Comment 11 for bug 2004632

Then you could either

1) Manually regenerate the key(s) as Huijuan Zhao suggested or
2) Remove the systemd/disable-sshd-keygen-if-cloud-init-active.conf file and restart the service or the system.

(2) is probably safe, after the first boot has run, as `cc_ssh` only runs on first boot. Thus, subsequent boots won't race with sshd-keygen.
Additionally, in your use case, you are generating a new set of keys which you are going to manually extract, so it does not matter if the keys are generated by cloud-init or sshd-keygen.