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Getting the Virtual System DNS Name

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The following C# and VBScript samples retrieve the DNS name of the virtual system.

To run this sample code, you must install the client integration services and the client operating system must be running.

using System;
using System.IO;
using System.Xml.XPath;
using System.Management;


// exchangeDataItem xml document sample instance
//
//<INSTANCE CLASSNAME="Msvm_KvpExchangeDataItem">
//      <PROPERTY NAME="Caption" PROPAGATED="true" TYPE="string"></PROPERTY>
//      <PROPERTY NAME="Data" TYPE="string">
//         <VALUE>AUTOBVT-4OVYXAB</VALUE>
//      </PROPERTY>
//      <PROPERTY NAME="Description" PROPAGATED="true" TYPE="string"></PROPERTY>
//      <PROPERTY NAME="ElementName" PROPAGATED="true" TYPE="string"></PROPERTY>
//      <PROPERTY NAME="Name" TYPE="string">
//         <VALUE>FullyQualifiedDomainName</VALUE>
//      </PROPERTY>
//      <PROPERTY NAME="Source" TYPE="uint16">
//          <VALUE>2</VALUE>
//      </PROPERTY>
//</INSTANCE>        



namespace HyperVSamples
{
    class GetVirtualMachineDNSName
    {
        static bool VMRunning(ManagementObject vm)
        {
            const int Enabled = 2;

            bool running = false;

            foreach (UInt16 operationStatus in (UInt16[])vm["OperationalStatus"])
            {
                if (operationStatus == Enabled)
                {
                    running = true;
                    break;
                }
            }

            return running;
        }

        static void GetVirtualSystemDNS(string vmName)
        {
            ManagementScope scope = new ManagementScope(@"root\virtualization", null);

            string query = String.Format("select * from Msvm_ComputerSystem where ElementName = '{0}'", vmName);

            ManagementObjectSearcher searcher = new ManagementObjectSearcher(scope, new ObjectQuery(query));

            ManagementObjectCollection vms = searcher.Get();

            foreach (ManagementObject vm in vms)
            {
                if (VMRunning(vm))
                {
                    ManagementObjectCollection kvpExchangeComponents = vm.GetRelated("Msvm_KvpExchangeComponent");
                    if (kvpExchangeComponents.Count != 1)
                    {
                        throw new Exception(String.Format("{0} instance of Msvm_KvpExchangeComponent was found", kvpExchangeComponents.Count));
                    }

                    foreach (ManagementObject kvpExchangeComponent in kvpExchangeComponents)
                    {
                        foreach (string exchangeDataItem in (string[])kvpExchangeComponent["GuestIntrinsicExchangeItems"])
                        {
                            XPathDocument xpathDoc = new XPathDocument(new StringReader(exchangeDataItem));
                            XPathNavigator navigator = xpathDoc.CreateNavigator();
                            navigator = navigator.SelectSingleNode("/INSTANCE/PROPERTY[@NAME='Name']/VALUE[child::text() = 'FullyQualifiedDomainName']");
                            if (navigator != null)
                            {
                                navigator = navigator.SelectSingleNode("/INSTANCE/PROPERTY[@NAME='Data']/VALUE/child::text()");
                                Console.WriteLine("Virtual machine {0} DNS name is: {1}", vmName, navigator.Value);
                                break;
                            }
                        }
                    }
                }
                else
                {
                    Console.WriteLine("Unable to retrieve virtual machine DNS name. VM {0} is not in running state", vmName);
                }
            }
        }

        static void Main(string[] args)
        {
            if (args != null &amp;&amp; args.Length != 1)
            {
                Console.WriteLine("Usage: GetVirtualMachineDNSName vmName");
                return;
            }
            GetVirtualSystemDNS(args[0]);
        }
    }
}

VB 
option explicit 

dim objWMIService
dim fileSystem


const Enabled = 2


Main()


'-----------------------------------------------------------------
' Main routine
'-----------------------------------------------------------------
Sub Main()


dim computer, objArgs, computerSystem, vmName

set fileSystem = Wscript.CreateObject(&quot;Scripting.FileSystemObject&quot;)

computer = &quot;.&quot;
set objWMIService = GetObject(&quot;winmgmts:\\&quot; &amp; computer &amp; &quot;\root\virtualization&quot;)

set objArgs = WScript.Arguments
if WScript.Arguments.Count = 1 then
   vmName= objArgs.Unnamed.Item(0)
else
   WScript.Echo &quot;usage: cscript GetVirtualMachineDNSName.vbs vmName&quot;
   WScript.Quit
end if

if GetVirtualSystemDNS(vmName) then
    WriteLog &quot;Done&quot;
    WScript.Quit(0)
else
    WriteLog &quot;GetVirtualMachineDNSName failed&quot;
    WScript.Quit(1)
end if



End Sub


'-----------------------------------------------------------------
' Check if virtual machine is running
'-----------------------------------------------------------------
Function VMRunning(computerSystem)
dim operationStatus


VMRunning = false

for each operationStatus in computerSystem.OperationalStatus
    if operationStatus = Enabled then
        VMRunning = true
        exit function
    end if
next



End Function


'-----------------------------------------------------------------
' GetVirtualSystemDNS
'
' exchangeDataItem xml document sample instance
'
' <INSTANCE CLASSNAME="Msvm_KvpExchangeDataItem">
'      <PROPERTY NAME="Caption" PROPAGATED="true" TYPE="string"></PROPERTY>
'      <PROPERTY NAME="Data" TYPE="string">
'         <VALUE>AUTOBVT-4OVYXAB</VALUE>
'      </PROPERTY>
'      <PROPERTY NAME="Description" PROPAGATED="true" TYPE="string"></PROPERTY>
'      <PROPERTY NAME="ElementName" PROPAGATED="true" TYPE="string"></PROPERTY>
'      <PROPERTY NAME="Name" TYPE="string">
'         <VALUE>FullyQualifiedDomainName</VALUE>
'      </PROPERTY>
'      <PROPERTY NAME="Source" TYPE="uint16">
'          <VALUE>2</VALUE>
'      </PROPERTY>
' </INSTANCE>

'-----------------------------------------------------------------
Function GetVirtualSystemDNS(vmName)
dim objXMLDoc, query , kvpExchangeComponents, kvpExchangeComponent, vm, vms
dim exchangeDataItem, xpath, node
GetVirtualSystemDNS = false
set objXMLDoc = CreateObject("Microsoft.XMLDOM")
objXMLDoc.async = False


query = Format1(&quot;select * from Msvm_ComputerSystem where ElementName = &#39;{0}&#39;&quot;, vmName)
set vms = objWMIService.ExecQuery(query)
for each vm in vms
    if VMRunning(vm) then
        query = Format1(&quot;ASSOCIATORS OF {{0}} WHERE resultClass = Msvm_KvpExchangeComponent&quot;, vm.Path_.Path)
        set kvpExchangeComponents = objWMIService.ExecQuery(query)
        if kvpExchangeComponents.Count &lt;&gt; 1 then
            WriteLog Format1(&quot;{0} instance of Msvm_KvpExchangeComponent was found&quot;, kvpExchangeComponents.Count)
            WScript.Quit(1)
        end if
        
        set kvpExchangeComponent = kvpExchangeComponents.ItemIndex(0)
        for each exchangeDataItem in kvpExchangeComponent.GuestIntrinsicExchangeItems
            objXMLDoc.loadXML(exchangeDataItem) 
            xpath = &quot;/INSTANCE/PROPERTY[@NAME=&#39;Name&#39;]/VALUE[child:text() = &#39;FullyQualifiedDomainName&#39;]&quot;
            set node = objXMLDoc.selectSingleNode(xpath) 
            if Not (node Is Nothing) then
                xpath = &quot;/INSTANCE/PROPERTY[@NAME=&#39;Data&#39;]/VALUE/child:text()&quot;
                set node = objXMLDoc.selectSingleNode(xpath) 
                WriteLog Format2(&quot;Virtual machine {0} DNS name is: {1}&quot;, vmName, node.Text)
            end if
        next
    else
        WriteLog Format1(&quot;Unable to retrieve virtual machine DNS name. VM {0} is not in running state&quot;, vmName)
        WScript.Quit(1)
    end if
next 

GetVirtualSystemDNS = true



End Function


'-----------------------------------------------------------------
' Create the console log files.
'-----------------------------------------------------------------
Sub WriteLog(line)
dim fileStream
set fileStream = fileSystem.OpenTextFile(".\GetVirtualSystemDNSName.log", 8, true)
WScript.Echo line
fileStream.WriteLine line
fileStream.Close


End Sub


'------------------------------------------------------------------------------
' The string formatting functions to avoid string concatenation.
'------------------------------------------------------------------------------
Function Format2(myString, arg0, arg1)
Format2 = Format1(myString, arg0)
Format2 = Replace(Format2, "{1}", arg1)
End Function


'------------------------------------------------------------------------------
' The string formatting functions to avoid string concatenation.
'------------------------------------------------------------------------------
Function Format1(myString, arg0)
Format1 = Replace(myString, "{0}", arg0)
End Function

Common Utilities for the Virtualization Samples

Msvm_ComputerSystem

Msvm_KvpExchangeComponent