Module | MCollective::PluginManager |
In: |
lib/mcollective/pluginmanager.rb
|
A simple plugin manager, it stores one plugin each of a specific type the idea is that we can only have one security provider, one connector etc.
Adds a plugin to the list of plugins, we expect a hash like:
{:type => "base", :class => foo.new}
or like:
{:type => "base", :class => "Foo::Bar"}
In the event that we already have a class with the given type an exception will be raised.
If the :class passed is a String then we will delay instantiation till the first time someone asks for the plugin, this is because most likely the registration gets done by inherited() hooks, at which point the plugin class is not final.
If we were to do a .new here the Class initialize method would get called and not the plugins, we there for only initialize the classes when they get requested via []
# File lib/mcollective/pluginmanager.rb, line 25 25: def self.<<(plugin) 26: type = plugin[:type] 27: klass = plugin[:class] 28: 29: raise("Plugin #{type} already loaded") if @plugins.include?(type) 30: 31: 32: # If we get a string then store 'nil' as the instance, signalling that we'll 33: # create the class later on demand. 34: if klass.is_a?(String) 35: @plugins[type] = {:loadtime => Time.now, :class => klass, :instance => nil} 36: Log.instance.debug("Registering plugin #{type} with class #{klass}") 37: else 38: @plugins[type] = {:loadtime => Time.now, :class => klass.class, :instance => klass} 39: Log.instance.debug("Registering plugin #{type} with class #{klass.class}") 40: end 41: end
Gets a plugin by type
# File lib/mcollective/pluginmanager.rb, line 59 59: def self.[](plugin) 60: raise("No plugin #{plugin} defined") unless @plugins.include?(plugin) 61: 62: klass = @plugins[plugin][:class] 63: 64: # Create an instance of the class if one hasn't been done before 65: if @plugins[plugin][:instance] == nil 66: begin 67: @plugins[plugin][:instance] = eval("#{klass}.new") 68: rescue Exception => e 69: raise("Could not create instance of plugin #{plugin}: #{e}") 70: end 71: end 72: 73: Log.instance.debug("Returning plugin #{plugin} with class #{klass}") 74: 75: @plugins[plugin][:instance] 76: end
Removes a plugim the list
# File lib/mcollective/pluginmanager.rb, line 44 44: def self.delete(plugin) 45: @plugins.delete(plugin) if @plugins.include?(plugin) 46: end
Grep‘s over the plugin list and returns the list found
# File lib/mcollective/pluginmanager.rb, line 91 91: def self.grep(regex) 92: @plugins.grep regex 93: end
Finds out if we have a plugin with the given name
# File lib/mcollective/pluginmanager.rb, line 49 49: def self.include?(plugin) 50: @plugins.include?(plugin) 51: end
Loads a class from file by doing some simple search/replace on class names and then doing a require.
# File lib/mcollective/pluginmanager.rb, line 80 80: def self.loadclass(klass) 81: fname = klass.gsub("::", "/").downcase + ".rb" 82: 83: Log.instance.debug("Loading #{klass} from #{fname}") 84: 85: load fname 86: rescue Exception => e 87: Log.instance.error("Failed to load #{klass}: #{e}") 88: end