Class MCollective::RPC::Client
In: lib/mcollective/rpc/client.rb
Parent: Object

The main component of the Simple RPC client system, this wraps around MCollective::Client and just brings in a lot of convention and standard approached.

Methods

Attributes

agent  [R] 
batch_mode  [R] 
batch_size  [R] 
batch_sleep_time  [R] 
client  [R] 
config  [RW] 
ddl  [R] 
discovery_method  [R] 
discovery_options  [R] 
filter  [RW] 
limit_method  [R] 
limit_seed  [R] 
limit_targets  [R] 
output_format  [R] 
progress  [RW] 
reply_to  [RW] 
stats  [R] 
timeout  [RW] 
ttl  [RW] 
verbose  [RW] 

Public Class methods

Creates a stub for a remote agent, you can pass in an options array in the flags which will then be used else it will just create a default options array with filtering enabled based on the standard command line use.

  rpc = RPC::Client.new("rpctest", :configfile => "client.cfg", :options => options)

You typically would not call this directly you‘d use MCollective::RPC#rpcclient instead which is a wrapper around this that can be used as a Mixin

[Source]

     # File lib/mcollective/rpc/client.rb, line 20
 20:       def initialize(agent, flags = {})
 21:         if flags.include?(:options)
 22:           initial_options = flags[:options]
 23: 
 24:         elsif @@initial_options
 25:           initial_options = Marshal.load(@@initial_options)
 26: 
 27:         else
 28:           oparser = MCollective::Optionparser.new({:verbose => false, :progress_bar => true, :mcollective_limit_targets => false, :batch_size => nil, :batch_sleep_time => 1}, "filter")
 29: 
 30:           initial_options = oparser.parse do |parser, opts|
 31:             if block_given?
 32:               yield(parser, opts)
 33:             end
 34: 
 35:             Helpers.add_simplerpc_options(parser, opts)
 36:           end
 37: 
 38:           @@initial_options = Marshal.dump(initial_options)
 39:         end
 40: 
 41:         @initial_options = initial_options
 42:         @stats = Stats.new
 43:         @agent = agent
 44:         @timeout = initial_options[:timeout] || 5
 45:         @verbose = initial_options[:verbose]
 46:         @filter = initial_options[:filter] || Util.empty_filter
 47:         @config = initial_options[:config]
 48:         @discovered_agents = nil
 49:         @progress = initial_options[:progress_bar]
 50:         @limit_targets = initial_options[:mcollective_limit_targets]
 51:         @limit_method = Config.instance.rpclimitmethod
 52:         @limit_seed = initial_options[:limit_seed] || nil
 53:         @output_format = initial_options[:output_format] || :console
 54:         @force_direct_request = false
 55:         @reply_to = initial_options[:reply_to]
 56:         @discovery_method = initial_options[:discovery_method] || Config.instance.default_discovery_method
 57:         @discovery_options = initial_options[:discovery_options] || []
 58:         @force_display_mode = initial_options[:force_display_mode] || false
 59: 
 60:         @batch_size = Integer(initial_options[:batch_size] || 0)
 61:         @batch_sleep_time = Float(initial_options[:batch_sleep_time] || 1)
 62:         @batch_mode = @batch_size > 0
 63: 
 64:         agent_filter agent
 65: 
 66:         @client = MCollective::Client.new(@config)
 67:         @client.options = initial_options
 68: 
 69:         @discovery_timeout = discovery_timeout
 70: 
 71:         @collective = @client.collective
 72:         @ttl = initial_options[:ttl] || Config.instance.ttl
 73: 
 74:         # if we can find a DDL for the service override
 75:         # the timeout of the client so we always magically
 76:         # wait appropriate amounts of time.
 77:         #
 78:         # We add the discovery timeout to the ddl supplied
 79:         # timeout as the discovery timeout tends to be tuned
 80:         # for local network conditions and fact source speed
 81:         # which would other wise not be accounted for and
 82:         # some results might get missed.
 83:         #
 84:         # We do this only if the timeout is the default 5
 85:         # seconds, so that users cli overrides will still
 86:         # get applied
 87:         #
 88:         # DDLs are required, failure to find a DDL is fatal
 89:         @ddl = DDL.new(agent)
 90:         @stats.ddl = @ddl
 91:         @timeout = @ddl.meta[:timeout] + @discovery_timeout if @timeout == 5
 92: 
 93:         # allows stderr and stdout to be overridden for testing
 94:         # but also for web apps that might not want a bunch of stuff
 95:         # generated to actual file handles
 96:         if initial_options[:stderr]
 97:           @stderr = initial_options[:stderr]
 98:         else
 99:           @stderr = STDERR
100:           @stderr.sync = true
101:         end
102: 
103:         if initial_options[:stdout]
104:           @stdout = initial_options[:stdout]
105:         else
106:           @stdout = STDOUT
107:           @stdout.sync = true
108:         end
109:       end

Public Instance methods

Sets the agent filter

[Source]

     # File lib/mcollective/rpc/client.rb, line 372
372:       def agent_filter(agent)
373:         @filter["agent"] << agent
374:         @filter["agent"].compact!
375:         reset
376:       end

[Source]

     # File lib/mcollective/rpc/client.rb, line 651
651:       def aggregate_reply(reply, aggregate)
652:         return nil unless aggregate
653: 
654:         aggregate.call_functions(reply)
655:         return aggregate
656:       rescue Exception => e
657:         Log.error("Failed to calculate aggregate summaries for reply from %s, calculating summaries disabled: %s: %s (%s)" % [reply[:senderid], e.backtrace.first, e.to_s, e.class])
658:         return nil
659:       end

Sets the batch size, if the size is set to 0 that will disable batch mode

[Source]

     # File lib/mcollective/rpc/client.rb, line 572
572:       def batch_size=(limit)
573:         raise "Can only set batch size if direct addressing is supported" unless Config.instance.direct_addressing
574: 
575:         @batch_size = Integer(limit)
576:         @batch_mode = @batch_size > 0
577:       end

[Source]

     # File lib/mcollective/rpc/client.rb, line 579
579:       def batch_sleep_time=(time)
580:         raise "Can only set batch sleep time if direct addressing is supported" unless Config.instance.direct_addressing
581: 
582:         @batch_sleep_time = Float(time)
583:       end

Handles traditional calls to the remote agents with full stats blocks, non blocks and everything else supported.

Other methods of calling the nodes can reuse this code by for example specifying custom options and discovery data

[Source]

     # File lib/mcollective/rpc/client.rb, line 779
779:       def call_agent(action, args, opts, disc=:auto, &block)
780:         # Handle fire and forget requests and make sure
781:         # the :process_results value is set appropriately
782:         #
783:         # specific reply-to requests should be treated like
784:         # fire and forget since the client will never get
785:         # the responses
786:         if args[:process_results] == false || @reply_to
787:           return fire_and_forget_request(action, args)
788:         else
789:           args[:process_results] = true
790:         end
791: 
792:         # Do discovery when no specific discovery array is given
793:         #
794:         # If an array is given set the force_direct_request hint that
795:         # will tell the message object to be a direct request one
796:         if disc == :auto
797:           discovered = discover
798:         else
799:           @force_direct_request = true if Config.instance.direct_addressing
800:           discovered = disc
801:         end
802: 
803:         req = new_request(action.to_s, args)
804: 
805:         message = Message.new(req, nil, {:agent => @agent, :type => :request, :collective => @collective, :filter => opts[:filter], :options => opts})
806:         message.discovered_hosts = discovered.clone
807: 
808:         results = []
809:         respcount = 0
810: 
811:         if discovered.size > 0
812:           message.type = :direct_request if @force_direct_request
813: 
814:           if @progress && !block_given?
815:             twirl = Progress.new
816:             @stdout.puts
817:             @stdout.print twirl.twirl(respcount, discovered.size)
818:           end
819: 
820:           aggregate = load_aggregate_functions(action, @ddl)
821: 
822:           @client.req(message) do |resp|
823:             respcount += 1
824: 
825:             if block_given?
826:               aggregate = process_results_with_block(action, resp, block, aggregate)
827:             else
828:               @stdout.print twirl.twirl(respcount, discovered.size) if @progress
829: 
830:               result, aggregate = process_results_without_block(resp, action, aggregate)
831: 
832:               results << result
833:             end
834:           end
835: 
836:           @stats.aggregate_summary = aggregate.summarize if aggregate
837:           @stats.aggregate_failures = aggregate.failed if aggregate
838:           @stats.client_stats = @client.stats
839:         else
840:           @stderr.print("\nNo request sent, we did not discover any nodes.")
841:         end
842: 
843:         @stats.finish_request
844: 
845:         RPC.stats(@stats)
846: 
847:         @stdout.print("\n\n") if @progress
848: 
849:         if block_given?
850:           return stats
851:         else
852:           return [results].flatten
853:         end
854:       end

Calls an agent in a way very similar to call_agent but it supports batching the queries to the network.

The result sets, stats, block handling etc is all exactly like you would expect from normal call_agent.

This is used by method_missing and works only with direct addressing mode

[Source]

     # File lib/mcollective/rpc/client.rb, line 694
694:       def call_agent_batched(action, args, opts, batch_size, sleep_time, &block)
695:         raise "Batched requests requires direct addressing" unless Config.instance.direct_addressing
696:         raise "Cannot bypass result processing for batched requests" if args[:process_results] == false
697: 
698:         batch_size = Integer(batch_size)
699:         sleep_time = Float(sleep_time)
700: 
701:         Log.debug("Calling #{agent}##{action} in batches of #{batch_size} with sleep time of #{sleep_time}")
702: 
703:         @force_direct_request = true
704: 
705:         discovered = discover
706:         results = []
707:         respcount = 0
708: 
709:         if discovered.size > 0
710:           req = new_request(action.to_s, args)
711: 
712:           aggregate = load_aggregate_functions(action, @ddl)
713: 
714:           if @progress && !block_given?
715:             twirl = Progress.new
716:             @stdout.puts
717:             @stdout.print twirl.twirl(respcount, discovered.size)
718:           end
719: 
720:           @stats.requestid = nil
721: 
722:           discovered.in_groups_of(batch_size) do |hosts, last_batch|
723:             message = Message.new(req, nil, {:agent => @agent, :type => :direct_request, :collective => @collective, :filter => opts[:filter], :options => opts})
724: 
725:             # first time round we let the Message object create a request id
726:             # we then re-use it for future requests to keep auditing sane etc
727:             @stats.requestid = message.create_reqid unless @stats.requestid
728:             message.requestid = @stats.requestid
729: 
730:             message.discovered_hosts = hosts.clone.compact
731: 
732:             @client.req(message) do |resp|
733:               respcount += 1
734: 
735:               if block_given?
736:                 aggregate = process_results_with_block(action, resp, block, aggregate)
737:               else
738:                 @stdout.print twirl.twirl(respcount, discovered.size) if @progress
739: 
740:                 result, aggregate = process_results_without_block(resp, action, aggregate)
741: 
742:                 results << result
743:               end
744:             end
745: 
746:             @stats.noresponsefrom.concat @client.stats[:noresponsefrom]
747:             @stats.responses += @client.stats[:responses]
748:             @stats.blocktime += @client.stats[:blocktime] + sleep_time
749:             @stats.totaltime += @client.stats[:totaltime]
750:             @stats.discoverytime += @client.stats[:discoverytime]
751: 
752:             sleep sleep_time unless last_batch
753:           end
754: 
755:           @stats.aggregate_summary = aggregate.summarize if aggregate
756:           @stats.aggregate_failures = aggregate.failed if aggregate
757:         else
758:           @stderr.print("\nNo request sent, we did not discover any nodes.")
759:         end
760: 
761:         @stats.finish_request
762: 
763:         RPC.stats(@stats)
764: 
765:         @stdout.print("\n") if @progress
766: 
767:         if block_given?
768:           return stats
769:         else
770:           return [results].flatten
771:         end
772:       end

Sets the class filter

[Source]

     # File lib/mcollective/rpc/client.rb, line 348
348:       def class_filter(klass)
349:         @filter["cf_class"] << klass
350:         @filter["cf_class"].compact!
351:         reset
352:       end

Sets the collective we are communicating with

[Source]

     # File lib/mcollective/rpc/client.rb, line 537
537:       def collective=(c)
538:         raise "Unknown collective #{c}" unless Config.instance.collectives.include?(c)
539: 
540:         @collective = c
541:         @client.options = options
542:         reset
543:       end

Set a compound filter

[Source]

     # File lib/mcollective/rpc/client.rb, line 386
386:       def compound_filter(filter)
387:         @filter["compound"] <<  Matcher.create_compound_callstack(filter)
388:         reset
389:       end

Constructs custom requests with custom filters and discovery data the idea is that this would be used in web applications where you might be using a cached copy of data provided by a registration agent to figure out on your own what nodes will be responding and what your filter would be.

This will help you essentially short circuit the traditional cycle of:

mc discover / call / wait for discovered nodes

by doing discovery however you like, contructing a filter and a list of nodes you expect responses from.

Other than that it will work exactly like a normal call, blocks will behave the same way, stats will be handled the same way etcetc

If you just wanted to contact one machine for example with a client that already has other filter options setup you can do:

puppet.custom_request("runonce", {}, ["your.box.com"], {:identity => "your.box.com"})

This will do runonce action on just ‘your.box.com’, no discovery will be done and after receiving just one response it will stop waiting for responses

If direct_addressing is enabled in the config file you can provide an empty hash as a filter, this will force that request to be a directly addressed request which technically does not need filters. If you try to use this mode with direct addressing disabled an exception will be raise

[Source]

     # File lib/mcollective/rpc/client.rb, line 275
275:       def custom_request(action, args, expected_agents, filter = {}, &block)
276:         @ddl.validate_rpc_request(action, args) if @ddl
277: 
278:         if filter == {} && !Config.instance.direct_addressing
279:           raise "Attempted to do a filterless custom_request without direct_addressing enabled, preventing unexpected call to all nodes"
280:         end
281: 
282:         @stats.reset
283: 
284:         custom_filter = Util.empty_filter
285:         custom_options = options.clone
286: 
287:         # merge the supplied filter with the standard empty one
288:         # we could just use the merge method but I want to be sure
289:         # we dont merge in stuff that isnt actually valid
290:         ["identity", "fact", "agent", "cf_class", "compound"].each do |ftype|
291:           if filter.include?(ftype)
292:             custom_filter[ftype] = [filter[ftype], custom_filter[ftype]].flatten
293:           end
294:         end
295: 
296:         # ensure that all filters at least restrict the call to the agent we're a proxy for
297:         custom_filter["agent"] << @agent unless custom_filter["agent"].include?(@agent)
298:         custom_options[:filter] = custom_filter
299: 
300:         # Fake out the stats discovery would have put there
301:         @stats.discovered_agents([expected_agents].flatten)
302: 
303:         # Handle fire and forget requests
304:         #
305:         # If a specific reply-to was set then from the client perspective this should
306:         # be a fire and forget request too since no response will ever reach us - it
307:         # will go to the reply-to destination
308:         if args[:process_results] == false || @reply_to
309:           return fire_and_forget_request(action, args, custom_filter)
310:         end
311: 
312:         # Now do a call pretty much exactly like in method_missing except with our own
313:         # options and discovery magic
314:         if block_given?
315:           call_agent(action, args, custom_options, [expected_agents].flatten) do |r|
316:             block.call(r)
317:           end
318:         else
319:           call_agent(action, args, custom_options, [expected_agents].flatten)
320:         end
321:       end

Disconnects cleanly from the middleware

[Source]

     # File lib/mcollective/rpc/client.rb, line 112
112:       def disconnect
113:         @client.disconnect
114:       end

Does discovery based on the filters set, if a discovery was previously done return that else do a new discovery.

Alternatively if identity filters are given and none of them are regular expressions then just use the provided data as discovered data, avoiding discovery

Discovery can be forced if direct_addressing is enabled by passing in an array of nodes with :nodes or JSON data like those produced by mcollective RPC JSON output using :json

Will show a message indicating its doing discovery if running verbose or if the :verbose flag is passed in.

Use reset to force a new discovery

[Source]

     # File lib/mcollective/rpc/client.rb, line 418
418:       def discover(flags={})
419:         flags.keys.each do |key|
420:           raise "Unknown option #{key} passed to discover" unless [:verbose, :hosts, :nodes, :json].include?(key)
421:         end
422: 
423:         flags.include?(:verbose) ? verbose = flags[:verbose] : verbose = @verbose
424: 
425:         verbose = false unless @output_format == :console
426: 
427:         # flags[:nodes] and flags[:hosts] are the same thing, we should never have
428:         # allowed :hosts as that was inconsistent with the established terminology
429:         flags[:nodes] = flags.delete(:hosts) if flags.include?(:hosts)
430: 
431:         reset if flags[:nodes] || flags[:json]
432: 
433:         unless @discovered_agents
434:           # if either hosts or JSON is supplied try to figure out discovery data from there
435:           # if direct_addressing is not enabled this is a critical error as the user might
436:           # not have supplied filters so raise an exception
437:           if flags[:nodes] || flags[:json]
438:             raise "Can only supply discovery data if direct_addressing is enabled" unless Config.instance.direct_addressing
439: 
440:             hosts = []
441: 
442:             if flags[:nodes]
443:               hosts = Helpers.extract_hosts_from_array(flags[:nodes])
444:             elsif flags[:json]
445:               hosts = Helpers.extract_hosts_from_json(flags[:json])
446:             end
447: 
448:             raise "Could not find any hosts in discovery data provided" if hosts.empty?
449: 
450:             @discovered_agents = hosts
451:             @force_direct_request = true
452: 
453:           # if an identity filter is supplied and it is all strings no regex we can use that
454:           # as discovery data, technically the identity filter is then redundant if we are
455:           # in direct addressing mode and we could empty it out but this use case should
456:           # only really be for a few -I's on the CLI
457:           #
458:           # For safety we leave the filter in place for now, that way we can support this
459:           # enhancement also in broadcast mode.
460:           #
461:           # This is only needed for the 'mc' discovery method, other methods might change
462:           # the concept of identity to mean something else so we should pass the full
463:           # identity filter to them
464:           elsif options[:filter]["identity"].size > 0 && @discovery_method == "mc"
465:             regex_filters = options[:filter]["identity"].select{|i| i.match("^\/")}.size
466: 
467:             if regex_filters == 0
468:               @discovered_agents = options[:filter]["identity"].clone
469:               @force_direct_request = true if Config.instance.direct_addressing
470:             end
471:           end
472:         end
473: 
474:         # All else fails we do it the hard way using a traditional broadcast
475:         unless @discovered_agents
476:           @stats.time_discovery :start
477: 
478:           @client.options = options
479: 
480:           # if compound filters are used the only real option is to use the mc
481:           # discovery plugin since its the only capable of using data queries etc
482:           # and we do not want to degrade that experience just to allow compounds
483:           # on other discovery plugins the UX would be too bad raising complex sets
484:           # of errors etc.
485:           @client.discoverer.force_discovery_method_by_filter(options[:filter])
486: 
487:           if verbose
488:             actual_timeout = @client.discoverer.discovery_timeout(discovery_timeout, options[:filter])
489: 
490:             if actual_timeout > 0
491:               @stderr.print("Discovering hosts using the %s method for %d second(s) .... " % [@client.discoverer.discovery_method, actual_timeout])
492:             else
493:               @stderr.print("Discovering hosts using the %s method .... " % [@client.discoverer.discovery_method])
494:             end
495:           end
496: 
497:           # if the requested limit is a pure number and not a percent
498:           # and if we're configured to use the first found hosts as the
499:           # limit method then pass in the limit thus minimizing the amount
500:           # of work we do in the discover phase and speeding it up significantly
501:           if @limit_method == :first and @limit_targets.is_a?(Fixnum)
502:             @discovered_agents = @client.discover(@filter, discovery_timeout, @limit_targets)
503:           else
504:             @discovered_agents = @client.discover(@filter, discovery_timeout)
505:           end
506: 
507:           @stderr.puts(@discovered_agents.size) if verbose
508: 
509:           @force_direct_request = @client.discoverer.force_direct_mode?
510: 
511:           @stats.time_discovery :end
512:         end
513: 
514:         @stats.discovered_agents(@discovered_agents)
515:         RPC.discovered(@discovered_agents)
516: 
517:         @discovered_agents
518:       end

[Source]

     # File lib/mcollective/rpc/client.rb, line 328
328:       def discovery_method=(method)
329:         @discovery_method = method
330: 
331:         if @initial_options[:discovery_options]
332:           @discovery_options = @initial_options[:discovery_options]
333:         else
334:           @discovery_options.clear
335:         end
336: 
337:         @client.options = options
338:         @discovery_timeout = discovery_timeout
339:         reset
340:       end

[Source]

     # File lib/mcollective/rpc/client.rb, line 342
342:       def discovery_options=(options)
343:         @discovery_options = [options].flatten
344:         reset
345:       end

[Source]

     # File lib/mcollective/rpc/client.rb, line 323
323:       def discovery_timeout
324:         return @initial_options[:disctimeout] if @initial_options[:disctimeout]
325:         return @client.discoverer.ddl.meta[:timeout]
326:       end

Sets the fact filter

[Source]

     # File lib/mcollective/rpc/client.rb, line 355
355:       def fact_filter(fact, value=nil, operator="=")
356:         return if fact.nil?
357:         return if fact == false
358: 
359:         if value.nil?
360:           parsed = Util.parse_fact_string(fact)
361:           @filter["fact"] << parsed unless parsed == false
362:         else
363:           parsed = Util.parse_fact_string("#{fact}#{operator}#{value}")
364:           @filter["fact"] << parsed unless parsed == false
365:         end
366: 
367:         @filter["fact"].compact!
368:         reset
369:       end

for requests that do not care for results just return the request id and don‘t do any of the response processing.

We send the :process_results flag with to the nodes so they can make decisions based on that.

Should only be called via method_missing

[Source]

     # File lib/mcollective/rpc/client.rb, line 674
674:       def fire_and_forget_request(action, args, filter=nil)
675:         @ddl.validate_rpc_request(action, args) if @ddl
676: 
677:         req = new_request(action.to_s, args)
678: 
679:         filter = options[:filter] unless filter
680: 
681:         message = Message.new(req, nil, {:agent => @agent, :type => :request, :collective => @collective, :filter => filter, :options => options})
682:         message.reply_to = @reply_to if @reply_to
683: 
684:         return @client.sendreq(message, nil)
685:       end

Returns help for an agent if a DDL was found

[Source]

     # File lib/mcollective/rpc/client.rb, line 117
117:       def help(template)
118:         @ddl.help(template)
119:       end

Sets the identity filter

[Source]

     # File lib/mcollective/rpc/client.rb, line 379
379:       def identity_filter(identity)
380:         @filter["identity"] << identity
381:         @filter["identity"].compact!
382:         reset
383:       end

Sets and sanity check the limit_method variable used to determine how to limit targets if limit_targets is set

[Source]

     # File lib/mcollective/rpc/client.rb, line 563
563:       def limit_method=(method)
564:         method = method.to_sym unless method.is_a?(Symbol)
565: 
566:         raise "Unknown limit method #{method} must be :random or :first" unless [:random, :first].include?(method)
567: 
568:         @limit_method = method
569:       end

Sets and sanity checks the limit_targets variable used to restrict how many nodes we‘ll target

[Source]

     # File lib/mcollective/rpc/client.rb, line 547
547:       def limit_targets=(limit)
548:         if limit.is_a?(String)
549:           raise "Invalid limit specified: #{limit} valid limits are /^\d+%*$/" unless limit =~ /^\d+%*$/
550: 
551:           begin
552:             @limit_targets = Integer(limit)
553:           rescue
554:             @limit_targets = limit
555:           end
556:         else
557:           @limit_targets = Integer(limit)
558:         end
559:       end

[Source]

     # File lib/mcollective/rpc/client.rb, line 640
640:       def load_aggregate_functions(action, ddl)
641:         return nil unless ddl
642:         return nil unless ddl.action_interface(action).keys.include?(:aggregate)
643: 
644:         return Aggregate.new(ddl.action_interface(action))
645: 
646:       rescue => e
647:         Log.error("Failed to load aggregate functions, calculating summaries disabled: %s: %s (%s)" % [e.backtrace.first, e.to_s, e.class])
648:         return nil
649:       end

Magic handler to invoke remote methods

Once the stub is created using the constructor or the RPC#rpcclient helper you can call remote actions easily:

  ret = rpc.echo(:msg => "hello world")

This will call the ‘echo’ action of the ‘rpctest’ agent and return the result as an array, the array will be a simplified result set from the usual full MCollective::Client#req with additional error codes and error text:

{

  :sender => "remote.box.com",
  :statuscode => 0,
  :statusmsg => "OK",
  :data => "hello world"

}

If :statuscode is 0 then everything went find, if it‘s 1 then you supplied the correct arguments etc but the request could not be completed, you‘ll find a human parsable reason in :statusmsg then.

Codes 2 to 5 maps directly to UnknownRPCAction, MissingRPCData, InvalidRPCData and UnknownRPCError see below for a description of those, in each case :statusmsg would be the reason for failure.

To get access to the full result of the MCollective::Client#req calls you can pass in a block:

  rpc.echo(:msg => "hello world") do |resp|
     pp resp
  end

In this case resp will the result from MCollective::Client#req. Instead of returning simple text and codes as above you‘ll also need to handle the following exceptions:

UnknownRPCAction - There is no matching action on the agent MissingRPCData - You did not supply all the needed parameters for the action InvalidRPCData - The data you did supply did not pass validation UnknownRPCError - Some other error prevented the agent from running

During calls a progress indicator will be shown of how many results we‘ve received against how many nodes were discovered, you can disable this by setting progress to false:

  rpc.progress = false

This supports a 2nd mode where it will send the SimpleRPC request and never handle the responses. It‘s a bit like UDP, it sends the request with the filter attached and you only get back the requestid, you have no indication about results.

You can invoke this using:

  puts rpc.echo(:process_results => false)

This will output just the request id.

Batched processing is supported:

  printrpc rpc.ping(:batch_size => 5)

This will do everything exactly as normal but communicate to only 5 agents at a time

[Source]

     # File lib/mcollective/rpc/client.rb, line 210
210:       def method_missing(method_name, *args, &block)
211:         # set args to an empty hash if nothings given
212:         args = args[0]
213:         args = {} if args.nil?
214: 
215:         action = method_name.to_s
216: 
217:         @stats.reset
218: 
219:         @ddl.validate_rpc_request(action, args) if @ddl
220: 
221:         # if a global batch size is set just use that else set it
222:         # in the case that it was passed as an argument
223:         batch_mode = args.include?(:batch_size) || @batch_mode
224:         batch_size = args.delete(:batch_size) || @batch_size
225:         batch_sleep_time = args.delete(:batch_sleep_time) || @batch_sleep_time
226: 
227:         # if we were given a batch_size argument thats 0 and batch_mode was
228:         # determined to be on via global options etc this will allow a batch_size
229:         # of 0 to disable or batch_mode for this call only
230:         batch_mode = (batch_mode && Integer(batch_size) > 0)
231: 
232:         # Handle single target requests by doing discovery and picking
233:         # a random node.  Then do a custom request specifying a filter
234:         # that will only match the one node.
235:         if @limit_targets
236:           target_nodes = pick_nodes_from_discovered(@limit_targets)
237:           Log.debug("Picked #{target_nodes.join(',')} as limited target(s)")
238: 
239:           custom_request(action, args, target_nodes, {"identity" => /^(#{target_nodes.join('|')})$/}, &block)
240:         elsif batch_mode
241:           call_agent_batched(action, args, options, batch_size, batch_sleep_time, &block)
242:         else
243:           call_agent(action, args, options, :auto, &block)
244:         end
245:       end

Creates a suitable request hash for the SimpleRPC agent.

You‘d use this if you ever wanted to take care of sending requests on your own - perhaps via Client#sendreq if you didn‘t care for responses.

In that case you can just do:

  msg = your_rpc.new_request("some_action", :foo => :bar)
  filter = your_rpc.filter

  your_rpc.client.sendreq(msg, msg[:agent], filter)

This will send a SimpleRPC request to the action some_action with arguments :foo = :bar, it will return immediately and you will have no indication at all if the request was receieved or not

Clearly the use of this technique should be limited and done only if your code requires such a thing

[Source]

     # File lib/mcollective/rpc/client.rb, line 140
140:       def new_request(action, data)
141:         callerid = PluginManager["security_plugin"].callerid
142: 
143:         raise 'callerid received from security plugin is not valid' unless PluginManager["security_plugin"].valid_callerid?(callerid)
144: 
145:         {:agent  => @agent,
146:          :action => action,
147:          :caller => callerid,
148:          :data   => data}
149:       end

Provides a normal options hash like you would get from Optionparser

[Source]

     # File lib/mcollective/rpc/client.rb, line 522
522:       def options
523:         {:disctimeout => @discovery_timeout,
524:          :timeout => @timeout,
525:          :verbose => @verbose,
526:          :filter => @filter,
527:          :collective => @collective,
528:          :output_format => @output_format,
529:          :ttl => @ttl,
530:          :discovery_method => @discovery_method,
531:          :discovery_options => @discovery_options,
532:          :force_display_mode => @force_display_mode,
533:          :config => @config}
534:       end

Pick a number of nodes from the discovered nodes

The count should be a string that can be either just a number or a percentage like 10%

It will select nodes from the discovered list based on the rpclimitmethod configuration option which can be either :first or anything else

  - :first would be a simple way to do a distance based
    selection
  - anything else will just pick one at random
  - if random chosen, and batch-seed set, then set srand
    for the generator, and reset afterwards

[Source]

     # File lib/mcollective/rpc/client.rb, line 599
599:       def pick_nodes_from_discovered(count)
600:         if count =~ /%$/
601:           pct = Integer((discover.size * (count.to_f / 100)))
602:           pct == 0 ? count = 1 : count = pct
603:         else
604:           count = Integer(count)
605:         end
606: 
607:         return discover if discover.size <= count
608: 
609:         result = []
610: 
611:         if @limit_method == :first
612:           return discover[0, count]
613:         else
614:           # we delete from the discovered list because we want
615:           # to be sure there is no chance that the same node will
616:           # be randomly picked twice.  So we have to clone the
617:           # discovered list else this method will only ever work
618:           # once per discovery cycle and not actually return the
619:           # right nodes.
620:           haystack = discover.clone
621: 
622:           if @limit_seed
623:             haystack.sort!
624:             srand(@limit_seed)
625:           end
626: 
627:           count.times do
628:             rnd = rand(haystack.size)
629:             result << haystack.delete_at(rnd)
630:           end
631: 
632:           # Reset random number generator to fresh seed
633:           # As our seed from options is most likely short
634:           srand if @limit_seed
635:         end
636: 
637:         [result].flatten
638:       end

process client requests by calling a block on each result in this mode we do not do anything fancy with the result objects and we raise exceptions if there are problems with the data

[Source]

     # File lib/mcollective/rpc/client.rb, line 879
879:       def process_results_with_block(action, resp, block, aggregate)
880:         @stats.node_responded(resp[:senderid])
881: 
882:         result = rpc_result_from_reply(@agent, action, resp)
883:         aggregate = aggregate_reply(result, aggregate) if aggregate
884: 
885:         if resp[:body][:statuscode] == 0 || resp[:body][:statuscode] == 1
886:           @stats.ok if resp[:body][:statuscode] == 0
887:           @stats.fail if resp[:body][:statuscode] == 1
888:           @stats.time_block_execution :start
889: 
890:           case block.arity
891:             when 1
892:               block.call(resp)
893:             when 2
894:               block.call(resp, result)
895:           end
896: 
897:           @stats.time_block_execution :end
898:         else
899:           @stats.fail
900: 
901:           case resp[:body][:statuscode]
902:             when 2
903:               raise UnknownRPCAction, resp[:body][:statusmsg]
904:             when 3
905:               raise MissingRPCData, resp[:body][:statusmsg]
906:             when 4
907:               raise InvalidRPCData, resp[:body][:statusmsg]
908:             when 5
909:               raise UnknownRPCError, resp[:body][:statusmsg]
910:           end
911:         end
912: 
913:         return aggregate
914:       end

Handles result sets that has no block associated, sets fails and ok in the stats object and return a hash of the response to send to the caller

[Source]

     # File lib/mcollective/rpc/client.rb, line 859
859:       def process_results_without_block(resp, action, aggregate)
860:         @stats.node_responded(resp[:senderid])
861: 
862:         result = rpc_result_from_reply(@agent, action, resp)
863:         aggregate = aggregate_reply(result, aggregate) if aggregate
864: 
865:         if resp[:body][:statuscode] == 0 || resp[:body][:statuscode] == 1
866:           @stats.ok if resp[:body][:statuscode] == 0
867:           @stats.fail if resp[:body][:statuscode] == 1
868:         else
869:           @stats.fail
870:         end
871: 
872:         [result, aggregate]
873:       end

Resets various internal parts of the class, most importantly it clears out the cached discovery

[Source]

     # File lib/mcollective/rpc/client.rb, line 393
393:       def reset
394:         @discovered_agents = nil
395:       end

Reet the filter to an empty one

[Source]

     # File lib/mcollective/rpc/client.rb, line 398
398:       def reset_filter
399:         @filter = Util.empty_filter
400:         agent_filter @agent
401:       end

[Source]

     # File lib/mcollective/rpc/client.rb, line 661
661:       def rpc_result_from_reply(agent, action, reply)
662:         Result.new(agent, action, {:sender => reply[:senderid], :statuscode => reply[:body][:statuscode],
663:                                    :statusmsg => reply[:body][:statusmsg], :data => reply[:body][:data]})
664:       end

[Validate]