On Thu, Aug 2, 2018 at 11:25 AM Scott Moser <[email protected]> wrote: > > > On Wed, Aug 1, 2018 at 12:09 PM Scott Moser <[email protected]> > > wrote: > > > > > > if we left it as null, it would not generate any keys. > > > We need it to generate keys. > > > > Why? isn't ssh-keygen service generating keys? > > That is the bug. We/centos/fedora *were* delegating generation of host keys > to ssh-keygen. That is problematic as ssh-keygen only generates new keys if > keys do not previously exist. That means that if the keys ever exist in an > image, every instance from that image will have the same host keys.
Hrm, it sort of feels like we should conflict with ssh-keygen; > > > > > You are correct in that it will generate the default key > > > types for cloud-init, which will not necessarily be the > > > same as those in ssh-keygen service. > > > > > > However, cloud-init will *remove* all ssh host keys that match > > > /etc/ssh/ssh_host_*key* > > > So we wont' have stale keys sitting around. > > > > Hrm, is the goal then to to have cloud-init wipe *all* keys even if it > > didn't > > generate them on new-instance? That would include any keys generated > > by the ssh-keygen service? And if so, is that OK for cloud-init to do? > > Deleting ssh host keys is somethign that cloud-init has *always* done on > first instance, so... yes it is OK for cloud-init to do that. It is possible > that someone has ssh host keys that they want to be used for multiple > instances.. and cloud-init would stop them. However, that is generally > against the design intent of ssh host keys, which are supposed to be per-host. > > > > > And from above, if ssh-keygen service is already creating keys, should > > cloud-init create keys as well? > > on a clean instance boot (no host keys at all): > * cloud-init.service will run 'Before=sshd-keygen.service' and will create > new host keys. > * ssh-keygen service will run and see it doesn't have anything to do. > > On second boot, cloud-init.service will not re-generate ssh host keys because > those are generated on a per-instance basis in cloud-init. > > On a *dirty* instance first boot (with previously generated ssh host keys) > * cloud-init.service will run 'Before=sshd-keygen.service' and will > * delete the old host keys > * generate host keys > * ssh-keygen.service will have nothing to do. Right, that seemed odd to me; why bother running it at all then if cloud-init is present and handling keygen? should we conflict? > > -- > https://code.launchpad.net/~smoser/cloud-init/+git/cloud-init/+merge/349359 > Your team cloud-init commiters is requested to review the proposed merge of > ~smoser/cloud-init:fix/1781094-ssh-deletekeys into cloud-init:master. > > _______________________________________________ > Mailing list: https://launchpad.net/~cloud-init-dev > Post to : [email protected] > Unsubscribe : https://launchpad.net/~cloud-init-dev > More help : https://help.launchpad.net/ListHelp -- https://code.launchpad.net/~smoser/cloud-init/+git/cloud-init/+merge/349359 Your team cloud-init commiters is requested to review the proposed merge of ~smoser/cloud-init:fix/1781094-ssh-deletekeys into cloud-init:master. _______________________________________________ Mailing list: https://launchpad.net/~cloud-init-dev Post to : [email protected] Unsubscribe : https://launchpad.net/~cloud-init-dev More help : https://help.launchpad.net/ListHelp
