The vSphere API is an extensively rich interface for being able to extract all sorts of useful information about your vSphere infrastructure. One useful trick that may come in handy for those requiring to perform operations directly against the vCenter Server guestOS itself is to figure out whether you are connecting to a Windows vCenter Server or the vCenter Server Appliance (VCSA)? Lets say you wish to automate the deployment of the recently released VSAN 6.0 Health Check Plugin and the process to install the plugin will differ between Windows vCenter Server and the VCSA, so it would be ideal if you can easily distinguish between the two
A simplistic solution would be to quickly test for something that would exist in either Windows or Linux, but what if you wanted to perform these operations using the vSphere API and the Guest Operations API to execute the commands within the guests? Well, luckily the vSphere API actually provides this information when connecting to a vCenter Server API endpoint and you can tell if you are connecting to a Windows vCenter Server or the VCSA.
To determine the guestOS type for the vCenter Server you are connecting to, there is a property called osType which you can query when you first connect. Below is a quick PowerCLI snippet for accessing this property, you can also use a variety of other vSphere SDKs to extract this property.
$server = Connect-VIServer -Server reflex.primp-industries.com
Disconnect-VIServer -Server $server -Confirm:$false
The osType property for the VCSA is linux-x64