So on an Amazon EC2 VM, you can do the following query:
http://169.254.169.254/latest/dynamic/instance-identity/document
This returns a document with information about how the VM fits into the cloud, such as the Instance ID and region name.
Note that because the URL starts with the bizarre APIPA address 169.254.169.254, you can't query this same URL from someplace outside the VM and get to the same place. It amounts to a privileged, secure query that can be done from the VM and from nowhere else.
Is there any mechanism at all like this in Azure to allow a VM to query a URL to get privileged, protected information about its place in the cloud?
Joseph