VMWare and Serial Numbers

[tony_fugere]

Client came to me with a need to modify Discovery. All of their ESX Servers had a VMWare serial number (e.g. 12345c1c-1234-123a-123b-b1c23f4c5678). They want the actual server's hardware manufacturer serial number instead. SSH and SNMP were not an option. So, we did some digging on "The Google" and came across a PowerShell script that leverages the VMWare PowerCLI and CIM to extract the hardware serial number. Credit for that goes to RvdNieuwendijk on http://communities.vmware.com/message/1767984.

First, we have to setup the MID server a bit differently. The MID needs:

• VMWare vSphere PowerCLI installed
• A custom PowerShell Module created

Custom PowerShell Module

The probe uses this. In this case, C:\Service-now\agent\lib\vCenterConnect.psm1 is being used. This is important because it stores (in clear text) the password used to log onto the vCenter host. I know, I know, some of you are cringing right now. We figured that it is better to store it on the MID in a "secure" location instead of trying to pass it over the Internet in the probe parameter. We're still looking for a solution around that to keep it encrypted or more secure, but this met our needs for now. You'll see the use of "vCenterConnect -server $computer > $null" in the probe parameter which logs you into the vCenter to perform the rest of the functions.

C:\Service-now\agent\lib\vCenterConnect.psm1

function vCenterConnect([string]$server) {
connect-viserver -server $server -user USERNAME -Password PASSWORD
}
Export-ModuleMember vCenterConnect

---

Probe

Be sure to add this probe to the Triggers Probe list on the VMWare vCenter probe.

Name: VMWare Serial Number

Probe Type: Probe

ECC Queue Topic: Powershell

ECC Queue Name: VmWare Serial Number

Used by Discovery: true



Probe Parameter:

Name: VMWareSerial.ps1

Set-ExecutionPolicy Unrestricted
Add-PSSnapin VMware.VimAutomation.Core
Import-Module "C:\Service-now\agent\lib\vCenterConnect.psm1"

function Get-VMHostWSManInstance {
    param (
    [Parameter(Mandatory=$TRUE,HelpMessage="VMHosts to probe")]
    [VMware.VimAutomation.ViCore.Impl.V1.Inventory.VMHostImpl[]]
    $VMHost,

    [Parameter(Mandatory=$TRUE,HelpMessage="Class Name")]
    [string]
    $class,

    [switch]
    $ignoreCertFailures,

    [System.Management.Automation.PSCredential]
    $credential=$null
    )

    $omcBase = "http://schema.omc-project.org/wbem/wscim/1/cim-schema/2/"
    $dmtfBase = "http://schemas.dmtf.org/wbem/wscim/1/cim-schema/2/"
    $vmwareBase = "http://schemas.vmware.com/wbem/wscim/1/cim-schema/2/"

    if ($ignoreCertFailures) {
        $option = New-WSManSessionOption -SkipCACheck -SkipCNCheck -SkipRevocationCheck
    } else {
        $option = New-WSManSessionOption
    }
    foreach ($H in $VMHost) {
        Try
        {
        if ($credential -eq $null) {
            $hView = $H | Get-View -property Value
            $ticket = $hView.AcquireCimServicesTicket()
            $password = convertto-securestring $ticket.SessionId -asplaintext -force
            $credential = new-object -typename System.Management.Automation.PSCredential -argumentlist $ticket.SessionId, $password
        }
        $uri = "https`://" + $h.Name + "/wsman"
        if ($class -cmatch "^CIM") {
            $baseUrl = $dmtfBase
        } elseif ($class -cmatch "^OMC") {
            $baseUrl = $omcBase
        } elseif ($class -cmatch "^VMware") {
            $baseUrl = $vmwareBase
        } else {
            throw "Unrecognized class"
        }
       Get-WSManInstance -Authentication basic -ConnectionURI $uri -Credential $credential -Enumerate -Port 443 -UseSSL -SessionOption $option -ResourceURI "$baseUrl/$class"
       }
       Catch [system.exception]
       {
       }
    }
}

vCenterConnect -server $computer > $null

Get-VMHost | ForEach-Object {
  $VMHost = $_
  $PhysicalPackage = Get-VMHostWSManInstance -VMHost $_ -class CIM_PhysicalPackage -ignoreCertFailures | Where-Object {$_.ElementName -eq "Chassis"}
  $Report = "" | Select-Object -Property VMHost,SerialNumber
  $Report.VMHost = $VMHost.Name
  $Report.SerialNumber = $PhysicalPackage.SerialNumber
  $Report
}

---

Sensor:

Name: VMWare Serial Number (Sensor)

Reacts to Probe: VMWare Serial Number

Sensor Type: Sensor

Sensor type: Javascript

Active: true (obviously)
Description: Get actual server hardware serial numbers

Script:

new DiscoverySensor({
  process: function(result) {
    var foundStart = false;
    var lines = result.output.toString().split('\n');
    for(var i = 0, len = lines.length; i < len; i++) {
      var line = lines;
      if(/^VMHost +SerialNumber$/.test(line)) {
        foundStart = true;
      }
      if(foundStart && /^[a-z0-9]/.test(line)) {
        var parts = line.replace(/ +/, ' ').split(' ');
        var server = parts[0];
        var serial = parts[1];
        var computer = new GlideRecord('cmdb_ci_esx_server');
        server = server.substring(0, server.indexOf('.'));
        computer.addEncodedQuery('nameSTARTSWITH' + server);
        computer.query();
        if(computer.next()) {
          computer.serial_number = serial;
          computer.update();
        }
      }
    }
  },

  type: "DiscoverySensor"

 });

[mdillmann]

Hi Tony,

really good stuff. I am working on a PoV where we need to read out Tags assigned to a VM via a PowerCLI powershell probe.

Did you ever find out how to make the credentials-piece more secure or how to access the ServiceNow discovery crendtials table from a Powershell probe ?

Thanks,

-Markus

[tony_fugere]

Markus,

Unfortunately, I have not worked on or touched this one since I posted it. A quick Google search shows that there should be a way to accomplish a more secure credential storage.

VMware KB: Creating a VMware credential store file for third party plugins

New-VICredentialStoreItem

Tinker with those two and see if you can one-up my solution!