Capistrano: Drupal deployments made easy, Part 1

gem install capistrano
gem install capistrano-ext

|-- capfile
|-- config
|   |-- deploy
|   |   |-- development.rb
|   |   `-- production.rb
|   `-- deploy.rb
`-- drupal
    `-- index.php

|-- current -> /var/www/releases/20091023202918
|-- releases
|   |-- 20091023191450
|   `-- 20091023202918
`-- shared
    |-- cached-copy
    |-- default
    |   |-- files
    |   `-- local_settings.php
    `-- system

### This file contains project-specific settings ###
 
# The project name.
set :application, "myproject"
 
# List the Drupal multi-site folders.  Use "default" if no multi-sites are installed.
set :domains, ["default"]
 
# Set the repository type and location to deploy from.
set :scm, :subversion
set :repository,  "https://example.com/trunk/drupal"
 
# Use a remote cache to speed things up
set :deploy_via, :remote_cache
 
# Multistage support - see config/deploy/[STAGE].rb for specific configs
set :default_stage, "development"
set :stages, %w(production development)
 
# Generally don't need sudo for this deploy setup
set :use_sudo, false

### This file contains stage-specific settings ###
 
# Set the deployment directory on the target hosts.
set :deploy_to, "/var/www/#{application}"
 
# The hostnames to deploy to.
role :web, "devel.example.com"
 
# Specify one of the web servers to use for database backups or updates.
# This server should also be running Drupal.
role :db, "devel.example.com", :primary => true
 
# The username on the target system, if different from your local username
# ssh_options[:user] = 'alice'
 
# The path to drush
set :drush, "cd #{current_path} ; /usr/bin/php /data/lib/php/drush/drush.php"

load 'deploy' if respond_to?(:namespace) # cap2 differentiator
Dir['vendor/plugins/*/recipes/*.rb'].each { |plugin| load(plugin) }
load 'config/deploy.rb'
 
require 'capistrano/ext/multistage'
 
namespace :deploy do
 
  # Overwritten to provide flexibility for people who aren't using Rails.
  desc "Prepares one or more servers for deployment."
  task :setup, :except => { :no_release => true } do
    dirs = [deploy_to, releases_path, shared_path]
    domains.each do |domain|
      dirs += [shared_path + "/#{domain}/files"]
    end
    dirs += %w(system).map { |d| File.join(shared_path, d) }
    run "umask 02 && mkdir -p #{dirs.join(' ')}" 
  end
 
  desc "Create settings.php in shared/config" 
  task :after_setup do
    configuration = <<-EOF
<?php
$db_url = 'mysql://username:password@localhost/databasename';
$db_prefix = '';
EOF
    domains.each do |domain|
      put configuration, "#{deploy_to}/#{shared_dir}/#{domain}/local_settings.php"
    end
  end
 
  desc "link file dirs" 
  task :after_update_code do
    domains.each do |domain|
    # link settings file
      run "ln -nfs #{deploy_to}/#{shared_dir}/#{domain}/local_settings.php #{release_path}/sites/#{domain}/local_settings.php"
      # remove any link or directory that was exported from SCM, and link to remote Drupal filesystem
      run "rm -rf #{release_path}/sites/#{domain}/files"
      run "ln -nfs #{deploy_to}/#{shared_dir}/#{domain}/files #{release_path}/sites/#{domain}/files"
    end
  end
 
  # desc '[internal] Touches up the released code.'
  task :finalize_update, :except => { :no_release => true } do
    run "chmod -R g+w #{release_path}"
  end
 
  desc "Flush the Drupal cache system."
  task :cacheclear, :roles => :db, :only => { :primary => true } do
    domains.each do |domain|
      run "#{drush} --uri=#{domain} cache clear"
    end    
  end
 
  namespace :web do
    desc "Set Drupal maintainance mode to online."
    task :enable do
      domains.each do |domain|
        php = 'variable_set("site_offline", FALSE)'
        run "#{drush} --uri=#{domain} eval '#{php}'"
      end
    end
 
    desc "Set Drupal maintainance mode to off-line."
    task :disable do
      domains.each do |domain|
        php = 'variable_set("site_offline", TRUE)'
        run "#{drush} --uri=#{domain} eval '#{php}'"
      end
    end
  end
 
  after "deploy", "deploy:cacheclear"
  after "deploy", "deploy:cleanup"
 
 
  # Each of the following tasks are Rails specific. They're removed.
  task :migrate do
  end
 
  task :migrations do
  end
 
  task :cold do
  end
 
  task :start do
  end
 
  task :stop do
  end
 
  task :restart do
  end
 
end
 
 
desc "Download a backup of the database(s) from the given stage."
task :download_db, :roles => :db, :only => { :primary => true } do
  domains.each do |domain|
    filename = "#{domain}_#{stage}.sql"
    run "#{drush} --uri=#{domain} sql dump --structure-tables-key=common > ~/#{filename}"
    download("~/#{filename}", "db/#{filename}", :via=> :scp)
  end
end