Add extra functions to rbvmomi as monkey patch

Instead of modifying vendorized files

src/vmm_mad/remotes/vcenter/vcenter_driver.rb

@@ -44,6 +44,70 @@ require 'openssl'
 require 'openssl'
 require 'VirtualMachineDriver'
 
+
+################################################################################
+# Monkey patch rbvmomi library with some extra functions
+################################################################################
+
+class RbVmomi::VIM::Datastore
+
+    # Download a file from this datastore.
+    # @param remote_path [String] Source path on the datastore.
+    # @param local_path [String] Destination path on the local machine.
+    # @return [void]
+    def download_to_stdout remote_path
+        url = "http#{_connection.http.use_ssl? ? 's' : ''}://#{_connection.http.address}:#{_connection.http.port}#{mkuripath(remote_path)}"
+
+        pid = spawn CURLBIN, "-k", '--noproxy', '*', '-f',
+                    "-b", _connection.cookie,
+                    url
+
+
+        Process.waitpid(pid, 0)
+        fail "download failed" unless $?.success?
+    end
+
+    def is_descriptor? remote_path
+        url = "http#{_connection.http.use_ssl? ? 's' : ''}://#{_connection.http.address}:#{_connection.http.port}#{mkuripath(remote_path)}"
+
+        rout, wout = IO.pipe
+
+        pid = spawn CURLBIN, "-I", "-k", '--noproxy', '*', '-f',
+                    "-b", _connection.cookie,
+                    url,
+                    :out => wout,
+                    :err => '/dev/null'
+
+        Process.waitpid(pid, 0)
+        fail "read image header failed" unless $?.success?
+
+        wout.close
+        size = rout.readlines.select{|l| l.start_with?("Content-Length")}[0].sub("Content-Length: ","")
+        rout.close
+        size.chomp.to_i < 4096   # If <4k, then is a descriptor
+    end
+
+    def get_text_file remote_path
+        url = "http#{_connection.http.use_ssl? ? 's' : ''}://#{_connection.http.address}:#{_connection.http.port}#{mkuripath(remote_path)}"
+
+        rout, wout = IO.pipe
+        pid = spawn CURLBIN, "-k", '--noproxy', '*', '-f',
+                    "-b", _connection.cookie,
+                    url,
+                    :out => wout,
+                    :err => '/dev/null'
+
+        Process.waitpid(pid, 0)
+        fail "get text file failed" unless $?.success?
+
+        wout.close
+        output = rout.readlines
+        rout.close
+        return output
+    end
+
+end
+
 module VCenterDriver
 
 ################################################################################