Port regenerate_ssh_host_key to a systemd service

stage2/01-sys-tweaks/01-run.sh

@@ -1,6 +1,6 @@
 #!/bin/bash -e
 
-install -m 755 files/regenerate_ssh_host_keys		${ROOTFS_DIR}/etc/init.d/
+install -m 644 files/regenerate_ssh_host_keys.service	${ROOTFS_DIR}/lib/systemd/system/
 install -m 755 files/apply_noobs_os_config		${ROOTFS_DIR}/etc/init.d/
 install -m 755 files/resize2fs_once			${ROOTFS_DIR}/etc/init.d/
 

stage2/01-sys-tweaks/files/regenerate_ssh_host_keys

@@ -1,36 +0,0 @@
-#!/bin/sh
-### BEGIN INIT INFO
-# Provides:          regenerate_ssh_host_keys
-# Required-Start:
-# Required-Stop:
-# Default-Start: 2
-# Default-Stop:
-# Short-Description: Regenerate ssh host keys
-# Description:
-### END INIT INFO
-
-. /lib/lsb/init-functions
-
-set -e
-
-case "$1" in
-  start)
-    log_daemon_msg "Regenerating ssh host keys"
-    nohup sh -c "if [ -e /dev/hwrng ]; then
-          dd if=/dev/hwrng of=/dev/urandom count=1 bs=4096
-      fi; \
-      yes | ssh-keygen -q -N '' -t dsa -f /etc/ssh/ssh_host_dsa_key && \
-      yes | ssh-keygen -q -N '' -t rsa -f /etc/ssh/ssh_host_rsa_key && \
-      yes | ssh-keygen -q -N '' -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key && \
-      yes | ssh-keygen -q -N '' -t ed25519 -f /etc/ssh/ssh_host_ed25519_key && \
-      sync && \
-      rm /etc/init.d/regenerate_ssh_host_keys && \
-      update-rc.d regenerate_ssh_host_keys remove && \
-      printf '\nfinished\n'" > /var/log/regen_ssh_keys.log 2>&1
-    log_end_msg $?
-    ;;
-  *)
-    echo "Usage: $0 start" >&2
-    exit 3
-    ;;
-esac

stage2/01-sys-tweaks/files/regenerate_ssh_host_keys.service

@@ -0,0 +1,11 @@
+[Unit]
+Description=Regenerate SSH host keys
+
+[Service]
+Type=oneshot
+ExecStartPre=/bin/sh -c "if [ -e /dev/hwrng ]; then dd if=/dev/hwrng of=/dev/urandom count=1 bs=4096; fi"
+ExecStart=/usr/bin/ssh-keygen -A
+ExecStartPost=/bin/rm /lib/systemd/system/regenerate_ssh_host_keys.service ; /usr/sbin/update-rc.d regenerate_ssh_host_keys remove
+
+[Install]
+WantedBy=multi-user.target