| Class | MCollective::Agents |
| In: |
lib/mcollective/agents.rb
|
| Parent: | Object |
A collection of agents, loads them, reloads them and dispatches messages to them. It uses the PluginManager to store, load and manage instances of plugins.
Get a list of agents that we have
# File lib/mcollective/agents.rb, line 145
145: def self.agentlist
146: @@agents.keys
147: end
# File lib/mcollective/agents.rb, line 5
5: def initialize(agents = {})
6: @config = Config.instance
7: raise ("Configuration has not been loaded, can't load agents") unless @config.configured
8:
9: @@agents = agents
10:
11: loadagents
12: end
Checks if a plugin should be activated by calling activate? on it if it responds to that method else always activate it
# File lib/mcollective/agents.rb, line 85
85: def activate_agent?(agent)
86: klass = Kernel.const_get("MCollective").const_get("Agent").const_get(agent.capitalize)
87:
88: if klass.respond_to?("activate?")
89: return klass.activate?
90: else
91: Log.debug("#{klass} does not have an activate? method, activating as default")
92: return true
93: end
94: rescue Exception => e
95: Log.warn("Agent activation check for #{agent} failed: #{e.class}: #{e}")
96: return false
97: end
Deletes all agents
# File lib/mcollective/agents.rb, line 15
15: def clear!
16: @@agents.each_key do |agent|
17: PluginManager.delete "#{agent}_agent"
18: Util.unsubscribe(Util.make_subscriptions(agent, :broadcast))
19: end
20:
21: @@agents = {}
22: end
Dispatches a message to an agent, accepts a block that will get run if there are any replies to process from the agent
# File lib/mcollective/agents.rb, line 118
118: def dispatch(request, connection)
119: Log.debug("Dispatching a message to agent #{request.agent}")
120:
121: Thread.new do
122: begin
123: agent = PluginManager["#{request.agent}_agent"]
124:
125: Timeout::timeout(agent.timeout) do
126: replies = agent.handlemsg(request.payload, connection)
127:
128: # Agents can decide if they wish to reply or not,
129: # returning nil will mean nothing goes back to the
130: # requestor
131: unless replies == nil
132: yield(replies)
133: end
134: end
135: rescue Timeout::Error => e
136: Log.warn("Timeout while handling message for #{request.agent}")
137: rescue Exception => e
138: Log.error("Execution of #{request.agent} failed: #{e}")
139: Log.error(e.backtrace.join("\n\t\t"))
140: end
141: end
142: end
searches the libdirs for agents
# File lib/mcollective/agents.rb, line 100
100: def findagentfile(agentname)
101: @config.libdir.each do |libdir|
102: agentfile = File.join([libdir, "mcollective", "agent", "#{agentname}.rb"])
103: if File.exist?(agentfile)
104: Log.debug("Found #{agentname} at #{agentfile}")
105: return agentfile
106: end
107: end
108: return false
109: end
Determines if we have an agent with a certain name
# File lib/mcollective/agents.rb, line 112
112: def include?(agentname)
113: PluginManager.include?("#{agentname}_agent")
114: end
Loads a specified agent from disk if available
# File lib/mcollective/agents.rb, line 42
42: def loadagent(agentname)
43: agentfile = findagentfile(agentname)
44: return false unless agentfile
45: classname = class_for_agent(agentname)
46:
47: PluginManager.delete("#{agentname}_agent")
48:
49: begin
50: single_instance = ["registration", "discovery"].include?(agentname)
51:
52: PluginManager.loadclass(classname)
53:
54: if activate_agent?(agentname)
55: PluginManager << {:type => "#{agentname}_agent", :class => classname, :single_instance => single_instance}
56:
57: # Attempt to instantiate the agent once so any validation and hooks get run
58: # this does a basic sanity check on the agent as a whole, if this fails it
59: # will be removed from the plugin list
60: PluginManager["#{agentname}_agent"]
61:
62: Util.subscribe(Util.make_subscriptions(agentname, :broadcast)) unless @@agents.include?(agentname)
63:
64: @@agents[agentname] = {:file => agentfile}
65: return true
66: else
67: Log.debug("Not activating agent #{agentname} due to agent policy in activate? method")
68: return false
69: end
70: rescue Exception => e
71: Log.error("Loading agent #{agentname} failed: #{e}")
72: PluginManager.delete("#{agentname}_agent")
73: return false
74: end
75: end
Loads all agents from disk
# File lib/mcollective/agents.rb, line 25
25: def loadagents
26: Log.debug("Reloading all agents from disk")
27:
28: clear!
29:
30: @config.libdir.each do |libdir|
31: agentdir = "#{libdir}/mcollective/agent"
32: next unless File.directory?(agentdir)
33:
34: Dir.new(agentdir).grep(/\.rb$/).each do |agent|
35: agentname = File.basename(agent, ".rb")
36: loadagent(agentname) unless PluginManager.include?("#{agentname}_agent")
37: end
38: end
39: end