)
• GitHub (SCM)

I’m looking for a system/solution that fulfills these requirements: (Ideally utilizing Capistrano…)

• Deploy the latest commit from my ‘master’ branch in my GitHub repository to my staging server.
• One-click build on-demand: I want to click a button or link to force a deploy (or re-deploy) at any time
• Have the capability to run custom commands on the staging server as a part of the deploy (i.e. ‘bundle install’, restart Apache, etc…)
• Automatic deploy daily or after a commit on GitHub (optional)

And because I’d never ask this question without doing some research first, here are some relevant resources I’ve found, but haven’t been able to decipher:

• Automatic Deployment via Git
• Deploying Rails 3 apps with Capistrano

Suggestions, anyone? Thanks!

• David

Answer 1

Well, it turns out there is alot of good information out there regarding how to use Capistrano for this purpose (including Prakash’s reference), but none of it seems to be fully comprehensive.

After many hours of picking through guide, after forum, after stack overflow question, I managed to fulfill most of my goals. To save time for others, I will try to provide answers and information that I found in the context of my original question.

---

UPDATE:

It turns out I was looking for Jenkins all along: it’s a perfect (an even an improved) analog to the CruiseControl build server application I had used before. Jenkins is a web application that kicks off builds on a scheduled basis or, with plugins, commit events. It doesn’t include functionality to actually deploy my Rails app, so that’s where Capistrano steps in. Using Jenkins’ “shell execute” build task to trigger Capistrano deploys, I was able to accomplish all of my goals above.

Take a look at this guide for more detail.

---

ORIGINAL POST:

First off, Capistrano can work for the purpose of build system, however, it is not at all similar to CruiseControl.

CruiseControl is:

• A web application, that is run on a machine that serves as a ‘build server’
• Any user may visit the web app to run builds; the user does not have to have anything setup or configured on their end… it’s just a webpage.
• The interface also provides functions for logs, blame, scheduled builds, etc…

Capistrano is:

• Not an application or service, but a gem that works like rake; it bears similar functionality to the Ant and Nant scripts used by CruiseControl for the purpose of deploying.
• Capistrano is run on a user’s local machine (typically the Rails app folder), and requires configuration on their end to run
• It directly connects from the user’s machine to the remote server via SSH to perform deploys (this may not be preferable if you don’t want to grant users SSH access to the remote server)
• Commands are run through a console i.e. cap deploy (this is as close as it gets to ‘one click’ deploys.)
• It does produce logs, perform rollbacks etc.
• It does not kick-off scheduled builds on its own (using cron was suggested)

In regards to my original requirements…

Deploy the latest commit from my ‘master’ branch in my GitHub repository to my staging server.

Configuring Capistrano’s deploy.rb file will accomplish this.

One-click build on-demand: I want to click a button or link to force a deploy (or re-deploy) at any time

All Capistrano deploys are done through ‘force’: you run ‘cap deploy’ in your console manually

Have the capability to run custom commands on the staging server as a part of the deploy (i.e. ‘bundle install’, restart Apache, etc…)

Configuring Capistrano’s deploy.rb file will accomplish this. Most of these commands are included out of the box.

Automatic deploy daily or after a commit on GitHub (optional)

I haven’t figured this one out yet… a cron job might be the best way to do this.

Setting up Capistrano

Start with this tutorial from GitHub first. In your Rails App folder, you should end up with a Capfile and config/deploy.rb file.

To save you some time, copy and paste these files, and tweak the settings to your needs.
The files below are configured for:

• Deployment to a test environment
• GitHub
• RVM based Rails
• Using an explicit version of Ruby and gemset
• Including untracked files (i.e. a database.yml file you didn’t commit to SCM)
• Using Rails asset pipeline
• Running migrate and seed with each deploy
• Restarting Apache based Passenger with each deploy

Capfile

# Set this if you use a particular version of Ruby or Gemset
set :rvm_ruby_string, 'ruby-1.9.3-p286@global'
#set :rvm_ruby_string, ENV['GEM_HOME'].gsub(/.*\//,"") # Read from local system

require "bundler/capistrano"
# Uncomment this if you're using RVM
require "rvm/capistrano"

load 'deploy'
# Uncomment if you are using Rails' asset pipeline
load 'deploy/assets'
load 'config/deploy' # remove this line to skip loading any of the default tasks

config/deploy.rb

# BEGIN RUBY CONFIG
# You can manually override path variables here
# set :default_environment, {
#     'PATH' => "/usr/local/bin:/bin:/usr/bin:/bin:/<ruby-dir>/bin",
#     'GEM_HOME' => '<ruby-dir>/lib/ruby/gems/1.8',
#     'GEM_PATH' => '<ruby-dir>lib/ruby/gems/1.8',
#     'BUNDLE_PATH' => '<ruby-dir>/lib/ruby/gems/1.8/gems'  
# }
# This changes the default RVM bin path
# set :rvm_bin_path, "~/bin"

# If your remote server doesn't have a ~/.rvm directory, but is installed
# at the /usr/local/rvm path instead, use this line
set :rvm_type, :system
# END RUBY CONFIG

default_run_options[:pty] = true  # Must be set for the password prompt
                                  # from git to work

# BEGIN MULTIPLE ENVIRONMENT DEPLOYS
# Read the following URL if you need to deploy to different environments (test, development, etc)
# https://github.com/capistrano/capistrano/wiki/2.x-Multistage-Extension
# set :stages, %w(production test)
# set :default_stage, "test"
# require 'capistrano/ext/multistage'
# END MULTIPLE ENVIRONMENT DEPLOYS

# BEGIN APPLICATION VARS
set :application, "yourapp"
set :rails_env, 'test'
# END APPLICATION VARS

# BEGIN PATH DEFINITIONS
set(:releases_path)     { File.join(deploy_to, version_dir) }
set(:shared_path)       { File.join(deploy_to, shared_dir) }
set(:current_path)      { File.join(deploy_to, current_dir) }
set(:release_path)      { File.join(releases_path, release_name) }
# END PATH DEFINITIONS

# BEGIN SCM VARS
set :repository, "[e-mail]:yourgithubuser/yourrepository.git"  # Your clone URL
set :scm, "git"
set :scm_username, "yourgithubuser"
set :scm_password, proc{Capistrano::CLI.password_prompt('GitHub password:')}  # The deploy user's password
set :branch, "master"
# END SCM VARS


# BEGIN SERVER VARS
set :user, "ubuntu"  # The server's user for deploys
role :web, "dev.#{application}" # The location of your web server i.e. dev.myapp.com
role :app, "dev.#{application}" # The location of your app server i.e. dev.myapp.com
role :db, "dev.#{application}", :primary => true  # The location of your DB server i.e. dev.myapp.com

set :deploy_to, "/home/#{user}/www/#{application}"
set :deploy_via, :remote_cache
# Uncomment this if you want to store your Git SSH keys locally and forward
# Else, it uses keys in the remote server's .ssh directory
# ssh_options[:forward_agent] = true
# END SERVER VARS

# BEGIN ADDITIONAL TASKS
before "deploy:start" do
  deploy.migrate
  deploy.seed
end

before "deploy:restart" do
  deploy.migrate
  deploy.seed
end

# Some files that the Rails app needs are too sensitive to store in SCM
# Instead, manually upload these files to your <Rails app>/shared folder
# then the following code can be used to generate symbolic links to them,
# so that your rails app may use them.
# In this example below, I link 'shared/config/database.yml' and 'shared/db/seed_data/moderators.csv'
before "deploy:assets:precompile" do
  run ["ln -nfs #{shared_path}/config/settings.yml #{release_path}/config/settings.yml",
       "ln -nfs #{shared_path}/config/database.yml #{release_path}/config/database.yml",
       "mkdir -p #{release_path}/db/seed_data",
       "ln -nfs #{shared_path}/db/seed_data/moderators.csv #{release_path}/db/seed_data/moderators.csv",
       "ln -fs #{shared_path}/uploads #{release_path}/uploads"
  ].join(" && ")
end

namespace :deploy do
  # Define seed task (call 'cap deploy:seed')
  desc "Reload the database with seed data"
  task :seed do
    run "cd #{current_path}; bundle exec rake db:seed RAILS_ENV=#{rails_env}"
  end

  # If you are using Passenger mod_rails uncomment this:
  task :start do ; end
  task :stop do ; end
  task :restart, :roles => :app, :except => { :no_release => true } do
    run "#{try_sudo} touch #{File.join(current_path,'tmp','restart.txt')}"
  end
end
# END ADDITIONAL TASKS