Add ability to set operation ID for tracing

- add ability to pass in operation ID when connecting
- add ability to modify operation ID on connection

Fixes #105

lib/rbvmomi/trivial_soap.rb

@@ -8,7 +8,7 @@
 require 'pp'
 
 class RbVmomi::TrivialSoap
-  attr_accessor :debug, :cookie
+  attr_accessor :debug, :cookie, :operation_id
   attr_reader :http
 
   def initialize opts
@@ -17,6 +17,7 @@ def initialize opts
     return unless @opts[:host] # for testcases
     @debug = @opts[:debug]
     @cookie = @opts[:cookie]
+    @operation_id = @opts[:operation_id]
     @lock = Mutex.new
     @http = nil
     restart_http
@@ -64,11 +65,13 @@ def soap_envelope
     xsi = 'http://www.w3.org/2001/XMLSchema-instance'
     xml = Builder::XmlMarkup.new :indent => 0
     xml.tag!('env:Envelope', 'xmlns:xsd' => xsd, 'xmlns:env' => env, 'xmlns:xsi' => xsi) do
-      if @vcSessionCookie
+      if @vcSessionCookie || @operation_id
         xml.tag!('env:Header') do
-          xml.tag!('vcSessionCookie', @vcSessionCookie)
+          xml.tag!('vcSessionCookie', @vcSessionCookie) if @vcSessionCookie
+          xml.tag!('operationID', @operation_id) if @operation_id
         end
       end
+
       xml.tag!('env:Body') do
         yield xml if block_given?
       end

lib/rbvmomi/vim.rb

@@ -27,6 +27,7 @@ class VIM < Connection
   # @option opts [String]  :password Password.
   # @option opts [String]  :path (/sdk) SDK endpoint path.
   # @option opts [Boolean] :debug (false) If true, print SOAP traffic to stderr.
+  # @option opts [String]  :operation_id If set, use for operationID
   def self.connect opts
     fail unless opts.is_a? Hash
     fail "host option required" unless opts[:host]