Class: MCollective::Client

Inherits:
Object
  • Object
show all
Defined in:
lib/mcollective/client.rb

Overview

Helpers for writing clients that can talk to agents, do discovery and so forth

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(configfile) ⇒ Client

Returns a new instance of Client.



6
7
8
9
10
11
12
13
14
15
16
17
18
 
# File 'lib/mcollective/client.rb', line 6

def initialize(configfile)
  @config = Config.instance
  @config.loadconfig(configfile) unless @config.configured

  @connection = PluginManager["connector_plugin"]
  @security = PluginManager["security_plugin"]

  @security.initiated_by = :client
  @options = nil
  @subscriptions = {}

  @connection.connect
end

Instance Attribute Details

#options ⇒ Object

Returns the value of attribute options.



4
5
6
 
# File 'lib/mcollective/client.rb', line 4

def options
  @options
end

#stats ⇒ Object

Returns the value of attribute stats.



4
5
6
 
# File 'lib/mcollective/client.rb', line 4

def stats
  @stats
end

Instance Method Details

#collective ⇒ Object

Returns the configured main collective if no specific collective is specified as options



22
23
24
25
26
27
28
 
# File 'lib/mcollective/client.rb', line 22

def collective
  if @options[:collective].nil?
    @config.main_collective
  else
    @options[:collective]
  end
end

#disconnect ⇒ Object

Disconnects cleanly from the middleware



31
32
33
34
 
# File 'lib/mcollective/client.rb', line 31

def disconnect
  Log.debug("Disconnecting from the middleware")
  @connection.disconnect
end

#discover(filter, timeout, limit = 0) ⇒ Object

Performs a discovery of nodes matching the filter passed returns an array of nodes

An integer limit can be supplied this will have the effect of the discovery being cancelled soon as it reached the requested limit of hosts



114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
 
# File 'lib/mcollective/client.rb', line 114

def discover(filter, timeout, limit=0)
  raise "Limit has to be an integer" unless limit.is_a?(Fixnum)

  begin
    hosts = []
    Timeout.timeout(timeout) do
      reqid = sendreq("ping", "discovery", filter)
      Log.debug("Waiting #{timeout} seconds for discovery replies to request #{reqid}")

      loop do
        reply = receive(reqid)
        Log.debug("Got discovery reply from #{reply.payload[:senderid]}")
        hosts << reply.payload[:senderid]

        return hosts if limit > 0 && hosts.size == limit
      end
    end
  rescue Timeout::Error => e
  rescue Exception => e
    raise
  ensure
    unsubscribe("discovery", :reply)
  end

  hosts.sort
end

#discovered_req(body, agent, options = false) ⇒ Object

Performs a discovery and then send a request, performs the passed block for each response

times = discovered_req("status", "mcollectived", options, client) {|resp|
   pp resp
}

It returns a hash of times and timeouts for discovery and total run is taken from the options hash which in turn is generally built using MCollective::Optionparser



201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
 
# File 'lib/mcollective/client.rb', line 201

def discovered_req(body, agent, options=false)
  stat = {:starttime => Time.now.to_f, :discoverytime => 0, :blocktime => 0, :totaltime => 0}

  options = @options unless options

  STDOUT.sync = true

  print("Determining the amount of hosts matching filter for #{options[:disctimeout]} seconds .... ")

  begin
    discovered_hosts = discover(options[:filter], options[:disctimeout])
    discovered = discovered_hosts.size
    hosts_responded = []
    hosts_not_responded = discovered_hosts

    stat[:discoverytime] = Time.now.to_f - stat[:starttime]

    puts("#{discovered}\n\n")
  rescue Interrupt
    puts("Discovery interrupted.")
    exit!
  end

  raise("No matching clients found") if discovered == 0

  begin
    Timeout.timeout(options[:timeout]) do
      reqid = sendreq(body, agent, options[:filter])

      (1..discovered).each do |c|
        resp = receive(reqid)

        hosts_responded << resp.payload[:senderid]
        hosts_not_responded.delete(resp.payload[:senderid]) if hosts_not_responded.include?(resp.payload[:senderid])

        yield(resp.payload)
      end
    end
  rescue Interrupt => e
  rescue Timeout::Error => e
  end

  stat[:totaltime] = Time.now.to_f - stat[:starttime]
  stat[:blocktime] = stat[:totaltime] - stat[:discoverytime]
  stat[:responses] = hosts_responded.size
  stat[:responsesfrom] = hosts_responded
  stat[:noresponsefrom] = hosts_not_responded
  stat[:discovered] = discovered

  @stats = stat
  return stat
end

#display_stats(stats, options = false, caption = "stomp call summary") ⇒ Object

Prints out the stats returns from req and discovered_req in a nice way



255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
 
# File 'lib/mcollective/client.rb', line 255

def display_stats(stats, options=false, caption="stomp call summary")
  options = @options unless options

  if options[:verbose]
    puts("\n---- #{caption} ----")

    if stats[:discovered]
      puts("           Nodes: #{stats[:discovered]} / #{stats[:responses]}")
    else
      puts("           Nodes: #{stats[:responses]}")
    end

    printf("      Start Time: %s\n", Time.at(stats[:starttime]))
    printf("  Discovery Time: %.2fms\n", stats[:discoverytime] * 1000)
    printf("      Agent Time: %.2fms\n", stats[:blocktime] * 1000)
    printf("      Total Time: %.2fms\n", stats[:totaltime] * 1000)

  else
    if stats[:discovered]
      printf("\nFinished processing %d / %d hosts in %.2f ms\n\n", stats[:responses], stats[:discovered], stats[:blocktime] * 1000)
    else
      printf("\nFinished processing %d hosts in %.2f ms\n\n", stats[:responses], stats[:blocktime] * 1000)
    end
  end

  if stats[:noresponsefrom].size > 0
    puts("\nNo response from:\n")

    stats[:noresponsefrom].each do |c|
      puts if c % 4 == 1
      printf("%30s", c)
    end

    puts
  end
end

#receive(requestid = nil) ⇒ Object

Blocking call that waits for ever for a message to arrive.

If you give it a requestid this means you’ve previously send a request with that ID and now you just want replies that matches that id, in that case the current connection will just ignore all messages not directed at it and keep waiting for more till it finds a matching message.



84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
 
# File 'lib/mcollective/client.rb', line 84

def receive(requestid = nil)
  reply = nil

  begin
    reply = @connection.receive
    reply.type = :reply
    reply.expected_msgid = requestid

    reply.decode!

    reply.payload[:senderid] = Digest::MD5.hexdigest(reply.payload[:senderid]) if ENV.include?("MCOLLECTIVE_ANON")

    raise(MsgDoesNotMatchRequestID, "Message reqid #{requestid} does not match our reqid #{reply.requestid}") unless reply.requestid == requestid
  rescue SecurityValidationFailed => e
    Log.warn("Ignoring a message that did not pass security validations")
    retry
  rescue MsgDoesNotMatchRequestID => e
    Log.debug("Ignoring a message for some other client")
    retry
  end

  reply
end

#req(body, agent = nil, options = false, waitfor = 0) ⇒ Object

Send a request, performs the passed block for each response

times = req(“status”, “mcollectived”, options, client) {|resp|

pp resp

}

It returns a hash of times and timeouts for discovery and total run is taken from the options hash which in turn is generally built using MCollective::Optionparser



149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
 
# File 'lib/mcollective/client.rb', line 149

def req(body, agent=nil, options=false, waitfor=0)
  if body.is_a?(Message)
    agent = body.agent
    options = body.options
    waitfor = body.discovered_hosts.size || 0
  end

  stat = {:starttime => Time.now.to_f, :discoverytime => 0, :blocktime => 0, :totaltime => 0}

  options = @options unless options

  STDOUT.sync = true

  hosts_responded = 0

  begin
    Timeout.timeout(options[:timeout]) do
      reqid = sendreq(body, agent, options[:filter])

      loop do
        resp = receive(reqid)

        hosts_responded += 1

        yield(resp.payload)

        break if (waitfor != 0 && hosts_responded >= waitfor)
      end
    end
  rescue Interrupt => e
  rescue Timeout::Error => e
  ensure
    unsubscribe(agent, :reply)
  end

  stat[:totaltime] = Time.now.to_f - stat[:starttime]
  stat[:blocktime] = stat[:totaltime] - stat[:discoverytime]
  stat[:responses] = hosts_responded
  stat[:noresponsefrom] = []

  @stats = stat
  return stat
end

#sendreq(msg, agent, filter = {}) ⇒ Object

Sends a request and returns the generated request id, doesn’t wait for responses and doesn’t execute any passed in code blocks for responses



38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
 
# File 'lib/mcollective/client.rb', line 38

def sendreq(msg, agent, filter = {})
  if msg.is_a?(Message)
    request = msg
    agent = request.agent
  else
    ttl = @options[:ttl] || @config.ttl
    request = Message.new(msg, nil, {:agent => agent, :type => :request, :collective => collective, :filter => filter, :ttl => ttl})
    request.reply_to = @options[:reply_to] if @options[:reply_to]
  end

  request.encode!

  Log.debug("Sending request #{request.requestid} to the #{request.agent} agent with ttl #{request.ttl} in collective #{request.collective}")

  subscribe(agent, :reply)

  request.publish

  request.requestid
end

#subscribe(agent, type) ⇒ Object 



59
60
61
62
63
64
65
66
67
 
# File 'lib/mcollective/client.rb', line 59

def subscribe(agent, type)
  unless @subscriptions.include?(agent)
    subscription = Util.make_subscriptions(agent, type, collective)
    Log.debug("Subscribing to #{type} target for agent #{agent}")

    Util.subscribe(subscription)
    @subscriptions[agent] = 1
  end
end

#unsubscribe(agent, type) ⇒ Object 



69
70
71
72
73
74
75
76
77
 
# File 'lib/mcollective/client.rb', line 69

def unsubscribe(agent, type)
  if @subscriptions.include?(agent)
    subscription = Util.make_subscriptions(agent, type, collective)
    Log.debug("Unsubscribing #{type} target for #{agent}")

    Util.unsubscribe(subscription)
    @subscriptions.delete(agent)
  end
end