Custom properties in VMware vRealize Automation (vRA) provide us with the ability to set data on vRA objects and to change configurations that affect the behaviour of objects in vRA. For example, when set on a vSphere Virtual Machine component contained in a composite blueprint in vRA 7, the property "VirtualMachine.Admin.ThinProvision" results in the virtual machine deployed with thin provisioned disks in vSphere. The "VirtualMachine.Admin.ThinProvision" property is a custom property that the out of the box vSphere provisioning workflow uses when set, and we do not have to do anything other than specifying a "true" value for the property to have an effect on the resulting virtual machine. VMware has developed the built-in workflows to make use of custom properties such as "VirtualMachine.Admin.ThinProvision" when they are specified on various components. These properties are documented in the "Custom Properties Reference" documentation provided with vRA 6 and 7.
Custom properties that ship out of the box with vRA, however, are only a small part of where the concept of custom properties can be used to extend the capabilities of your automation solution. Just as the built-in workflows make use of custom properties, so can your workflows take advantage of custom properties that you define using vRealize Orchestrator (vRO).
I have been dabbling in the world of vRO plugin development. Yes, I know, vRO is a product that doesn't get much love from the VMware community, and I do not think that is fair. People seem to have decided that the product is too complicated and where possible would rather write a PowerCLI script to automate things. The truth is, that when you take a little bit of time to look at vRO, you will find that it is not that complicated to develop vRO workflows and the possibilities are endless. I know, so I'm telling people that vRO isn't that complicated in a blog post which is targeted at myself for when I run into this issue in the future! So, if you are finding workflow development too complicated a task, this post is not for you, as I doubt you will be interested in plug-in development.