Even in a cloud world, sometimes you need to find a way to get inside your VM when SSH doesn’t work. Maybe your Ansible script broke the SSH configuration and you need to debug it, or you lost the key you used when creating the VM, or <insert random reason here>.
The good news is that OpenStack environments give you a connection to the VM console. However, CentOS 7 (and RHEL 7) images are a bit tricky when you want to boot in single user mode, as they request the root password, which we don’t have. There is a well documented procedure to boot using rd.break, but there are some little quirks to adapt it for OpenStack images. But fear not, I have summarized them in this post.