A cap 'stage' for dynamic deploy of feature branch demos

gistfile1.rb

# An experiment for a capistrano 'stage' that can actually be used to
# deploy multiple feature branches at once. 

# Intended to be installed config/deploy/feature_demo , when using cap
# multi-stage support: add 'feature_demo' to 'stages' in `config/deploy.rb` too.

# Run from a git feature branch `cap feature_demo deploy` to deploy to
# single machine we have all our feature demos on.  

# Name of feature branch will be taken from current git checkout. 

# Will be deployed to /opt/feature_demos/name_of_feature, from
# git branch name_of_feature, AND an httpd conf will be created telling
# passenger to deploy that app, woo. 
#
#     cap feature_demo deploy
#
# You WILL need to manually restart apache if this is the first time
# you've deployed that feature demo. 
#
# If you want to deploy a different branch than your current checkout:
#
#     cap feature_demo deploy -S branch=some_branch
#
# If you want to reference the deployed feature by something other than
# branch name:
#
#     cap feature_demo deploy -S feature=something_else 
#
# feature name is used for directory path of checkout, Apache 
# subUri, etc. shouldn't have spaces, should be a nice token. 
#
#
# If you are done with a feature demo and want to wipe it from disk etc,
#     cap feature_demo deploy:cleanup_feature_demo
#
#  (Have to use `feature` or `branch` args matching how you created it)




# not using any of our special roles for cronjobs, for a feature
# demo we just want a basic app deploy. 
server "demo.server.tld", :app, :web

unless exists? :branch
  set :branch do         
    branch = `git symbolic-ref -q HEAD`.sub(%r{^refs/heads/}, '').chomp  
    raise CommandError.new("feature_demo cap stage only works if you have a checked out feature branch!") if branch == "master"  
    branch
  end
end


unless exists? :feature
  set(:feature) { fetch :branch }
end
  
  

# have to tell it the SubURI we'll be deploying at for asset
# precompilation. 
set :asset_env, "#{asset_env} RAILS_RELATIVE_URL_ROOT=/#{feature}"

set :deploy_to, "/opt/feature_demos/#{feature}" 

# I can never get capistrano sudo to work anyway, all places
# we're going to write to just need to be writeable by the user
set :use_sudo, false

# We have a 'demo' Rails environment defined, which has config settings
# very production-like, but uses non-production database and other external
# APIs. 
set :rails_env, "demo"
 
# For rvm-ified machine on blacklight.library
require 'rvm/capistrano'
set :rvm_ruby_string, '1.9.3' 


# No reason to keep old releases in our feature_demo checkouts
set :keep_releases, 1


set(:webroot, "/var/www/html") unless exists? :webroot
set(:apache_conf_dir, "/etc/httpd/conf.d") unless exists? :apache_conf_dir

unless exists? :apache_conf_file
  set(:apache_conf_file_path) { File.join(apache_conf_dir, "#{feature}.conf") }
end

namespace :deploy do
  task :passenger_apache_conf, :roles => [:web] do
    
    apache_conf = <<-EOS
      RackBaseURI /#{feature}
      <Directory #{deploy_to}>
        RailsEnv #{rails_env}
        Options -MultiViews
      </Directory>
    EOS
    
    put apache_conf, apache_conf_file_path  
  end
  
  task :passenger_symlink, :roles => [:web] do
    run "ln -sf #{File.join(deploy_to, "current", "public")} #{File.join(webroot, feature)}"
  end
  
end

before "deploy:restart", "deploy:passenger_symlink", "deploy:passenger_apache_conf"

# Want to clean up a feature branch?
# cap deploy:cleanup_feature_demo

namespace :deploy do
  task :cleanup_feature_demo, :roles => [:web] do
    run "rm -rf #{deploy_to}"
    run "rm -rf #{File.join(webroot, feature)}"
    run "rm -rf #{File.join(apache_conf_dir, "#{feature}.conf")}"
  end
end