My experience agrees with the general tone of the article (although I didn't dig as deep into the code as OP). I implemented an OpenStack private cloud for test

My experience agrees with the general tone of the article (although I didn't dig as deep into the code as OP). I implemented an OpenStack private cloud for testing/QA purposes but never felt comfortable enough with it to migrate production (this was Icehouse, so pretty recent). It was too easy to break core functionality--for example, I literally never saw resizing an instance work properly. It does this crazy hack where under the hood it SCPs the VM image to another host and then tries to bring it up. It could have been a quirk of our installation but it would break every time. I saw similar breakage with Cinder operations where volumes would get "stuck" on VMs. Again, it could be a bad installation but it goes to show you how easy it is to break OpenStack if you aren't an expert in the codebase. My current thinking is that a container-centric (as opposed to VM-centric) infrastructure is the way to go--that way I can just throw CoreOS or whatever on the bare metal nodes and migrate containers as needed.