This is a very quick article covering how to get Orchestrator added into Cloud Assembly so that it can be used for extensibility. This may seem quite obvious to some people however there are a few gotchas!
Deploy an Orchestrator
In order to connect in an on-prem vRO instance to Cloud Assembly you first need to have deployed that vRO instance. The link provided in “Connections > Integrations > Add Integration > vRealize Orchestrator” allows you to pull down an OVA file hosted on Amazons content distribution network. This image is customised as it includes a plugin for CAS (Cloud Services plugin). Unfortunately when i was writing this article the OVA file that comes down was version 7.5.0 and Cloud Assembly now requires 7.6.0 following a recent update. When you try to add an incompatible vRO version to Cloud Assembly you get an error similar to this:

In the abscence of an updated hyperlink within Cloud Assembly (this is now fixed!) I installed a standalone 7.6.0 appliance and set it’s authentication provider to be an on-prem vCenter (you will need to set the authentication to either vRA or vSphere no matter how you deploy vRO).
The orchestrator instance needs the “VMware Cloud Services” plugin if you wish to use it to interact with VMware Cloud Automation Services so I retrospectively installed it just like any other vRO plugin. I was able to do this because I work for VMware and therefore have access to all the binaries. For anybody else who wants to use an existing vRO instance that is a supported vRO version, this would require a support call to be opened or being able to export the plugin off a vRO system that already had it.
Communications
Cloud Assembly can only talk to an on-prem vRO if there is a deployed cloud proxy appliance which can reach the vRO server. This can be the same proxy appliance as used to talk to an on-prem vCenter if one exists already.
The proxy appliance and the vRO server must be able to communicate with each other and resolve each other via DNS lookup if you are going to add vRO into Cloud Assembly via its hostname.
It goes without saying that the proxy appliance must also be able to reach the VMware URLs need for Cloud Assembly functionality. This can be verified by logging into the proxy appliance as root which will automatically run the status check script.

You can also kick this check off remotely by going to the “Connections > Cloud Proxies” screen, locating your collector and executing a status check.


Adding the Integration
Once all the pre-requisite steps have been completed the integration can be added as shown below. Note that port 8281 is required on the URL and that the hostname or IP address used in the URL should be resolvable/reachable by the cloud proxy server.

Once added, the vRO server will show up in the integrations list and will be data collected every 10 minutes.