diff options
| -rw-r--r-- | lib/puppet/application.rb | 16 | ||||
| -rw-r--r-- | lib/puppet/util/command_line.rb | 7 | ||||
| -rw-r--r-- | lib/puppet/util/plugins.rb | 82 |
3 files changed, 100 insertions, 5 deletions
diff --git a/lib/puppet/application.rb b/lib/puppet/application.rb index c3d7355f6..5e69baef4 100644 --- a/lib/puppet/application.rb +++ b/lib/puppet/application.rb @@ -1,4 +1,5 @@ require 'optparse' +require 'puppet/util/plugins' # This class handles all the aspects of a Puppet application/executable # * setting up options @@ -297,11 +298,11 @@ class Application # This is the main application entry point def run - exit_on_fail("initialize") { preinit } - exit_on_fail("parse options") { parse_options } + exit_on_fail("initialize") { hook('preinit') { preinit } } + exit_on_fail("parse options") { hook('parse_options') { parse_options } } exit_on_fail("parse configuration file") { Puppet.settings.parse } if should_parse_config? - exit_on_fail("prepare for execution") { setup } - exit_on_fail("run") { run_command } + exit_on_fail("prepare for execution") { hook('setup') { setup } } + exit_on_fail("run") { hook('run_command') { run_command } } end def main @@ -413,5 +414,12 @@ class Application $stderr.puts "Could not #{message}: #{detail}" exit(code) end + + def hook(step,&block) + Puppet::Plugins.send("before_application_#{step}",:application_object => self) + x = yield + Puppet::Plugins.send("after_application_#{step}",:application_object => self, :return_value => x) + x + end end end diff --git a/lib/puppet/util/command_line.rb b/lib/puppet/util/command_line.rb index 7f74d266a..fb56b2898 100644 --- a/lib/puppet/util/command_line.rb +++ b/lib/puppet/util/command_line.rb @@ -1,3 +1,5 @@ +require "puppet/util/plugins" + module Puppet module Util class CommandLine @@ -23,6 +25,7 @@ module Puppet @stdin = stdin @subcommand_name, @args = subcommand_and_args( @zero, @argv, @stdin ) + Puppet::Plugins.on_commandline_initialization(:command_line_object => self) end attr :subcommand_name @@ -56,7 +59,9 @@ module Puppet puts usage_message elsif available_subcommands.include?(subcommand_name) #subcommand require_application subcommand_name - Puppet::Application.find(subcommand_name).new(self).run + app = Puppet::Application.find(subcommand_name).new(self) + Puppet::Plugins.on_application_initialization(:appliation_object => self) + app.run else abort "Error: Unknown command #{subcommand_name}.\n#{usage_message}" unless execute_external_subcommand end diff --git a/lib/puppet/util/plugins.rb b/lib/puppet/util/plugins.rb new file mode 100644 index 000000000..105fdcd75 --- /dev/null +++ b/lib/puppet/util/plugins.rb @@ -0,0 +1,82 @@ +# +# This system manages an extensible set of metadata about plugins which it +# collects by searching for files named "plugin_init.rb" in a series of +# directories. Initially, these are simply the $LOAD_PATH. +# +# The contents of each file found is executed in the context of a Puppet::Plugins +# object (and thus scoped). An example file might contain: +# +# ------------------------------------------------------- +# @name = "Greet the CA" +# +# @description = %q{ +# This plugin causes a friendly greeting to print out on a master +# that is operating as the CA, after it has been set up but before +# it does anything. +# } +# +# def after_application_setup(options) +# if options[:application_object].is_a?(Puppet::Application::Master) && Puppet::SSL::CertificateAuthority.ca? +# puts "Hey, this is the CA!" +# end +# end +# ------------------------------------------------------- +# +# Note that the instance variables are local to this Puppet::Plugin (and so may be used +# for maintaining state, etc.) but the plugin system does not provide any thread safety +# assurances, so they may not be adequate for some complex use cases. +# +# +module Puppet + class Plugins + Paths = [] # Where we might find plugin initialization code + Loaded = [] # Code we have found (one-to-one with paths once searched) + # + # Return all the Puppet::Plugins we know about, searching any new paths + # + def self.known + Paths[Loaded.length...Paths.length].each { |path| + file = File.join(path,'plugin_init.rb') + Loaded << (File.exist?(file) && new(file)) + } + Loaded.compact + end + # + # Add more places to look for plugins without adding duplicates or changing the + # order of ones we've already found. + # + def self.look_in(*paths) + Paths.replace Paths | paths.flatten.collect { |path| File.expand_path(path) } + end + # + # Initially just look in $LOAD_PATH + # + look_in $LOAD_PATH + # + # Calling methods (hooks) on the class calls the method of the same name on + # all plugins that use that hook, passing in the same arguments to each + # and returning an array containing the results returned by each plugin as + # an array of [plugin_name,result] pairs. + # + def self.method_missing(hook,*args,&block) + known. + select { |p| p.respond_to? hook }. + collect { |p| [p.name,p.send(hook,*args,&block)] } + end + # + # + # + attr_reader :path,:name + def initialize(path) + @name = @path = path + class << self + private + def define_hooks + eval File.read(path),nil,path,1 + end + end + define_hooks + end + end +end + |