Class MCollective::Message
In: lib/mcollective/message.rb
Parent: Object

container for a message, its headers, agent, collective and other meta data

Methods

Constants

VALIDTYPES = [:message, :request, :direct_request, :reply]

Attributes

agent  [RW] 
collective  [RW] 
discovered_hosts  [RW] 
expected_msgid  [R] 
filter  [RW] 
headers  [RW] 
message  [R] 
msgtime  [R] 
options  [RW] 
payload  [R] 
reply_to  [R] 
request  [R] 
requestid  [RW] 
ttl  [RW] 
type  [R] 
validated  [R] 

Public Class methods

payload - the message body without headers etc, just the text message - the original message received from the middleware options[:base64] - if the body base64 encoded? options[:agent] - the agent the message is for/from options[:collective] - the collective its for/from options[:headers] - the message headers options[:type] - an indicator about the type of message, :message, :request, :direct_request or :reply options[:request] - if this is a reply this should old the message we are replying to options[:filter] - for requests, the filter to encode into the message options[:options] - the normal client options hash options[:ttl] - the maximum amount of seconds this message can be valid for options[:expected_msgid] - in the case of replies this is the msgid it is expecting in the replies

[Source]

    # File lib/mcollective/message.rb, line 22
22:     def initialize(payload, message, options = {})
23:       options = {:base64 => false,
24:                  :agent => nil,
25:                  :headers => {},
26:                  :type => :message,
27:                  :request => nil,
28:                  :filter => Util.empty_filter,
29:                  :options => {},
30:                  :ttl => 60,
31:                  :expected_msgid => nil,
32:                  :collective => nil}.merge(options)
33: 
34:       @payload = payload
35:       @message = message
36:       @requestid = nil
37:       @discovered_hosts = nil
38:       @reply_to = nil
39: 
40:       @type = options[:type]
41:       @headers = options[:headers]
42:       @base64 = options[:base64]
43:       @filter = options[:filter]
44:       @expected_msgid = options[:expected_msgid]
45:       @options = options[:options]
46: 
47:       @ttl = @options[:ttl] || Config.instance.ttl
48:       @msgtime = 0
49: 
50:       @validated = false
51: 
52:       if options[:request]
53:         @request = options[:request]
54:         @agent = request.agent
55:         @collective = request.collective
56:         @type = :reply
57:       else
58:         @agent = options[:agent]
59:         @collective = options[:collective]
60:       end
61: 
62:       base64_decode!
63:     end

Public Instance methods

[Source]

     # File lib/mcollective/message.rb, line 127
127:     def base64?
128:       @base64
129:     end

[Source]

     # File lib/mcollective/message.rb, line 113
113:     def base64_decode!
114:       return unless @base64
115: 
116:       @payload = SSL.base64_decode(@payload)
117:       @base64 = false
118:     end

[Source]

     # File lib/mcollective/message.rb, line 120
120:     def base64_encode!
121:       return if @base64
122: 
123:       @payload = SSL.base64_encode(@payload)
124:       @base64 = true
125:     end

[Source]

     # File lib/mcollective/message.rb, line 233
233:     def create_reqid
234:       Digest::MD5.hexdigest("#{Config.instance.identity}-#{Time.now.to_f}-#{agent}-#{collective}")
235:     end

[Source]

     # File lib/mcollective/message.rb, line 177
177:     def decode!
178:       raise "Cannot decode message type #{type}" unless [:request, :reply].include?(type)
179: 
180:       @payload = PluginManager["security_plugin"].decodemsg(self)
181: 
182:       if type == :request
183:         raise 'callerid in request is not valid, surpressing reply to potentially forged request' unless PluginManager["security_plugin"].valid_callerid?(payload[:callerid])
184:       end
185: 
186:       [:collective, :agent, :filter, :requestid, :ttl, :msgtime].each do |prop|
187:         instance_variable_set("@#{prop}", payload[prop]) if payload.include?(prop)
188:       end
189:     end

[Source]

     # File lib/mcollective/message.rb, line 131
131:     def encode!
132:       case type
133:         when :reply
134:           raise "Cannot encode a reply message if no request has been associated with it" unless request
135:           raise 'callerid in original request is not valid, surpressing reply to potentially forged request' unless PluginManager["security_plugin"].valid_callerid?(request.payload[:callerid])
136: 
137:           @requestid = request.payload[:requestid]
138:           @payload = PluginManager["security_plugin"].encodereply(agent, payload, requestid, request.payload[:callerid])
139:         when :request, :direct_request
140:           validate_compount_filter(@filter["compound"]) unless @filter["compound"].empty?
141: 
142:           @requestid = create_reqid
143:           @payload = PluginManager["security_plugin"].encoderequest(Config.instance.identity, payload, requestid, filter, agent, collective, ttl)
144:         else
145:           raise "Cannot encode #{type} messages"
146:       end
147:     end

in the case of reply messages we are expecting replies to a previously created message. This stores a hint to that previously sent message id and can be used by other classes like the security plugins as a means of optimizing their behavior like by ignoring messages not directed at us.

[Source]

     # File lib/mcollective/message.rb, line 108
108:     def expected_msgid=(msgid)
109:       raise "Can only store the expected msgid for reply messages" unless @type == :reply
110:       @expected_msgid = msgid
111:     end

publish a reply message by creating a target name and sending it

[Source]

     # File lib/mcollective/message.rb, line 215
215:     def publish
216:       Timeout.timeout(2) do
217:         # If we've been specificaly told about hosts that were discovered
218:         # use that information to do P2P calls if appropriate else just
219:         # send it as is.
220:         if @discovered_hosts && Config.instance.direct_addressing
221:           if @discovered_hosts.size <= Config.instance.direct_addressing_threshold
222:             self.type = :direct_request
223:             Log.debug("Handling #{requestid} as a direct request")
224:           end
225: 
226:           PluginManager["connector_plugin"].publish(self)
227:         else
228:           PluginManager["connector_plugin"].publish(self)
229:         end
230:       end
231:     end

Sets a custom reply-to target for requests. The connector plugin should inspect this when constructing requests and set this header ensuring replies will go to the custom target otherwise the connector should just do what it usually does

[Source]

     # File lib/mcollective/message.rb, line 97
 97:     def reply_to=(target)
 98:       raise "Custom reply targets can only be set on requests" unless [:request, :direct_request].include?(@type)
 99: 
100:       @reply_to = target
101:     end

Sets the message type to one of the known types. In the case of :direct_request the list of hosts to communicate with should have been set with discovered_hosts else an exception will be raised. This is for extra security, we never accidentally want to send a direct request without a list of hosts or something weird like that as it might result in a filterless broadcast being sent.

Additionally you simply cannot set :direct_request if direct_addressing was not enabled this is to force a workflow that doesnt not yield in a mistake when someone might assume direct_addressing is enabled when its not.

[Source]

    # File lib/mcollective/message.rb, line 74
74:     def type=(type)
75:       raise "Unknown message type #{type}" unless VALIDTYPES.include?(type)
76: 
77:       if type == :direct_request
78:         raise "Direct requests is not enabled using the direct_addressing config option" unless Config.instance.direct_addressing
79: 
80:         unless @discovered_hosts && !@discovered_hosts.empty?
81:           raise "Can only set type to :direct_request if discovered_hosts have been set"
82:         end
83: 
84:         # clear out the filter, custom discovery sources might interpret the filters
85:         # different than the remote mcollectived and in directed mode really the only
86:         # filter that matters is the agent filter
87:         @filter = Util.empty_filter
88:         @filter["agent"] << @agent
89:       end
90: 
91:       @type = type
92:     end

Perform validation against the message by checking filters and ttl

[Source]

     # File lib/mcollective/message.rb, line 192
192:     def validate
193:       raise "Can only validate request messages" unless type == :request
194: 
195:       msg_age = Time.now.utc.to_i - msgtime
196: 
197:       if msg_age > ttl
198:         cid = ""
199:         cid += payload[:callerid] + "@" if payload.include?(:callerid)
200:         cid += payload[:senderid]
201: 
202:         if msg_age > ttl
203:           PluginManager["global_stats"].ttlexpired
204: 
205:           raise(MsgTTLExpired, "Message #{requestid} from #{cid} created at #{msgtime} is #{msg_age} seconds old, TTL is #{ttl}")
206:         end
207:       end
208: 
209:       raise(NotTargettedAtUs, "Received message is not targetted to us") unless PluginManager["security_plugin"].validate_filter?(payload[:filter])
210: 
211:       @validated = true
212:     end

[Source]

     # File lib/mcollective/message.rb, line 149
149:     def validate_compount_filter(compound_filter)
150:       compound_filter.each do |filter|
151:         filter.each do |statement|
152:           if statement["fstatement"]
153:             functionname = statement["fstatement"]["name"]
154:             pluginname = Data.pluginname(functionname)
155:             value = statement["fstatement"]["value"]
156: 
157:             begin
158:               ddl = DDL.new(pluginname, :data)
159:             rescue
160:               raise DDLValidationError, "Could not find DDL for data plugin #{pluginname}, cannot use #{functionname}() in discovery"
161:             end
162: 
163:             # parses numbers and booleans entered as strings into proper
164:             # types of data so that DDL validation will pass
165:             statement["fstatement"]["params"] = Data.ddl_transform_input(ddl, statement["fstatement"]["params"])
166: 
167:             Data.ddl_validate(ddl, statement["fstatement"]["params"])
168: 
169:             unless value && Data.ddl_has_output?(ddl, value)
170:               raise DDLValidationError, "#{functionname}() does not return a #{value} value"
171:             end
172:           end
173:         end
174:       end
175:     end

[Validate]