Comment 3 for bug 1650677

None of my sysv/upstart jobs ever created host keys at boot time; I have specifically nacked that multiple times because the time you exactly shouldn't generate host keys is at boot when the system is low on entropy (there is academic research about how that particular idea leads to weak keys in the wild). Anything which you observed doing that in the past was outside of the openssh package, and either without my knowledge or over my objections.

Host keys should normally be created at installation time (e.g. when the image is installed on the device, if this is an image-based upgrade) instead, or at least at some point when sufficient entropy is likely to be available.