Gluttonous

##############################################################################
# Deploy
##############################################################################

begin
  require 'rake_remote_task'

  APP_NAME = "someapp"
  DEPLOY_ROOT = "/usr/local/share/applications/#{APP_NAME}"
  ON_DEPLOY_RESTART = ["someappd"]

  role :app_server, "myserver.com"

  def archive
    commit = `git-rev-list --max-count=1 --abbrev=10 --abbrev-commit HEAD`.chomp
    file = "#{APP_NAME}-#{commit}.tar.gz"
  end

  def restart_daemons
    ON_DEPLOY_RESTART.each do |app|
      run "sudo god restart #{app}"
    end
  end

  namespace :deploy do
    task :build do
      sh "git archive --format=tar HEAD | gzip > #{archive}"
    end

    remote_task :push => :build do
      rsync archive, "/tmp"
    end

    desc "Install a release from the latest commit"
    remote_task :install => :push do
      date_stamp = Time.now.strftime("%Y%m%d")
      last_release = run("ls #{DEPLOY_ROOT}/rels | sort -r | head -n 1").chomp

      if last_release =~ /#{date_stamp}\-(\d+)/
        serial = $1.to_i + 1
      else
        serial = 0 
      end

      rel = ("%d-%02d" % [date_stamp, serial])
      rel_dir = "#{DEPLOY_ROOT}/rels/#{rel}"

      run "sudo mkdir -p #{rel_dir}"
      run "sudo tar -xzvf /tmp/#{archive} -C #{rel_dir} && rm -rf /tmp/#{archive}"
      run "sudo ln -s -f -T #{rel_dir} #{DEPLOY_ROOT}/current"
      restart_daemons
    end

    desc "Rollback to the previous release"
    remote_task :rollback do
      current_link = run("ls -alF #{DEPLOY_ROOT} | awk '/current -> .*/ { print $NF }'").chomp
      current = File.basename(current_link)
      releases = run("ls #{DEPLOY_ROOT}/rels | sort -r").split("\n")
      previous = releases.find {|rel| current > rel}
      raise "No previous release" if previous.nil?
      run "sudo ln -s -f -T #{DEPLOY_ROOT}/rels/#{previous} #{DEPLOY_ROOT}/current"
      restart_daemons
      puts "Moved to #{previous}"
    end

    desc "Rollforward to the next release"
    remote_task :rollforward do
      current_link = run("ls -alF #{DEPLOY_ROOT} | awk '/current -> .*/ { print $NF }'").chomp
      current = File.basename(current_link)
      releases = run("ls #{DEPLOY_ROOT}/rels | sort -r").split("\n")
      next_rel = releases.find {|rel| current < rel}
      raise "No next release" if next_rel.nil?
      run "sudo ln -s -f -T #{DEPLOY_ROOT}/rels/#{next_rel} #{DEPLOY_ROOT}/current"
      restart_daemons
      puts "Moved to #{next_rel}"
    end
  end
rescue LoadError => e
  puts "NOTE: Install vlad to get Kevin's awesome deployment tasks"
end

Odysseus:ext kev$ sudo -s
bash-3.2# ARCHFLAGS='-arch i386' gem install postgres
Building native extensions.  This could take a while...
Successfully installed postgres-0.7.9.2007.12.22
Installing ri documentation for postgres-0.7.9.2007.12.22...
Installing RDoc documentation for postgres-0.7.9.2007.12.22...

class TreeNode
  attr_reader :name

  def initialize(name)
    @name = name
    @children = []
  end

  def add_node(node)
    @children << node
  end

  def each_depth_first
    @children.each do |child|
      child.each_depth_first do |c|
        yield c
      end
    end

    yield self
  end
end

# root  -  a  -  b
#   \       \ 
#    e - f   c  -  d
#     \
#      g

root = TreeNode.new("root")
root.add_node( a = TreeNode.new("a"))
a.add_node( b = TreeNode.new("b"))
a.add_node( c = TreeNode.new("c"))
c.add_node( d = TreeNode.new("d"))
root.add_node(e = TreeNode.new("e"))
e.add_node(f = TreeNode.new("f"))
e.add_node(g = TreeNode.new("g"))

root.each_depth_first do |child|
  puts child.name
end

# produces:
# b
# d
# c
# a
# f
# g
# e
# root

require "test/unit"
require 'rubygems'
require 'mocha'
require 'stubba'

module ForwardsToEnumerable
  def self.included(klass)
    klass.extend(ClassMethods)
  end

  module ClassMethods
    def forward_to_enum(instance_var, *meths)
      meths.each do |meth|
        class_eval <<-METH
          def #{meth}(*args, &block)
            #{instance_var.to_s}.each do |i|
              i.send(:#{meth}, *args, &block)
            end
          end
        METH
      end
    end
  end

end

class ForwardsToArray
  include ForwardsToEnumerable
  forward_to_enum :@array, :foo, :bar, :baz

  def initialize(array)
    @array = array
  end
end

class TestForwardsToArray < Test::Unit::TestCase
  def test_forward_to_enum
    items = [mock(), mock(), mock()]
    items.each {|i| i.expects(:foo); i.expects(:bar); i.expects(:baz) }
    f = ForwardsToArray.new(items)
    f.foo
    f.bar
    f.baz
  end
end

# Equivalent to rpmvercmp in librpm, eccentricities and all
def <=>(other)
  return 0 if self.version == other.version and self.rel == other.rel

  versions = self.version.split(/[^[:alnum:]]/).push self.rel
  other_versions = other.version.split(/[^[:alnum:]]/).push other.rel

  return  1 if versions.size > other_versions.size
  return -1 if versions.size < other_versions.size

  versions.size.times do |n|
    if versions[n] =~ /[^\d]/ && other_versions[n] =~ /[^\d]/
      comparison = (versions[n] <=> other_versions[n])
    elsif versions[n] !~ /[^\d]/ && other_versions[n] !~ /[^\d]/
      comparison = (versions[n].to_i <=> other_versions[n].to_i)
    else
      comparison = -1
    end
    return comparison unless comparison.zero?
  end

  return 0 
end

require 'yaml'
require 'pp'
pp YAML.load(`svn info`) # =>
# {"Node Kind"=>"directory",
#  "Last Changed Author"=>"nzkoz",
#  "URL"=>"http://dev.rubyonrails.org/svn/rails/trunk",
#  "Schedule"=>"normal",
#  "Last Changed Rev"=>7332,
#  "Repository UUID"=>"5ecf4fe2-1ee6-0310-87b1-e25e094e27de",
#  "Repository Root"=>"http://dev.rubyonrails.org/svn/rails",
#  "Last Changed Date"=>"2007-08-16 18:11:11 -0700 (Thu, 16 Aug 2007)",
#  "Revision"=>7340,
#  "Path"=>"."}