added own service for creating overlays

rootfs-overlay/etc/systemd/system/local-fs-pre.target.wants/nimux-zfs-mount.service

@@ -0,0 +1 @@
+/usr/lib/systemd/system/nimux-zfs-mount.service

rootfs-overlay/usr/lib/nimux/nimux-early-mount.xsh

@@ -0,0 +1,23 @@
+#!/bin/xonsh --no-rc
+# Nimux Early Mount (xonsh)
+
+#mount /mnt
+print("mount /mnt")
+/bin/mount /mnt
+
+# mount root on future accesable place
+print("re-mount rootfs")
+/bin/mkdir -p /mnt/rootfs
+/bin/mount --bind / /mnt/rootfs
+/bin/mount --make-rprivate /mnt/rootfs/
+
+# import zpool
+print("import zpool")
+/sbin/zpool import nimux-zfs
+
+# overlay etc and home with a persistant zfs dataset
+print("overlay mount etc")
+/bin/unionfs -o cow,nonempty /mnt/rootfs.overlay/etc=RW:/mnt/rootfs/etc=RO /etc
+print("overlay mount home")
+/bin/unionfs -o cow,nonempty /mnt/rootfs.overlay/home=RW:/mnt/rootfs/home=RO /home
+

rootfs-overlay/usr/lib/systemd/system/nimux-zfs-mount.service

@@ -0,0 +1,23 @@
+[Unit]
+Description=Nimux early mount: ZFS import + overlay for /etc and /home
+DefaultDependencies=no
+After=systemd-udev-settle.service
+Wants=systemd-udev-settle.service
+Before=local-fs-pre.target local-fs.target
+Wants=local-fs-pre.target
+Conflicts=shutdown.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+Environment=XONSH_HISTORY_BACKEND=none
+Environment=XONSH_CACHE_DIR=/dev/null
+Environment=XONSH_DATA_DIR=/dev/null
+Environment=HOME=/tmp/xonsh-home
+ExecStart=/usr/lib/nimux/nimux-early-mount.xsh
+TimeoutStartSec=30s
+
+
+[Install]
+WantedBy=local-fs-pre.target
+