cloud-init “gotcha”

I was putting together a project using The Foreman to spin up and manage Amazon EC2 instances and ran into a problem. I could take an AMI and launch it, but I couldn’t ssh into it.

One of the major reasons why this was so was that cloud-init was silently failing and as a result, my ssh key wasn’t being installed.

The AMIs in question were built on top of Ubuntu 14.04LTS. The Foreman creates its own private access key to launch and control EC2 instances and it’s not accessible for general use. You have to supply your own private key if you want to login via ssh.

The recommended way to do that is to inject it via cloud-init. However, cloud-init wasn’t working right.

After a lot of experimentation, I discovered that the issue was in the attempt to also use cloud-init to set the simple hostname and fqdn of the newly-created host. Turns out that including the “host:” line like all the samples out on the Internet do causes the ENTIRE cloud-init file to be ignored. So in order to get my ssh key (AND hostname) injected, I just needed the “fqdn:” line.