ssh: add sshd-keygen service for firstboot

Need to generate the host keys on first boot, otherwise ssh will fail

Author: bluca

mkosi.conf.d/20-debian/mkosi.extra/usr/lib/systemd/system/sshd-keygen.service

@@ -0,0 +1,15 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+[Unit]
+ConditionFirstBoot=yes
+ConditionPathIsReadWrite=/etc/ssh
+ConditionPathIsSymbolicLink=!/etc/ssh
+Before=ssh.service sshd.service [email protected]
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=ssh-keygen -A
+
+[Install]
+WantedBy=ssh.service sshd.service [email protected] ssh.socket sshd.socket

mkosi.extra/usr/lib/systemd/system-preset/10-particleos.preset

@@ -32,3 +32,4 @@ disable sshd.service
 disable ssh.service
 enable sshd.socket
 enable ssh.socket
+enable sshd-keygen.service