April 2011

require 'rubygems'
require 'rake/rpmtask'
require 'rake/yumtask'
 
CURRENT_DIR  = File.dirname(__FILE__)
YUM_REPO     = "#{CURRENT_DIR}/repo"
RPM_SPEC     = "my-package.spec"
 
# Build the rpm
rpm_task =
Rake::RpmTask.new(RPM_SPEC) do |rpm|
  rpm.need_tar = true
  rpm.package_files.include("bin/*", "recipes/**/*")
  rpm.topdir = "#{RPMBUILD_DIR}"
end
 
# Construct yum repo
Rake::YumTask.new(YUM_REPO) do |repo|
  repo.rpms << rpm_task.rpm_file
end

# Define a package task library to aid in the definition of RPM
# packages.
 
require 'rubygems'
require 'rake'
require 'rake/packagetask'
 
require 'rbconfig' # used to get system arch
 
module Rake
 
  # Create a package based upon a RPM spec.
  # RPM packages, can be produced by this task.
  class RpmTask < PackageTask
    # RPM spec containing the metadata for this package
    attr_accessor :rpm_spec
 
    # RPM build dir
    attr_accessor :topdir
 
    # Include extra_release information in the rpm
    attr_accessor :include_extra_release
 
    def initialize(rpm_spec)
      init(rpm_spec)
      yield self if block_given?
      define if block_given?
    end
 
    def init(rpm_spec)
      @include_extra_release = true
      @rpm_spec = rpm_spec
 
      # parse this out of the rpmbuild macros,
      # not ideal but better than hardcoding this
      File.open('/etc/rpm/macros.dist', "r") { |f|
        f.read.scan(/%dist\s*\.(.*)\n/)
        @distro = $1
      }
 
      # Parse rpm name / version out of spec
      # hacky way to do this for now
      #   (would be nice to implement a full blown rpm spec parser for ruby)
      File.open(rpm_spec, "r") { |f|
        contents = f.read
        @name    = contents.scan(/\nName: .*\n/).first.split.last
        @version = contents.scan(/\nVersion: .*\n/).first.split.last
        @release = contents.scan(/\nRelease: .*\n/).first.split.last
        @release.gsub!("%{?dist}", ".#{@distro}")
        @arch    =  contents.scan(/\nBuildArch: .*\n/) # TODO grab local arch if not defined
        if @arch.nil?
          @arch = Config::CONFIG["target_cpu"] # hoping this will work for all cases,
                                               # can just run the 'arch' cmd if we want
        else
          @arch = @arch.first.split.last
        end
      }
      super(@name, @version)
 
      @rpmbuild_cmd = 'rpmbuild'
    end
 
    def define
      super
 
      directory "#{@topdir}/SOURCES"
      directory "#{@topdir}/SPECS"
 
      desc "Build the rpms"
      task :rpms, [:include_extra_release] => [rpm_file]
 
      # FIXME properly determine :package build artifact(s) to copy to sources dir
      file rpm_file, [:include_extra_release] => [:package, "#{@topdir}/SOURCES", "#{@topdir}/SPECS"] do |t,args|
        @include_extra_release = args.include_extra_release != "false"
        git_head = `git log -1 --pretty=format:%h`
        extra_release = "." + Time.now.strftime("%Y%m%d%k%M%S").gsub(/\s/, '') + "git" + "#{git_head}"
        cp "#{package_dir}/#{@name}-#{@version}.tgz", "#{@topdir}/SOURCES/"
        cp @rpm_spec, "#{@topdir}/SPECS"
        sh "#{@rpmbuild_cmd} " +
           "--define '_topdir #{@topdir}' " +
           "--define 'extra_release #{@include_extra_release ? extra_release : ''}' " +
           "-ba #{@rpm_spec}"
      end
    end
 
    def rpm_file
      # at some point we should support all a spec's subpackages as well
      "#{@topdir}/RPMS/#{@arch}/#{@name}-#{@version}-#{@release}.#{@arch}.rpm"
    end
  end
end

# Define a package task library to aid in the definition of YUM
# repos.
 
require 'rubygems'
require 'rake'
 
module Rake
 
  # Create a yum repo with specified rpms
  class YumTask < TaskLib
    # Yum repository location which to build
    attr_accessor :yum_repo
 
    # RPMs to pull into yum repo
    attr_accessor :rpms
 
    def initialize(yum_repo)
      init(yum_repo)
      yield self if block_given?
      define if block_given?
    end
 
    def init(yum_repo)
      @yum_repo = yum_repo
      @createrepo_cmd = 'createrepo'
      @rpms = []
    end
 
    def define
      desc "Build the yum repo"
      task :create_repo => @rpms do
        @rpms.each { |rpm|
          rpmc = rpm.split('.')
          arch = rpmc[rpmc.size-2]
          arch_dir = @yum_repo + "/" + arch
          FileUtils.mkdir_p arch_dir unless File.directory? arch_dir
          cp_r rpm, "#{@yum_repo}/#{arch}"
        }
        sh "#{@createrepo_cmd} -v #{@yum_repo}"
      end
    end
  end
end