Rakefile example

1-readme.md

This example splits namespaces into different files, but that's likely overkill for most uses. Shoving everything in a Rakefile would work fine too.

To use this:

cd /tmp
mkdir raketest
cd raketest
touch Rakefile
mkdir rakelib
# save the two sample *.rake files in rakelib

In this example, a blank Rakefile is fine; it provides an 'anchor' so rake can find the root of the 'project'. Rake will then find and autoload rakelib/*.rake files to load tasks.

Invoke via rake packer:release[baseboxname]

In the tasks, the :basebox parameter is accessible as args.basebox. In the task's sh block, use normal hash+curlies interpolation: #{args.basebox}

packer.rake

require "pathname"

packer_binary_dir = Pathname.new("~/software/packer/current")
packer_template_basedir = Pathname.new("~/code/packer")

namespace :packer do

  # this is the published/preferred task to use; it has a 'desc' description command
  # and will appear in rake -T
  desc "Build, upload and clean"
  task :release, [:basebox] => [:build, :upload, :clean, "vagrant:basebox:remove"]

  # this is an 'internal' task, not meant to be invoked directly as part of normal use.
  # As such, there's no description and it won't appear in rake -T
  task :build, [:basebox] do |t, args|
    sh <<-CMD
      set -o errexit
      set -o nounset
      PATH=#{packer_binary_dir}:$PATH
      cd #{packer_template_basedir}/#{args.basebox}
      packer build template.json
    CMD
  end

  task :upload, [:basebox] do |t, args|
    sh <<-CMD
      set -o errexit
      set -o nounset
      cd #{packer_template_basedir}/#{args.basebox}
      scp packer*.box user@host:/directory/
    CMD
  end

  task :clean, [:basebox] do |t, args|
    sh <<-CMD
      set -o errexit
      set -o nounset
      cd #{packer_template_basedir}/#{args.basebox}
      rm -r packer_cache packer*.box
    CMD
  end
end

vagrant.rake

namespace :vagrant do
  namespace :basebox do
    task :remove, [:basebox] do |t, args|
      sh <<-CMD
        vagrant box remove #{args.basebox} || true
      CMD
    end
  end
end