I am targeting the overall rancher user base here more than the Rancher Labs team.
Unfortunately due to policies, I am unable to use the stock Ubuntu image that rancher works beautifully (deploying on EC2 from within Rancher) with and must instead maintain an internal golden Debian Jessie image. I have been maintaining this AMI for awhile and updating it as needed, but now I need it to accept dynamic keypairs such as those generated by docker machine. I am fully willing to admit this is beyond the scope of my knowledge currently.
Based on what I have read, this is accomplished using CloudInit (somehow getting the keypair from the exposed API inside every AWS machine). However, I have been unable to find any solid documentation or examples of this outside of hardcoding public keys into the cloud config.
If anyone has any experience configuring AMIs to dynamically accept AWS variables please teach me your ways!