zfs snapshots?! awe yis!

now I just need a straight forward way to `virt-restore` ...

	modified:   .gitignore
	modified:   virt-back

.gitignore

@@ -1,2 +1,9 @@
 venv
 virt_back.egg-info
+
+*.tar
+*.tar.gz
+
+*.tar.*
+*.tar.gz.*
+*.gz.*

virt-back

@@ -22,7 +22,7 @@ Use the Domfetcher class to aquire lists of dom objects."""
 import libvirt
 import tarfile
 import syslog
-from re import findall
+import re
 from time import sleep
 from datetime import date
 from sys import exit
@@ -31,6 +31,8 @@ from os import path
 from os import remove
 from shutil import move, copy2
 
+import subprocess
+
 try:
     from operator import methodcaller
 except ImportError:
@@ -118,10 +120,11 @@ def backup(doms):
 
         xml = dom.XMLDesc(0)
         xmlfile = path.join(options.backpath, dom.name() + ".xml")
-        f = open(xmlfile, "w")
-        f.write(xml)
-        f.close()
-        disklist = findall("<source file='(.*)'/>\n", xml)
+        with open(xmlfile, "w") as f:
+            f.write(xml)
+
+        # Updated regular expression to match file= and dev= within <disk> elements
+        disklist = re.findall(r"<disk.*?<source (?:file|dev)='(.*?)'.*?</disk>", xml, re.DOTALL)
 
         logit("backup", "invoking backup for " + dom.name())
 
@@ -132,14 +135,55 @@ def backup(doms):
                 )
                 continue
 
-            disk_file = disk_source.split("/")[-1]
-            disk_dest = path.join(options.backpath, disk_file)
+            if is_zfs_dataset(disk_source):
+                # Handle ZFS dataset
+                zfs_dataset = disk_source[len('/dev/zvol/'):] if disk_source.startswith('/dev/zvol/') else disk_source
+                zfs_snapshot_base = f"{zfs_dataset}@backup-{TODAY}"
+                zfs_snapshot = zfs_snapshot_base
+                suffix = 1
 
-            logit(
-                "backup",
-                "copying %s to %s for %s" % (disk_source, disk_dest, dom.name()),
-            )
-            copy2(disk_source, disk_dest)
+                # Increment snapshot name until an available name is found
+                while subprocess.run(["zfs", "list", zfs_snapshot], stdout=subprocess.PIPE, stderr=subprocess.PIPE).returncode == 0:
+                    zfs_snapshot = f"{zfs_snapshot_base}-{suffix}"
+                    suffix += 1
+
+                zfs_file = path.join(options.backpath, f"{dom.name()}-{TODAY}.zfs")
+                if not options.nogzip:
+                    zfs_file += ".gz"
+
+                # Create ZFS snapshot
+                logit("backup", f"creating ZFS snapshot {zfs_snapshot} for {dom.name()}")
+                try:
+                    subprocess.run(["zfs", "snapshot", zfs_snapshot], check=True)
+                except subprocess.CalledProcessError as e:
+                    logit("error", f"Failed to create ZFS snapshot {zfs_snapshot}: {e}")
+                    continue
+
+                # Send ZFS snapshot to file with optional compression
+                logit("backup", f"sending ZFS snapshot {zfs_snapshot} to {zfs_file} for {dom.name()}")
+                try:
+                    with open(zfs_file, "wb") as f:
+                        if options.nogzip:
+                            subprocess.run(["zfs", "send", zfs_snapshot], stdout=f, check=True)
+                        else:
+                            send_proc = subprocess.Popen(["zfs", "send", zfs_snapshot], stdout=subprocess.PIPE)
+                            gzip_proc = subprocess.Popen(["gzip"], stdin=send_proc.stdout, stdout=f)
+                            send_proc.stdout.close()  # Allow send_proc to receive a SIGPIPE if gzip_proc exits
+                            gzip_proc.communicate()
+                except subprocess.CalledProcessError as e:
+                    logit("error", f"Failed to send ZFS snapshot {zfs_snapshot}: {e}")
+                    continue
+            else:
+                # Handle QCOW2 or other file-based disk
+                logit("backup", f"{disk_source} is not a ZFS dataset")
+                disk_file = disk_source.split("/")[-1]
+                disk_dest = path.join(options.backpath, disk_file)
+
+                logit(
+                    "backup",
+                    "copying %s to %s for %s" % (disk_source, disk_dest, dom.name()),
+                )
+                copy2(disk_source, disk_dest)
 
         if recreate:  # if true, start guest after backup
             create([dom])  # start dom
@@ -169,17 +213,47 @@ def backup(doms):
             if disk_source.endswith(".iso"):
                 continue
 
-            disk_file = disk_source.split("/")[-1]
-            disk_dest = path.join(options.backpath, disk_file)
-            logit("backup", "archiving %s for %s" % (disk_dest, dom.name()))
-            tar.add(disk_dest)  # add img to tar
-            remove(disk_dest)  # cleanup tmp files
+            if is_zfs_dataset(disk_source):
+                zfs_file = path.join(options.backpath, f"{dom.name()}-{TODAY}.zfs")
+                if not options.nogzip:
+                    zfs_file += ".gz"
+                if path.isfile(zfs_file):
+                    logit("backup", "archiving %s for %s" % (zfs_file, dom.name()))
+                    tar.add(zfs_file)  # add zfs snapshot to tar
+                    remove(zfs_file)  # cleanup tmp files
+                else:
+                    logit("error", f"ZFS snapshot file {zfs_file} not found for {dom.name()}")
+            else:
+                disk_file = disk_source.split("/")[-1]
+                disk_dest = path.join(options.backpath, disk_file)
+                logit("backup", "archiving %s for %s" % (disk_dest, dom.name()))
+                tar.add(disk_dest)  # add img to tar
+                remove(disk_dest)  # cleanup tmp files
 
         tar.close()
 
         logit("backup", "finished backup for " + dom.name())
 
 
+def is_zfs_dataset(disk_source):
+    """Check if the disk source is a ZFS dataset"""
+    logit("backup", f"checking if {disk_source} is a ZFS dataset")
+    try:
+        # Extract the ZFS dataset name from the device path
+        if disk_source.startswith('/dev/zvol/'):
+            zfs_dataset = disk_source[len('/dev/zvol/'):]
+        else:
+            zfs_dataset = disk_source
+
+        result = subprocess.run(["zfs", "list", zfs_dataset], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        is_zfs = result.returncode == 0
+        logit("backup", f"{zfs_dataset} is {'a' if is_zfs else 'not a'} ZFS dataset")
+        return is_zfs
+    except Exception as e:
+        logit("error", f"Error checking ZFS dataset: {e}")
+        return False
+
+
 def shutdown(doms, wait=180):
     """Accept a list of dom objects, attempt to shutdown the active ones"""
     # get all running guests from list and invoke shutdown