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.
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_targets | [R] | |
output_format | [R] | |
progress | [RW] | |
reply_to | [RW] | |
stats | [R] | |
timeout | [RW] | |
ttl | [RW] | |
verbose | [RW] |
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
# 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] 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: @output_format = initial_options[:output_format] || :console 53: @force_direct_request = false 54: @reply_to = initial_options[:reply_to] 55: @discovery_method = initial_options[:discovery_method] 56: @discovery_options = initial_options[:discovery_options] || [] 57: 58: @batch_size = Integer(initial_options[:batch_size] || 0) 59: @batch_sleep_time = Float(initial_options[:batch_sleep_time] || 1) 60: @batch_mode = @batch_size > 0 61: 62: agent_filter agent 63: 64: @client = MCollective::Client.new(@config) 65: @client.options = initial_options 66: 67: @discovery_timeout = discovery_timeout 68: 69: @collective = @client.collective 70: @ttl = initial_options[:ttl] || Config.instance.ttl 71: 72: # if we can find a DDL for the service override 73: # the timeout of the client so we always magically 74: # wait appropriate amounts of time. 75: # 76: # We add the discovery timeout to the ddl supplied 77: # timeout as the discovery timeout tends to be tuned 78: # for local network conditions and fact source speed 79: # which would other wise not be accounted for and 80: # some results might get missed. 81: # 82: # We do this only if the timeout is the default 5 83: # seconds, so that users cli overrides will still 84: # get applied 85: begin 86: @ddl = DDL.new(agent) 87: @timeout = @ddl.meta[:timeout] + @discovery_timeout if @timeout == 5 88: rescue Exception => e 89: Log.debug("Could not find DDL: #{e}") 90: @ddl = nil 91: end 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
Sets the agent filter
# File lib/mcollective/rpc/client.rb, line 376 376: def agent_filter(agent) 377: @filter["agent"] << agent 378: @filter["agent"].compact! 379: reset 380: end
Sets the batch size, if the size is set to 0 that will disable batch mode
# File lib/mcollective/rpc/client.rb, line 568 568: def batch_size=(limit) 569: raise "Can only set batch size if direct addressing is supported" unless Config.instance.direct_addressing 570: 571: @batch_size = Integer(limit) 572: @batch_mode = @batch_size > 0 573: end
# File lib/mcollective/rpc/client.rb, line 575 575: def batch_sleep_time=(time) 576: raise "Can only set batch sleep time if direct addressing is supported" unless Config.instance.direct_addressing 577: 578: @batch_sleep_time = Float(time) 579: end
Sets the class filter
# File lib/mcollective/rpc/client.rb, line 352 352: def class_filter(klass) 353: @filter["cf_class"] << klass 354: @filter["cf_class"].compact! 355: reset 356: end
Sets the collective we are communicating with
# File lib/mcollective/rpc/client.rb, line 533 533: def collective=(c) 534: raise "Unknown collective #{c}" unless Config.instance.collectives.include?(c) 535: 536: @collective = c 537: @client.options = options 538: reset 539: end
Set a compound filter
# File lib/mcollective/rpc/client.rb, line 390 390: def compound_filter(filter) 391: @filter["compound"] << Matcher.create_compound_callstack(filter) 392: reset 393: 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
# File lib/mcollective/rpc/client.rb, line 279 279: def custom_request(action, args, expected_agents, filter = {}, &block) 280: @ddl.validate_rpc_request(action, args) if @ddl 281: 282: if filter == {} && !Config.instance.direct_addressing 283: raise "Attempted to do a filterless custom_request without direct_addressing enabled, preventing unexpected call to all nodes" 284: end 285: 286: @stats.reset 287: 288: custom_filter = Util.empty_filter 289: custom_options = options.clone 290: 291: # merge the supplied filter with the standard empty one 292: # we could just use the merge method but I want to be sure 293: # we dont merge in stuff that isnt actually valid 294: ["identity", "fact", "agent", "cf_class", "compound"].each do |ftype| 295: if filter.include?(ftype) 296: custom_filter[ftype] = [filter[ftype], custom_filter[ftype]].flatten 297: end 298: end 299: 300: # ensure that all filters at least restrict the call to the agent we're a proxy for 301: custom_filter["agent"] << @agent unless custom_filter["agent"].include?(@agent) 302: custom_options[:filter] = custom_filter 303: 304: # Fake out the stats discovery would have put there 305: @stats.discovered_agents([expected_agents].flatten) 306: 307: # Handle fire and forget requests 308: # 309: # If a specific reply-to was set then from the client perspective this should 310: # be a fire and forget request too since no response will ever reach us - it 311: # will go to the reply-to destination 312: if args[:process_results] == false || @reply_to 313: return fire_and_forget_request(action, args, custom_filter) 314: end 315: 316: # Now do a call pretty much exactly like in method_missing except with our own 317: # options and discovery magic 318: if block_given? 319: call_agent(action, args, custom_options, [expected_agents].flatten) do |r| 320: block.call(r) 321: end 322: else 323: call_agent(action, args, custom_options, [expected_agents].flatten) 324: end 325: end
Disconnects cleanly from the middleware
# 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
# File lib/mcollective/rpc/client.rb, line 422 422: def discover(flags={}) 423: flags.keys.each do |key| 424: raise "Unknown option #{key} passed to discover" unless [:verbose, :hosts, :nodes, :json].include?(key) 425: end 426: 427: flags.include?(:verbose) ? verbose = flags[:verbose] : verbose = @verbose 428: 429: verbose = false unless @output_format == :console 430: 431: # flags[:nodes] and flags[:hosts] are the same thing, we should never have 432: # allowed :hosts as that was inconsistent with the established terminology 433: flags[:nodes] = flags.delete(:hosts) if flags.include?(:hosts) 434: 435: reset if flags[:nodes] || flags[:json] 436: 437: unless @discovered_agents 438: # if either hosts or JSON is supplied try to figure out discovery data from there 439: # if direct_addressing is not enabled this is a critical error as the user might 440: # not have supplied filters so raise an exception 441: if flags[:nodes] || flags[:json] 442: raise "Can only supply discovery data if direct_addressing is enabled" unless Config.instance.direct_addressing 443: 444: hosts = [] 445: 446: if flags[:nodes] 447: hosts = Helpers.extract_hosts_from_array(flags[:nodes]) 448: elsif flags[:json] 449: hosts = Helpers.extract_hosts_from_json(flags[:json]) 450: end 451: 452: raise "Could not find any hosts in discovery data provided" if hosts.empty? 453: 454: @discovered_agents = hosts 455: @force_direct_request = true 456: 457: # if an identity filter is supplied and it is all strings no regex we can use that 458: # as discovery data, technically the identity filter is then redundant if we are 459: # in direct addressing mode and we could empty it out but this use case should 460: # only really be for a few -I's on the CLI 461: # 462: # For safety we leave the filter in place for now, that way we can support this 463: # enhancement also in broadcast mode 464: elsif options[:filter]["identity"].size > 0 465: 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: # if compound filters are used the only real option is to use the mc 479: # discovery plugin since its the only capable of using data queries etc 480: # and we do not want to degrade that experience just to allow compounds 481: # on other discovery plugins the UX would be too bad raising complex sets 482: # of errors etc. 483: @client.discoverer.force_discovery_method_by_filter(options[:filter]) 484: 485: actual_timeout = options[:disctimeout] + @client.timeout_for_compound_filter(options[:filter]["compound"]) 486: if actual_timeout > 0 487: @stderr.print("Discovering hosts using the %s method for %d second(s) .... " % [@client.discoverer.discovery_method, actual_timeout]) if verbose 488: else 489: @stderr.print("Discovering hosts using the %s method .... " % [@client.discoverer.discovery_method]) if verbose 490: end 491: 492: @client.options = options 493: 494: # if the requested limit is a pure number and not a percent 495: # and if we're configured to use the first found hosts as the 496: # limit method then pass in the limit thus minimizing the amount 497: # of work we do in the discover phase and speeding it up significantly 498: if @limit_method == :first and @limit_targets.is_a?(Fixnum) 499: @discovered_agents = @client.discover(@filter, options[:disctimeout], @limit_targets) 500: else 501: @discovered_agents = @client.discover(@filter, options[:disctimeout]) 502: end 503: 504: @stderr.puts(@discovered_agents.size) if verbose 505: 506: @force_direct_request = @client.discoverer.force_direct_mode? 507: 508: @stats.time_discovery :end 509: end 510: 511: @stats.discovered_agents(@discovered_agents) 512: RPC.discovered(@discovered_agents) 513: 514: @discovered_agents 515: end
# File lib/mcollective/rpc/client.rb, line 332 332: def discovery_method=(method) 333: @discovery_method = method 334: 335: if @initial_options[:discovery_options] 336: @discovery_options = @initial_options[:discovery_options] 337: else 338: @discovery_options.clear 339: end 340: 341: @client.options = options 342: @discovery_timeout = discovery_timeout 343: reset 344: end
# File lib/mcollective/rpc/client.rb, line 346 346: def discovery_options=(options) 347: @discovery_options = [options].flatten 348: reset 349: end
# File lib/mcollective/rpc/client.rb, line 327 327: def discovery_timeout 328: return @initial_options[:disctimeout] if @initial_options[:disctimeout] 329: return @client.discoverer.ddl.meta[:timeout] 330: end
Sets the fact filter
# File lib/mcollective/rpc/client.rb, line 359 359: def fact_filter(fact, value=nil, operator="=") 360: return if fact.nil? 361: return if fact == false 362: 363: if value.nil? 364: parsed = Util.parse_fact_string(fact) 365: @filter["fact"] << parsed unless parsed == false 366: else 367: parsed = Util.parse_fact_string("#{fact}#{operator}#{value}") 368: @filter["fact"] << parsed unless parsed == false 369: end 370: 371: @filter["fact"].compact! 372: reset 373: end
Sets the identity filter
# File lib/mcollective/rpc/client.rb, line 383 383: def identity_filter(identity) 384: @filter["identity"] << identity 385: @filter["identity"].compact! 386: reset 387: end
Sets and sanity check the limit_method variable used to determine how to limit targets if limit_targets is set
# File lib/mcollective/rpc/client.rb, line 559 559: def limit_method=(method) 560: method = method.to_sym unless method.is_a?(Symbol) 561: 562: raise "Unknown limit method #{method} must be :random or :first" unless [:random, :first].include?(method) 563: 564: @limit_method = method 565: end
Sets and sanity checks the limit_targets variable used to restrict how many nodes we‘ll target
# File lib/mcollective/rpc/client.rb, line 543 543: def limit_targets=(limit) 544: if limit.is_a?(String) 545: raise "Invalid limit specified: #{limit} valid limits are /^\d+%*$/" unless limit =~ /^\d+%*$/ 546: 547: begin 548: @limit_targets = Integer(limit) 549: rescue 550: @limit_targets = limit 551: end 552: else 553: @limit_targets = Integer(limit) 554: end 555: 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
# File lib/mcollective/rpc/client.rb, line 214 214: def method_missing(method_name, *args, &block) 215: # set args to an empty hash if nothings given 216: args = args[0] 217: args = {} if args.nil? 218: 219: action = method_name.to_s 220: 221: @stats.reset 222: 223: @ddl.validate_rpc_request(action, args) if @ddl 224: 225: # if a global batch size is set just use that else set it 226: # in the case that it was passed as an argument 227: batch_mode = args.include?(:batch_size) || @batch_mode 228: batch_size = args.delete(:batch_size) || @batch_size 229: batch_sleep_time = args.delete(:batch_sleep_time) || @batch_sleep_time 230: 231: # if we were given a batch_size argument thats 0 and batch_mode was 232: # determined to be on via global options etc this will allow a batch_size 233: # of 0 to disable or batch_mode for this call only 234: batch_mode = (batch_mode && Integer(batch_size) > 0) 235: 236: # Handle single target requests by doing discovery and picking 237: # a random node. Then do a custom request specifying a filter 238: # that will only match the one node. 239: if @limit_targets 240: target_nodes = pick_nodes_from_discovered(@limit_targets) 241: Log.debug("Picked #{target_nodes.join(',')} as limited target(s)") 242: 243: custom_request(action, args, target_nodes, {"identity" => /^(#{target_nodes.join('|')})$/}, &block) 244: elsif batch_mode 245: call_agent_batched(action, args, options, batch_size, batch_sleep_time, &block) 246: else 247: call_agent(action, args, options, :auto, &block) 248: end 249: 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
# File lib/mcollective/rpc/client.rb, line 144 144: def new_request(action, data) 145: callerid = PluginManager["security_plugin"].callerid 146: 147: raise 'callerid received from security plugin is not valid' unless PluginManager["security_plugin"].valid_callerid?(callerid) 148: 149: {:agent => @agent, 150: :action => action, 151: :caller => callerid, 152: :data => data} 153: end
Provides a normal options hash like you would get from Optionparser
# File lib/mcollective/rpc/client.rb, line 519 519: def options 520: {:disctimeout => @discovery_timeout, 521: :timeout => @timeout, 522: :verbose => @verbose, 523: :filter => @filter, 524: :collective => @collective, 525: :output_format => @output_format, 526: :ttl => @ttl, 527: :discovery_method => @discovery_method, 528: :discovery_options => @discovery_options, 529: :config => @config} 530: end
Resets various internal parts of the class, most importantly it clears out the cached discovery
# File lib/mcollective/rpc/client.rb, line 397 397: def reset 398: @discovered_agents = nil 399: end