post-receive-script

#!/usr/bin/env ruby

# One idea:
# Use pre-receive. Exit with a non-zero status to abort and not allow data to be committed.
# The git repo is not where the app is. So, what we want to do is check out the app to some sandbox location and try to run it on a sandboxed port.
# If this succeeds, allow the commit. If not, disallow the commit and abort the push. In the meantime, we can also print some nice status lines.

# Simple method:
# Use post-receive. Check out the repo into an executable location (/home/dcparker/apps), create configs if necessary and activate it.

require 'yaml'

# Starts with defaults (hash), updates with what's currently in the file, then rewrites the file.
def YAML.write_defaults_to_file(file, defaults)
  from_yaml = File.exists?(file) ? (YAML.load_file(file) || {}) : {}
  defaults.update(from_yaml)
  File.open(file, 'w') do |yaml_file|
    yaml_file << defaults.to_yaml
  end
end

domain = ARGV[0]
app_dir = "/home/git/apps/#{domain}"
puts "In #{domain}..."

# if app is not there, create it; otherwise update it
if File.exists?(app_dir)
  puts "Updating application..."
  Dir.chdir(app_dir)
  latest_commit = `git log -n 1 |grep -E -o "\\w{40}$"`.chomp

  # Read old cilantro config
  cilantro_config = nil
  if File.exists?("/home/git/apps/#{domain}/config/production.yml")
    cilantro_config = YAML.load_file("/home/git/apps/#{domain}/config/production.yml") || {}
  end

  system("rm config/production.yml")
  system("git --git-dir=.git checkout -- config/production.yml")
  system("git --git-dir=.git pull")

  # Integrate new config data and rewrite file
  YAML.write_defaults_to_file("/home/git/apps/#{domain}/config/production.yml", cilantro_config)
else
  puts "Creating application..."
  system("git clone /home/git/repositories/#{domain}.git #{app_dir}")
  Dir.chdir(app_dir)
  system("mkdir log")
  system("chmod 777 log")
  YAML.write_defaults_to_file("/home/git/apps/#{domain}/config/production.yml", YAML.load_file("/home/git/defaults/production.yml"))
end
system("echo production > RACK_ENV")

ENV['GIT_DIR'] = "/home/git/repositories/#{domain}.git"
if latest_commit
  commits_included_gems = !!(`git whatchanged #{latest_commit ? latest_commit+'..HEAD ' : ''}| grep -E "\\W+(?:M|A)\\W+.gems"`.chomp =~ /\.gems/)
  commits_included_migration = !!(`git whatchanged #{latest_commit ? latest_commit+'..HEAD ' : ''}| grep -E "\\<A\\>\\W+\\<config/migrations"`.chomp =~ /config\/migrations\/.+\.rb/)
else
  commits_included_gems = commits_included_migration = true
end

# if site configs don't exist, create them; otherwise just restart the app
puts "Activating the application..."
if `sudo site list` =~ /#{domain}/
  # Update and restart the app
  system("sudo site activate #{domain} --no-start")
  if commits_included_gems
    puts "Installing new gems..."
    system("rake gems:refresh:production")
  end
  if commits_included_migration
    puts "Migrating the database..."
    system("rake db:migrate:up")
  end
  puts "Restarting the application..."
  system("sudo site restart #{domain}")
else
  # Create and activate the app if it doesn't exist
  system("sudo site new #{domain}")
  system("sudo site activate #{domain} --no-start")
  if commits_included_migration
    puts "Migrating the database..."
    system("rake db:migrate:up")
  end
  puts "Starting the application..."
  system("sudo site start #{domain}")
end