Automation – Page 163

How to automate vSphere MOB operations using PowerShell?

07.13.2016 by William Lam // 5 Comments

A couple of weeks back I was investigating something that involved the use of the vSphere Managed Object Browser (MOB) and I needed to automate a particular operation. For those of you not familiar with the vSphere MOB, it is a UI debugging tool that allows you to visualize and invoke vSphere APIs using just a web browser. The vSphere MOB is available on both vCenter Server and ESXi and uses the underlying vSphere API. Outside of learning about the vSphere APIs and potentially for troubleshooting purposes, there really is no good reason to be directly interacting with the vSphere MOB on a regular basis. Customers can use any one of the many vSphere SDK/CLIs to easily automate and interact with the vSphere API.

Having said that, there may be cases where you might want to invoke a specific operation using the vSphere MOB, such as private API for example. Obviously, using any private/internal APIs is not officially supported by VMware and their use will be at your own risk. Nonetheless, I had a specific operation that I needed to call from the vSphere MOB and wanted to do so using PowerShell. Several years back I had demonstrated how you could invoke the vSphere MOB using Python but I could not find any PowerShell examples that actually worked. I figured this would be a good learning opportunity for myself and probably something I or others could benefit in the future.

To provide a concrete example, I will be invoking a supported vSphere API called the QueryOptions which is used for accessing either a vCenter Server or ESXi Advanced Settings. For our example, I will be connecting to the vCenter Server's MOB and will be querying for a specific vCenter Server Advanced Setting. If we were to do this manually in the vSphere MOB, we would first open a web browser and login to the following URL: https://[VC-SERVER]/mob/?moid=VpxSettings&method=queryView

If you wanted to see all advanced settings, you would leave the "name" parameter blank. For our example, we will query for the VirtualCenter.InstanceName property as shown in the screenshot above and then click on the "Invoke Method" to execute the vSphere API operation. If successful, it should display the results which in our case is the IP Address of my vCenter Server. Pretty straight forward vSphere MOB example. OK, onto automating this from PowerShell. I have created a sample PowerShell script called automate-vsphere-mob.ps1 which you will need to edit and provide your vCenter Server Hostname/IP Address and the vCenter Server credentials (can be read-only) since we are not performing any write operations.

Here are some more specific details on what is happening in the script for those interested:

Authenticate to the vSphere MOB URL that you wish to invoke using an HTTP GET operation and storing the session into a variable named vmware (Line 28-29)
Extract the hidden vmware-session-nonce property used to prevent Cross-Site Request Forgery (CSRF) (Line 31-40)
Create the body request which must include the vmware-session-nounce property along with the vSphere API payload (Line 42-45)
Invoke the actual vSphere API call using an HTTP POST along with the existing session from Step 1 and body payload
Process the results (this will be specific to API call) and profit! (Line 50-59)

If you now run the script, you will see that the result is exactly what we saw from interactively using the vSphere MOB. Hopefully this will be useful for anyone who may have a need to automate against the vSphere MOB. For those curious on what I was investigating with the vSphere MOB, stay tuned for more details 🙂

How to audit vSphere Standalone VMRC or HTML5 VMRC connections?

07.11.2016 by William Lam // Leave a Comment

An interesting question that came in last week from one of our TAMs was how to identify and audit Virtual Machine Remote Console (VMRC) logins from vSphere? The TAM was specifically interested in being able to correlate that a particular user had logged into the VMRC of a VM during a specific period of time. Luckily, this is easily retrievable through vCenter Servers's Event sub-system that stores information about everything that happens in your vSphere environment. The Events can be accessed using either the vSphere Web Client shown below or programmatically using the vSphere API which the UI is built on top of.

You can obviously filter your search in the UI and focus on a particular VM, but often times there can be dozens if not hundreds of "Events" generated for a given VM. I personally prefer to leverage Automation when needing to look for a specific type of Event and more importantly, you can further process the results to either send out reports or hook into other third party systems. Now that we know, "where" to find our data, the next thing is identifying the type of Event that is generated for a VMRC connection.

As of vSphere 5.5 Update 2b, the VMRC in the vSphere Web Client can be accessed in one of two ways: The new HTML5 VMRC by clicking onto the VM screenshot thumbnail or the Standalone VMRC by clicking on the link directly beneath the VM screenshot.

Each VMRC connection method will generate a unique vCenter Server Event. For HTML5 VMRC connections, the Event is called VmAcquiredMksTicketEvent and for Standalone VMRC connections, the Event is called VmAcquiredTicketEvent. As I mentioned earlier, the vCenter Server Event sub-system can be accessed using the vSphere API and you can find the complete list of Events documented here. To demonstrate the use of this particular vSphere API, below is a PowerCLI example using the Get-VIEvent cmdlet. My fellow colleague Alan Renouf has actually blogged about working with Events using PowerCLI which I will be adapting one of his examples for our use case.

We first retrieve the VM that we are interested in by running the following command (specify the name of your VM):

$vm = Get-VM -Name "VCSA-60u2"

To retrieve HTML5 VMRC connections, run the following PowerCLI command:

Get-VIEvent -Entity $vm | Where { $_.Gettype().Name -eq "VmAcquiredMksTicketEvent"} | Select CreatedTime, UserName, FullFormattedMessage | ft -wrap -AutoSize

Here is an example of what the output would look like

To retrieve Standalone VMRC connections, run the following PowerCLI command:

Get-VIEvent -Entity $vm | Where { $_.Gettype().Name -eq "VmAcquiredTicketEvent"} | Select CreatedTime, UserName, UserAgent, FullFormattedMessage | ft -wrap -AutoSize

Here is an example of what the output would look like:

Quick Tip - How to quickly find the VM Display Name of your vCenter Server?

07.07.2016 by William Lam // 1 Comment

It is a pretty common practice for customers to use their vCenter Server to manage the underlying ESXi host which is also running the vCenter Server VM, sometimes referred to as a self managed vSphere Cluster. For organizations that have a strict naming convention which includes the VM display name as well as the OS hostname (FQDN), it is generally not too difficult to identify the actual VM that is running your vCenter Server.

However, for customers who may not have a VM display name that can easily be associated to their vCenter Server, it can be pretty difficult and time consuming to locate the vCenter Server VM for troubleshooting and/or updating purposes. Historically, this mapping and association has been left to our customers to document whether it is using a sticky, CMDB, vSphere Tags/Folders, etc. to be able to identify some of these more important VMs.

Luckily, there are some built-in mechanisms within vCenter Server itself that we can leverage to help us quickly identify the VM display name of our vCenter Server. Just this week while working on something, I actually came across another method which I think is even easier than the one I was familiar with.

Option #1 (harder) - When vCenter Server detects that it is in a self-managed configuration, it will automatically add a "System" metadata tag (not to be confused with vSphere Tags) to the actual vCenter Server VM. For vCenter Server, the "Tag" will have the value of SYSTEM/COM.VMWARE.VIM.VC which you can query on a VM using the vSphere API. Below is a PowerCLI example exercising the vSphere API:

$vm = Get-VM -name VCSA-60u2
(Get-View $vm).ExtensionData.Tag

The main issue here with this option is that because this information is at the VM level, you must first find the VM. This means, you would have to iterate through all of your VMs and seeing which has this particular property set with this value.

Option #2 (easier) - As mentioned earlier, I came across this new option by accident while browsing through the vCenter Server Advanced Settings. I noticed an interesting value for the following key: config.registry.key_VCVmId After a quick investigation, I found that vCenter Server also sets this Advanced Setting to the Managed Object Reference (MoRef) ID of the actual vCenter Server VM. This means, in one step, I know exactly which VM is my vCenter Server and I just need to convert the MoRef ID to a VM Object to then query the VM display name. How cool!?

The following PowerCLI example demonstrates how to extract the vCenter Server Advanced Setting, convert the MoRef ID to a VM Object which we can then query for its VM Display Name.

$vc_server = "192.168.1.51"
$vc_username = "*protected email*"
$vc_password = "VMware1!"

$server = Connect-VIServer -Server $vc_server -User $vc_username -Password $vc_password

# Retrieve the MoRef ID from following VC Advanced Setting
$vcMoRef = (Get-AdvancedSetting -Entity $server -Name config.registry.key_VCVmId).Value

# Construct VM from MoRef
$vm = New-Object VMware.Vim.ManagedObjectReference
$vm.Type = "VirtualMachine"
$vm.Value = $vcMoRef

Write-Host "The VM display name of this vCenter Server is"(Get-View $vm).name

Disconnect-viserver $server -confirm:$false

As you can see from the screenshot below, with just a few lines of code, we can quickly figure out our vCenter Server VM regardless if our inventory is 10 or 10,000 VMs. In fact, you can even output the exact ESXi host that is currently running the VM as well, but I will leave that as an exercise for the reader 🙂