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

Constant Summary collapse

@@request_sequence = 
0

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ Client

Returns a new instance of Client.



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

def initialize(options)
  @config = Config.instance
  @options = nil

  if options.is_a?(String)
    # String is the path to a config file
    @config.loadconfig(options) unless @config.configured
  elsif options.is_a?(Hash)
    @config.loadconfig(options[:config]) unless @config.configured
    @options = options
    @connection_timeout = options[:connection_timeout]
  else
    raise "Invalid parameter passed to Client constructor. Valid types are Hash or String"
  end

  @connection_timeout ||= @config.connection_timeout

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

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

  @discoverer = Discovery.new(self)

  # Time box the connection if a timeout has been specified
  # connection_timeout defaults to nil which means it will try forever if
  # not specified
  begin
    Timeout::timeout(@connection_timeout, ClientTimeoutError) do
      @connection.connect
    end
  rescue ClientTimeoutError => e
    Log.error("Timeout occured while trying to connect to middleware")
    raise e
  end
end

Instance Attribute Details

#connection_timeout ⇒ Object

Returns the value of attribute connection_timeout.



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

def connection_timeout
  @connection_timeout
end

#discoverer ⇒ Object

Returns the value of attribute discoverer.



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

def discoverer
  @discoverer
end

#options ⇒ Object

Returns the value of attribute options.



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

def options
  @options
end

#stats ⇒ Object

Returns the value of attribute stats.



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

def stats
  @stats
end

Class Method Details

.request_sequence ⇒ Object 



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# File 'lib/mcollective/client.rb', line 45

def self.request_sequence
  @@request_sequence
end

Instance Method Details

#collective ⇒ Object

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



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# File 'lib/mcollective/client.rb', line 51

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

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



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# File 'lib/mcollective/client.rb', line 76

def createreq(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_sequence += 1

  request.encode!
  subscribe(agent, :reply) unless request.reply_to
  request
end

#disconnect ⇒ Object

Disconnects cleanly from the middleware



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# File 'lib/mcollective/client.rb', line 60

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



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# File 'lib/mcollective/client.rb', line 150

def discover(filter, timeout, limit=0)
  @discoverer.discover(filter.merge({'collective' => collective}), timeout, limit)
end

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



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# File 'lib/mcollective/client.rb', line 268

def discovered_req(body, agent, options=false)
  raise "Client#discovered_req has been removed, please port your agent and client to the SimpleRPC framework"
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



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# File 'lib/mcollective/client.rb', line 273

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.



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# File 'lib/mcollective/client.rb', line 118

def receive(requestid = nil)
  reply = nil

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

    reply.decode!

    unless reply.requestid == requestid
      raise(MsgDoesNotMatchRequestID, "Message reqid #{reply.requestid} does not match our reqid #{requestid}")
    end

    Log.debug("Received reply to #{reply.requestid} from #{reply.payload[:senderid]}")
  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 : #{e.message}")
    retry
  end

  reply
end

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



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# File 'lib/mcollective/client.rb', line 162

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

  @options = options if options
  threaded = @options[:threaded]
  timeout = @discoverer.discovery_timeout(@options[:timeout], @options[:filter])
  request = createreq(body, agent, @options[:filter])
  publish_timeout = @options[:publish_timeout]
  stat = {:starttime => Time.now.to_f, :discoverytime => 0, :blocktime => 0, :totaltime => 0}
  STDOUT.sync = true
  hosts_responded = 0


  begin
    if threaded
      hosts_responded = threaded_req(request, publish_timeout, timeout, waitfor, &block)
    else
      hosts_responded = unthreaded_req(request, publish_timeout, timeout, waitfor, &block)
    end
  rescue Interrupt => e
  ensure
    unsubscribe(agent, :reply)
  end

  return update_stat(stat, hosts_responded, request.requestid)
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



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# File 'lib/mcollective/client.rb', line 67

def sendreq(msg, agent, filter = {})
  request = createreq(msg, agent, filter)

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

  request.publish
  request.requestid
end

#start_publisher(request, publish_timeout) ⇒ Object

Starts the request publishing routine



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# File 'lib/mcollective/client.rb', line 224

def start_publisher(request, publish_timeout)
  Log.debug("Starting publishing with publish timeout of #{publish_timeout}")
  begin
    Timeout.timeout(publish_timeout) do
      Log.debug("Sending request #{request.requestid} to the #{request.agent} agent with ttl #{request.ttl} in collective #{request.collective}")
      request.publish
    end
  rescue Timeout::Error => e
    Log.warn("Could not publish all messages. Publishing timed out.")
  end
end

#start_receiver(requestid, waitfor, timeout, &block) ⇒ Object

Starts the response receiver routine Expected to return the amount of received responses.



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# File 'lib/mcollective/client.rb', line 238

def start_receiver(requestid, waitfor, timeout, &block)
  Log.debug("Starting response receiver with timeout of #{timeout}")
  hosts_responded = 0
  begin
    Timeout.timeout(timeout) do
      begin
        resp = receive(requestid)
        yield resp.payload
        hosts_responded += 1
      end while (waitfor == 0 || hosts_responded < waitfor)
    end
  rescue Timeout::Error => e
    if (waitfor > hosts_responded)
      Log.warn("Could not receive all responses. Expected : #{waitfor}. Received : #{hosts_responded}")
    end
  end

  hosts_responded
end

#subscribe(agent, type) ⇒ Object 



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# File 'lib/mcollective/client.rb', line 93

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

#threaded_req(request, publish_timeout, timeout, waitfor, &block) ⇒ Object

Starts the client receiver and publisher in threads. This is activated when the ‘threader_client’ configuration option is set.



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# File 'lib/mcollective/client.rb', line 203

def threaded_req(request, publish_timeout, timeout, waitfor, &block)
  Log.debug("Starting threaded client")
  publisher = Thread.new do
    start_publisher(request, publish_timeout)
  end

  # When the client is threaded we add the publishing timeout to
  # the agent timeout so that the receiver doesn't time out before
  # publishing has finished in cases where publish_timeout >= timeout.
  total_timeout = publish_timeout + timeout
  hosts_responded = 0

  receiver = Thread.new do
    hosts_responded = start_receiver(request.requestid, waitfor, total_timeout, &block)
  end

  receiver.join
  hosts_responded
end

#unsubscribe(agent, type) ⇒ Object 



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# File 'lib/mcollective/client.rb', line 103

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

#unthreaded_req(request, publish_timeout, timeout, waitfor, &block) ⇒ Object

Starts the client receiver and publisher unthreaded. This is the default client behaviour.



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# File 'lib/mcollective/client.rb', line 195

def unthreaded_req(request, publish_timeout, timeout, waitfor, &block)
  start_publisher(request, publish_timeout)
  start_receiver(request.requestid, waitfor, timeout, &block)
end

#update_stat(stat, hosts_responded, requestid) ⇒ Object 



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# File 'lib/mcollective/client.rb', line 258

def update_stat(stat, hosts_responded, requestid)
  stat[:totaltime] = Time.now.to_f - stat[:starttime]
  stat[:blocktime] = stat[:totaltime] - stat[:discoverytime]
  stat[:responses] = hosts_responded
  stat[:noresponsefrom] = []
  stat[:requestid] = requestid

  @stats = stat
end