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Add experimental rabbitmq connector

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commit 5998f8694e0ae48433a0910d94b5cdf20417f2fc 1 parent 032635d
@ripienaar authored
Showing with 302 additions and 0 deletions.
  1. +302 −0 connector/rabbitmq/rabbitmq.rb
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302 connector/rabbitmq/rabbitmq.rb
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+require 'stomp'
+
+module MCollective
+ module Connector
+ class Rabbitmq<Base
+ attr_reader :connection
+
+ class EventLogger
+ def on_connecting(params=nil)
+ Log.info("TCP Connection attempt %d to %s" % [params[:cur_conattempts], stomp_url(params)])
+ rescue
+ end
+
+ def on_connected(params=nil)
+ Log.info("Conncted to #{stomp_url(params)}")
+ rescue
+ end
+
+ def on_disconnect(params=nil)
+ Log.info("Disconnected from #{stomp_url(params)}")
+ rescue
+ end
+
+ def on_connectfail(params=nil)
+ Log.info("TCP Connection to #{stomp_url(params)} failed on attempt #{params[:cur_conattempts]}")
+ rescue
+ end
+
+ def on_miscerr(params, errstr)
+ Log.error("Unexpected error on connection #{stomp_url(params)}: #{errstr}")
+ rescue
+ end
+
+ def on_ssl_connecting(params)
+ Log.info("Estblishing SSL session with #{stomp_url(params)}")
+ rescue
+ end
+
+ def on_ssl_connected(params)
+ Log.info("SSL session established with #{stomp_url(params)}")
+ rescue
+ end
+
+ def on_ssl_connectfail(params)
+ Log.error("SSL session creation with #{stomp_url(params)} failed: #{params[:ssl_exception]}")
+ end
+
+ def stomp_url(params)
+ "%s://%s@%s:%d" % [ params[:cur_ssl] ? "stomp+ssl" : "stomp", params[:cur_login], params[:cur_host], params[:cur_port]]
+ end
+ end
+
+ def initialize
+ @config = Config.instance
+ @subscriptions = []
+ @base64 = false
+ end
+
+ # Connects to the RabbitMQ middleware
+ def connect(connector = ::Stomp::Connection)
+ if @connection
+ Log.debug("Already connection, not re-initializing connection")
+ return
+ end
+
+ begin
+ @base64 = get_bool_option("rabbitmq.base64", false)
+
+ pools = @config.pluginconf["rabbitmq.pool.size"].to_i
+ hosts = []
+
+ 1.upto(pools) do |poolnum|
+ host = {}
+
+ host[:host] = get_option("rabbitmq.pool.#{poolnum}.host")
+ host[:port] = get_option("rabbitmq.pool.#{poolnum}.port", 6163).to_i
+ host[:login] = get_env_or_option("STOMP_USER", "rabbitmq.pool.#{poolnum}.user")
+ host[:passcode] = get_env_or_option("STOMP_PASSWORD", "rabbitmq.pool.#{poolnum}.password")
+ host[:ssl] = get_bool_option("rabbitmq.pool.#{poolnum}.ssl", false)
+
+ host[:ssl] = ssl_parameters(poolnum, get_bool_option("rabbitmq.pool.#{poolnum}.ssl.fallback", false)) if host[:ssl]
+
+ Log.debug("Adding #{host[:host]}:#{host[:port]} to the connection pool")
+ hosts << host
+ end
+
+ raise "No hosts found for the RabbitMQ connection pool" if hosts.size == 0
+
+ connection = {:hosts => hosts}
+
+ # Various STOMP gem options, defaults here matches defaults for 1.1.6 the meaning of
+ # these can be guessed, the documentation isn't clear
+ connection[:initial_reconnect_delay] = Float(get_option("rabbitmq.initial_reconnect_delay", 0.01))
+ connection[:max_reconnect_delay] = Float(get_option("rabbitmq.max_reconnect_delay", 30.0))
+ connection[:use_exponential_back_off] = get_bool_option("rabbitmq.use_exponential_back_off", true)
+ connection[:back_off_multiplier] = Integer(get_option("rabbitmq.back_off_multiplier", 2))
+ connection[:max_reconnect_attempts] = Integer(get_option("rabbitmq.max_reconnect_attempts", 0))
+ connection[:randomize] = get_bool_option("rabbitmq.randomize", false)
+ connection[:backup] = get_bool_option("rabbitmq.backup", false)
+ connection[:timeout] = Integer(get_option("rabbitmq.timeout", -1))
+ connection[:connect_timeout] = Integer(get_option("rabbitmq.connect_timeout", 30))
+ connection[:reliable] = true
+ connection[:vhost] = get_option("rabbitmq.vhost", "/")
+
+ connection[:logger] = EventLogger.new
+
+ @connection = connector.new(connection)
+ rescue Exception => e
+ raise("Could not connect to RabbitMQ Server: #{e}")
+ end
+ end
+
+ # Sets the SSL paramaters for a specific connection
+ def ssl_parameters(poolnum, fallback)
+ params = {:cert_file => get_option("rabbitmq.pool.#{poolnum}.ssl.cert", false),
+ :key_file => get_option("rabbitmq.pool.#{poolnum}.ssl.key", false),
+ :ts_files => get_option("rabbitmq.pool.#{poolnum}.ssl.ca", false)}
+
+ raise "cert, key and ca has to be supplied for verified SSL mode" unless params[:cert_file] && params[:key_file] && params[:ts_files]
+
+ raise "Cannot find certificate file #{params[:cert_file]}" unless File.exist?(params[:cert_file])
+ raise "Cannot find key file #{params[:key_file]}" unless File.exist?(params[:key_file])
+
+ params[:ts_files].split(",").each do |ca|
+ raise "Cannot find CA file #{ca}" unless File.exist?(ca)
+ end
+
+ begin
+ Stomp::SSLParams.new(params)
+ rescue NameError
+ raise "Stomp gem >= 1.2.2 is needed"
+ end
+
+ rescue Exception => e
+ if fallback
+ Log.warn("Failed to set full SSL verified mode, falling back to unverified: #{e.class}: #{e}")
+ return true
+ else
+ Log.error("Failed to set full SSL verified mode: #{e.class}: #{e}")
+ raise(e)
+ end
+ end
+
+ # Receives a message from the RabbitMQ connection
+ def receive
+ Log.debug("Waiting for a message from RabbitMQ")
+
+ # When the Stomp library > 1.2.0 is mid reconnecting due to its reliable connection
+ # handling it sets the connection to closed. If we happen to be receiving at just
+ # that time we will get an exception warning about the closed connection so handling
+ # that here with a sleep and a retry.
+ begin
+ msg = @connection.receive
+ rescue ::Stomp::Error::NoCurrentConnection
+ sleep 1
+ retry
+ end
+
+ raise "Received a processing error from RabbitMQ: '%s'" % msg.body.chomp if msg.body =~ /Processing error/
+
+ Message.new(msg.body, msg, :base64 => @base64, :headers => msg.headers)
+ end
+
+ # Sends a message to the RabbitMQ connection
+ def publish(msg)
+ msg.base64_encode! if @base64
+
+ if msg.type == :direct_request
+ msg.discovered_hosts.each do |node|
+ target = target_for(msg, node)
+
+ Log.debug("Sending a direct message to RabbitMQ target '#{target[:name]}' with headers '#{target[:headers].inspect}'")
+
+ @connection.publish(target[:name], msg.payload, target[:headers])
+ end
+ else
+ target = target_for(msg)
+
+ Log.debug("Sending a broadcast message to RabbitMQ target '#{target[:name]}' with headers '#{target[:headers].inspect}'")
+
+ @connection.publish(target[:name], msg.payload, target[:headers])
+ end
+ end
+
+ def target_for(msg, node=nil)
+ if msg.type == :reply
+ target = {:name => msg.request.headers["reply-to"], :headers => {}, :id => ""}
+
+ elsif [:request, :direct_request].include?(msg.type)
+ target = make_target(msg.agent, msg.type, msg.collective, node)
+
+ else
+ raise "Don't now how to create a target for message type #{msg.type}"
+
+ end
+
+ return target
+ end
+
+ def make_target(agent, type, collective, node=nil)
+ raise("Unknown target type #{type}") unless [:directed, :broadcast, :reply, :request, :direct_request].include?(type)
+ raise("Unknown collective '#{collective}' known collectives are '#{@config.collectives.join ', '}'") unless @config.collectives.include?(collective)
+
+ target = {:name => "", :headers => {}, :id => nil}
+
+ case type
+ when :reply # receiving replies on a temp queue
+ target[:name] = "/temp-queue/mcollective_reply_%s" % agent
+ target[:id] = "mcollective_%s_replies" % agent
+
+ when :broadcast, :request # publishing a request to all nodes with an agent
+ target[:name] = "/exchange/%s_broadcast/%s" % [collective, agent]
+ target[:headers]["reply-to"] = "/temp-queue/mcollective_reply_%s" % agent
+ target[:id] = "%s_broadcast_%s" % [collective, agent]
+
+ when :direct_request # a request to a specific node
+ raise "Directed requests need to have a node identity" unless node
+
+ target[:name] = "/exchange/%s_directed/%s" % [ collective, node]
+ target[:headers]["reply-to"] = "/temp-queue/mcollective_reply_%s" % agent
+
+ when :directed # subscribing to directed messages
+ target[:name] = "/exchange/%s_directed/%s" % [ collective, @config.identity ]
+ target[:id] = "%s_directed_to_identity" % @config.identity
+ end
+
+ target
+ end
+
+ # Subscribe to a topic or queue
+ def subscribe(agent, type, collective)
+ return if type == :reply
+
+ source = make_target(agent, type, collective)
+
+ unless @subscriptions.include?(source[:id])
+ Log.debug("Subscribing to #{source[:name]} with headers #{source[:headers].inspect.chomp}")
+ @connection.subscribe(source[:name], source[:headers], source[:id])
+ @subscriptions << source[:id]
+ end
+ rescue ::Stomp::Error::DuplicateSubscription
+ Log.error("Received subscription request for #{source.inspect.chomp} but already had a matching subscription, ignoring")
+ end
+
+ # Subscribe to a topic or queue
+ def unsubscribe(agent, type, collective)
+ return if type == :reply
+
+ source = make_target(agent, type, collective)
+
+ Log.debug("Unsubscribing from #{source[:name]}")
+ @connection.unsubscribe(source[:name], source[:headers], source[:id])
+ @subscriptions.delete(source[:id])
+ end
+
+ # Disconnects from the RabbitMQ connection
+ def disconnect
+ Log.debug("Disconnecting from RabbitMQ")
+ @connection.disconnect
+ end
+
+ # looks in the environment first then in the config file
+ # for a specific option, accepts an optional default.
+ #
+ # raises an exception when it cant find a value anywhere
+ def get_env_or_option(env, opt, default=nil)
+ return ENV[env] if ENV.include?(env)
+ return @config.pluginconf[opt] if @config.pluginconf.include?(opt)
+ return default if default
+
+ raise("No #{env} environment or plugin.#{opt} configuration option given")
+ end
+
+ # looks for a config option, accepts an optional default
+ #
+ # raises an exception when it cant find a value anywhere
+ def get_option(opt, default=nil)
+ return @config.pluginconf[opt] if @config.pluginconf.include?(opt)
+ return default unless default.nil?
+
+ raise("No plugin.#{opt} configuration option given")
+ end
+
+ # gets a boolean option from the config, supports y/n/true/false/1/0
+ def get_bool_option(opt, default)
+ return default unless @config.pluginconf.include?(opt)
+
+ val = @config.pluginconf[opt]
+
+ if val =~ /^1|yes|true/
+ return true
+ elsif val =~ /^0|no|false/
+ return false
+ else
+ return default
+ end
+ end
+ end
+ end
+end
+
+# vi:tabstop=4:expandtab:ai
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