Ceph: Making Rados Gateway (RGW) available in Ceph UI after it has been deployed.

After deploying a Rados Gateway, (RGW), it may not be available in the Ceph UI.

Attempting to access the RGW (Cluster --> Object Gateway --> Daemons or Users or Bucket will throw up the following error message: "The Object Gateway Service is not configured"

The solution is to create a System User, which the UI can use to manage the RGW.

Here are the steps to create ...