I'm spending a little time looking again at the problem I have with my instance not autojoining my cluster. @angrychimp had described using "register-container-instance" to do this manually. I'd still like to know why it isn't auto-joining, but I'm willing to at least try to do it manually. However, I'm having trouble with this, not with that command line, but getting the piece of information I need for it to work, being the "instance-identity-document". According to that, I plugged the public IP of my instance into the URL specified in the doc, but it never seems to return from this. The curl call just hangs.