Class MCollective::RPC::Agent
In: lib/mcollective/rpc/agent.rb
Parent: Object

A wrapper around the traditional agent, it takes care of a lot of the tedious setup you would do for each agent allowing you to just create methods following a naming standard leaving the heavy lifting up to this clas.

See marionette-collective.org/simplerpc/agents.html

It only really makes sense to use this with a Simple RPC client on the other end, basic usage would be:

   module MCollective
      module Agent
         class Helloworld<RPC::Agent
            matadata :name        => "Test SimpleRPC Agent",
                     :description => "A simple test",
                     :author      => "You",
                     :license     => "1.1",
                     :url         => "http://your.com/,
                     :timeout     => 60

            action "hello" do
                reply[:msg] = "Hello #{request[:name]}"
            end

            action "foo" do
                implemented_by "/some/script.sh"
            end
         end
      end
   end

If you wish to implement the logic for an action using an external script use the implemented_by method that will cause your script to be run with 2 arguments.

The first argument is a file containing JSON with the request and the 2nd argument is where the script should save its output as a JSON hash.

We also currently have the validation code in here, this will be moved to plugins soon.

Methods

actions   handlemsg   help   help   new  

Attributes

config  [R] 
ddl  [R] 
logger  [R] 
meta  [RW] 
reply  [RW] 
request  [RW] 
timeout  [R] 

Public Class methods

Returns an array of actions this agent support

[Source]

     # File lib/mcollective/rpc/agent.rb, line 143
143:             def self.actions
144:                 public_instance_methods.sort.grep(/_action$/).map do |method|
145:                     $1 if method =~ /(.+)_action$/
146:                 end
147:             end

Generates help using the template based on the data created with metadata and input

[Source]

     # File lib/mcollective/rpc/agent.rb, line 129
129:             def self.help(template)
130:                 if @ddl
131:                     @ddl.help(template)
132:                 else
133:                     "No DDL defined"
134:                 end
135:             end

[Source]

    # File lib/mcollective/rpc/agent.rb, line 44
44:             def initialize
45:                 # Default meta data unset
46:                 @meta = {:timeout     => 10,
47:                          :name        => "Unknown",
48:                          :description => "Unknown",
49:                          :author      => "Unknown",
50:                          :license     => "Unknown",
51:                          :version     => "Unknown",
52:                          :url         => "Unknown"}
53: 
54:                 @timeout = meta[:timeout] || 10
55:                 @logger = Log.instance
56:                 @config = Config.instance
57:                 @agent_name = self.class.to_s.split("::").last.downcase
58: 
59:                 # Loads the DDL so we can later use it for validation
60:                 # and help generation
61:                 begin
62:                     @ddl = DDL.new(@agent_name)
63:                 rescue
64:                     @ddl = nil
65:                 end
66: 
67:                 # if we have a global authorization provider enable it
68:                 # plugins can still override it per plugin
69:                 self.class.authorized_by(@config.rpcauthprovider) if @config.rpcauthorization
70: 
71:                 startup_hook
72:             end

Public Instance methods

[Source]

     # File lib/mcollective/rpc/agent.rb, line 74
 74:             def handlemsg(msg, connection)
 75:                 @request = RPC.request(msg)
 76:                 @reply = RPC.reply
 77: 
 78:                 begin
 79:                     # Calls the authorization plugin if any is defined
 80:                     # if this raises an exception we wil just skip processing this
 81:                     # message
 82:                     authorization_hook(@request) if respond_to?("authorization_hook")
 83: 
 84: 
 85:                     # Audits the request, currently continues processing the message
 86:                     # we should make this a configurable so that an audit failure means
 87:                     # a message wont be processed by this node depending on config
 88:                     audit_request(@request, connection)
 89: 
 90:                     before_processing_hook(msg, connection)
 91: 
 92:                     if respond_to?("#{@request.action}_action")
 93:                         send("#{@request.action}_action")
 94:                     else
 95:                         raise UnknownRPCAction, "Unknown action: #{@request.action}"
 96:                     end
 97:                 rescue RPCAborted => e
 98:                     @reply.fail e.to_s, 1
 99: 
100:                 rescue UnknownRPCAction => e
101:                     @reply.fail e.to_s, 2
102: 
103:                 rescue MissingRPCData => e
104:                     @reply.fail e.to_s, 3
105: 
106:                 rescue InvalidRPCData => e
107:                     @reply.fail e.to_s, 4
108: 
109:                 rescue UnknownRPCError => e
110:                     @reply.fail e.to_s, 5
111: 
112:                 rescue Exception => e
113:                     @reply.fail e.to_s, 5
114: 
115:                 end
116: 
117:                 after_processing_hook
118: 
119:                 if @request.should_respond?
120:                     return @reply.to_hash
121:                 else
122:                     Log.debug("Client did not request a response, surpressing reply")
123:                     return nil
124:                 end
125:             end

to auto generate help

[Source]

     # File lib/mcollective/rpc/agent.rb, line 138
138:             def help
139:                 self.help("#{@config[:configdir]}/rpc-help.erb")
140:             end

[Validate]