helpers.rb

#
# Author:: John Dewey (<john@dewey.ws>)
# Cookbook:: chef-client
# Library:: helpers
#
# Copyright:: 2012-2017, John Dewey
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

module Opscode
  module ChefClient
    # helper methods for use in chef-client recipe code
    module Helpers
      include Chef::Mixin::Which
      require 'digest/md5'

      def wmi_property_from_query(wmi_property, wmi_query)
        @wmi = ::WIN32OLE.connect('winmgmts://')
        result = @wmi.ExecQuery(wmi_query)
        return unless result.each.count > 0
        result.each.next.send(wmi_property)
      end

      # Generate a uniformly distributed unique number to sleep.
      def splay_sleep_time(splay)
        seed = node['shard_seed'] || Digest::MD5.hexdigest(node.name).to_s.hex
        random = Random.new(seed.to_i)
        random.rand(splay)
      end

      def root_owner
        if platform?('windows')
          wmi_property_from_query(:name, "select * from Win32_UserAccount where sid like 'S-1-5-21-%-500' and LocalAccount=True")
        else
          'root'
        end
      end

      def create_chef_directories
        # root_owner is not in scope in the block below.
        d_owner = root_owner
        %w(run_path file_cache_path file_backup_path log_dir conf_dir).each do |dir|
          next if node['chef_client'][dir].nil?
          # Do not redefine the resource if it exist
          find_resource(:directory, node['chef_client'][dir]) do
            recursive true
            mode '0755' if dir == 'log_dir'
            owner d_owner
            group node['root_group']
          end
        end
      end

      def find_chef_client
        # executable on windows really means it ends in .exec/.bat
        existence_check = platform?('windows') ? :exist? : :executable?

        if ::File.send(existence_check, node['chef_client']['bin'])
          Chef::Log.debug 'Using chef-client bin from node attributes'
          node['chef_client']['bin']
        else
          Chef::Log.debug "Searching path for chef-client bin as node['chef_client']['bin'] does not exist"
          which('chef-client') || raise("Could not locate the chef-client bin in any known path. Please set the proper path by overriding the node['chef_client']['bin'] attribute.")
        end
      end

      # Return true/false if node['chef_client']['cron']['environment_variables']
      # is defined.
      def env_vars?
        !!node['chef_client']['cron']['environment_variables']
      end

      # Return node['chef_client']['cron']['environment_variables']
      def env_vars
        node['chef_client']['cron']['environment_variables']
      end

      # Return true/false if node['chef_client']['cron']['priority'] is defined.
      def prioritized?
        !!node['chef_client']['cron']['priority']
      end

      # Determine the process priority for chef-client.
      # Guard against unwanted values, returning nil.
      # Returns the desired priority to use with /bin/nice.
      def process_priority
        return unless prioritized?
        if platform?('windows')
          Chef::Log.warn 'Cannot prioritize the chef-client process on Windows hosts.'
          return
        end

        priority = node['chef_client']['cron']['priority']
        # Convert strings to integers. If we see anything that doesn't match an
        # integer, bail.
        if priority.is_a?(String)
          unless /^-?\d+$/ =~ priority
            Chef::Log.warn "Process priority (#{priority}) is invalid. It must be an integer in the range -20 to 19, inclusize."
            return
          end
          priority = priority.to_i
        end

        if priority < -20 || priority > 19
          Chef::Log.warn "Process priority (#{priority}) is invalid. It must be an integer in the range -20 to 19, inclusize."
          return
        end
        priority
      end
    end
  end
end

Chef::DSL::Recipe.include Opscode::ChefClient::Helpers
Chef::Resource.include Opscode::ChefClient::Helpers