create_install_gemset

#!/usr/bin/env ruby
##########################################
###
##  File: create_install_getset
##  Desc: Builds an executable file to reinstall the gemset taken
##        into account the different gem dependencies.
##
##  NOTE: Using shell script with 'rvm gemset create/use' and
##        'gem install' rather than creating a Gemfile and using
##        bundler because in my environment I keep at least one
##        gemset that has several hundred gems which I have declared
##        worthy to use.  Bundler just can't handle that large a
##        number.
#

require 'pathname'
require 'date'

$gem_hash = Hash.new
$gem_names= Array.new

Gem::Specification.all.each do |gs|
  # ignore duplicates - they are just different versions of the same thing
  $gem_names << gs.name unless $gem_names.include?(gs.name)
  $gem_hash[gs.name] = gs
end



def do_it

  $gem_names.each do |g|

    next if g.nil?

    gd = $gem_hash[g].dependencies.map {|d| d.name}

    gd.each do |gg|
      x = $gem_names.index(gg)
      $gem_names[x] = nil unless x.nil?
    end unless gd.empty?

  end

  $gem_names.compact!

end # of def do_it

do_it

temp_str    = `rvm current`
gemset_name = temp_str.include?('@') ? temp_str.chomp.split('@').last : 'default'

outfile_path= Pathname.pwd + "install_gemset_#{gemset_name}.s"
OUTFILE     = outfile_path.open('w')

header = <<EOS
###################################################################
###
##  File: #{outfile_path.basename}
##  Desc: Minimum set of gem installs to reinstall entire gemset
##        taking into account the gem dependencies.
##
##        Created #{DateTime.now}
#

rvm gemset use #{gemset_name} #{'default' == gemset_name ? '' : '--create'}

EOS

OUTFILE.puts header

$gem_names.each_slice(10) do |g|
  OUTFILE.puts "gem install #{g.join(' ')}"
end

OUTFILE.close