Implement --utc switch to force UTC time (closes #155)

tests/test_zfsautobackup.py

@@ -892,7 +892,7 @@ test_target1/test_source2/fs2/sub@test-20101111000003
         r = shelltest("zfs snapshot test_source1@test")
 
         l=LogConsole(show_verbose=True, show_debug=False, color=False)
-        n=ZfsNode(snapshot_time_format="bla", hold_name="bla", logger=l)
+        n=ZfsNode(utc=False, snapshot_time_format="bla", hold_name="bla", logger=l)
         d=ZfsDataset(n,"test_source1@test")
 
         sp=d.send_pipe([], prev_snapshot=None, resume_token=None, show_progress=True, raw=False, send_pipes=[], send_properties=True, write_embedded=True, zfs_compressed=True)

tests/test_zfsnode.py

@@ -12,7 +12,7 @@ class TestZfsNode(unittest2.TestCase):
     def test_consistent_snapshot(self):
         logger = LogStub()
         description = "[Source]"
-        node = ZfsNode(snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
+        node = ZfsNode(utc=False, snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
 
         with self.subTest("first snapshot"):
             node.consistent_snapshot(node.selected_datasets(property_name="autobackup:test",exclude_paths=[], exclude_received=False, exclude_unchanged=False, min_change=200000), "test-20101111000001", 100000)
@@ -74,7 +74,7 @@ test_target1
     def test_consistent_snapshot_prepostcmds(self):
         logger = LogStub()
         description = "[Source]"
-        node = ZfsNode(snapshot_time_format="test", hold_name="test", logger=logger, description=description, debug_output=True)
+        node = ZfsNode(utc=False, snapshot_time_format="test", hold_name="test", logger=logger, description=description, debug_output=True)
 
         with self.subTest("Test if all cmds are executed correctly (no failures)"):
             with OutputIO() as buf:
@@ -137,7 +137,7 @@ test_target1
 
         logger = LogStub()
         description = "[Source]"
-        node = ZfsNode(snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
+        node = ZfsNode(utc=False, snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
         s = pformat(node.selected_datasets(property_name="autobackup:test", exclude_paths=[], exclude_received=False, exclude_unchanged=True, min_change=1))
         print(s)
 
@@ -150,7 +150,7 @@ test_target1
     def test_validcommand(self):
         logger = LogStub()
         description = "[Source]"
-        node = ZfsNode(snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
+        node = ZfsNode(utc=False, snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
 
         with self.subTest("test invalid option"):
             self.assertFalse(node.valid_command(["zfs", "send", "--invalid-option", "nonexisting"]))
@@ -160,7 +160,7 @@ test_target1
     def test_supportedsendoptions(self):
         logger = LogStub()
         description = "[Source]"
-        node = ZfsNode(snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
+        node = ZfsNode(utc=False, snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description)
         # -D propably always supported
         self.assertGreater(len(node.supported_send_options), 0)
 
@@ -168,7 +168,7 @@ test_target1
         logger = LogStub()
         description = "[Source]"
         # NOTE: this could hang via ssh if we dont close filehandles properly. (which was a previous bug)
-        node = ZfsNode(snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description, ssh_to='localhost')
+        node = ZfsNode(utc=False, snapshot_time_format="test-%Y%m%d%H%M%S", hold_name="zfs_autobackup:test", logger=logger, description=description, ssh_to='localhost')
         self.assertIsInstance(node.supported_recv_options, list)
 
 

zfs_autobackup/CliBase.py

@@ -80,6 +80,8 @@ class CliBase(object):
                             help='show zfs progress output. Enabled automaticly on ttys. (use --no-progress to disable)')
         group.add_argument('--no-progress', action='store_true',
                             help=argparse.SUPPRESS)  # needed to workaround a zfs recv -v bug
+        group.add_argument('--utc', action='store_true',
+                            help='Use UTC instead of local time when dealing with timestamps for both formatting and parsing. To snapshot in an ISO 8601 compliant time format you may for example specify --snapshot-format "%Y-%m-%dT%H:%M:%SZ". Changing this parameter after-the-fact (existing snapshots) will cause their timestamps to be interpreted as a different time than before.')
         group.add_argument('--version', action='store_true',
                             help='Show version.')
 
@@ -106,4 +108,4 @@ class CliBase(object):
 
     def set_title(self, title):
         self.log.verbose("")
-        self.log.verbose("#### " + title)
+        self.log.verbose("#### " + title)

zfs_autobackup/ZfsAuto.py

@@ -61,6 +61,7 @@ class ZfsAuto(CliBase):
         self.verbose("")
         self.verbose("Selecting dataset property : {}".format(self.property_name))
         self.verbose("Snapshot format            : {}".format(self.snapshot_time_format))
+        self.verbose("Timezone                   : {}".format("UTC" if args.utc else "Local"))
 
         return args
 

zfs_autobackup/ZfsAutobackup.py

@@ -1,6 +1,7 @@
 import time
 
 import argparse
+from datetime import datetime
 from signal import signal, SIGPIPE
 from .util import output_redir, sigpipe_handler
 
@@ -12,7 +13,6 @@ from .Thinner import Thinner
 from .ZfsDataset import ZfsDataset
 from .ZfsNode import ZfsNode
 from .ThinnerRule import ThinnerRule
-import os.path
 
 class ZfsAutobackup(ZfsAuto):
     """The main zfs-autobackup class. Start here, at run() :)"""
@@ -435,7 +435,8 @@ class ZfsAutobackup(ZfsAuto):
                 source_thinner = None
             else:
                 source_thinner = Thinner(self.args.keep_source)
-            source_node = ZfsNode(snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name, logger=self,
+            source_node = ZfsNode(utc=self.args.utc,
+                                  snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name, logger=self,
                                   ssh_config=self.args.ssh_config,
                                   ssh_to=self.args.ssh_source, readonly=self.args.test,
                                   debug_output=self.args.debug_output, description=description, thinner=source_thinner)
@@ -454,7 +455,8 @@ class ZfsAutobackup(ZfsAuto):
             ################# snapshotting
             if not self.args.no_snapshot:
                 self.set_title("Snapshotting")
-                snapshot_name = time.strftime(self.snapshot_time_format)
+                dt = datetime.utcnow() if self.args.utc else datetime.now()
+                snapshot_name = dt.strftime(self.snapshot_time_format)
                 source_node.consistent_snapshot(source_datasets, snapshot_name,
                                                 min_changed_bytes=self.args.min_change,
                                                 pre_snapshot_cmds=self.args.pre_snapshot_cmd,
@@ -471,7 +473,8 @@ class ZfsAutobackup(ZfsAuto):
                     target_thinner = None
                 else:
                     target_thinner = Thinner(self.args.keep_target)
-                target_node = ZfsNode(snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name,
+                target_node = ZfsNode(utc=self.args.utc,
+                                      snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name,
                                       logger=self, ssh_config=self.args.ssh_config,
                                       ssh_to=self.args.ssh_target,
                                       readonly=self.args.test, debug_output=self.args.debug_output,

zfs_autobackup/ZfsAutoverify.py

@@ -231,7 +231,8 @@ class ZfsAutoverify(ZfsAuto):
             self.set_title("Source settings")
 
             description = "[Source]"
-            source_node = ZfsNode(snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name, logger=self,
+            source_node = ZfsNode(utc=self.args.utc,
+                                  snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name, logger=self,
                                   ssh_config=self.args.ssh_config,
                                   ssh_to=self.args.ssh_source, readonly=self.args.test,
                                   debug_output=self.args.debug_output, description=description)
@@ -249,7 +250,8 @@ class ZfsAutoverify(ZfsAuto):
 
             # create target_node
             self.set_title("Target settings")
-            target_node = ZfsNode(snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name,
+            target_node = ZfsNode(utc=self.args.utc,
+                                  snapshot_time_format=self.snapshot_time_format, hold_name=self.hold_name,
                                   logger=self, ssh_config=self.args.ssh_config,
                                   ssh_to=self.args.ssh_target,
                                   readonly=self.args.test, debug_output=self.args.debug_output,

zfs_autobackup/ZfsCheck.py

@@ -18,7 +18,7 @@ class ZfsCheck(CliBase):
         # NOTE: common options argument parsing are in CliBase
         super(ZfsCheck, self).__init__(argv, print_arguments)
 
-        self.node = ZfsNode(self.log, readonly=self.args.test, debug_output=self.args.debug_output)
+        self.node = ZfsNode(self.log, utc=self.args.utc, readonly=self.args.test, debug_output=self.args.debug_output)
 
         self.block_hasher = BlockHasher(count=self.args.count, bs=self.args.block_size, skip=self.args.skip)
 

zfs_autobackup/ZfsDataset.py

@@ -1,4 +1,6 @@
 import re
+from datetime import datetime
+import sys
 import time
 
 from .CachedProperty import CachedProperty
@@ -375,9 +377,22 @@ class ZfsDataset:
         """get timestamp from snapshot name. Only works for our own snapshots
         with the correct format.
         """
-
-        time_secs = time.mktime(time.strptime(self.snapshot_name, self.zfs_node.snapshot_time_format))
-        return time_secs
+        dt = datetime.strptime(self.snapshot_name, self.zfs_node.snapshot_time_format)
+        if sys.version_info[0] >= 3:
+            from datetime import timezone
+            if self.zfs_node.utc:
+                dt = dt.replace(tzinfo=timezone.utc)
+            seconds = dt.timestamp()
+        else:
+            # python2 has no good functions to deal with UTC. Yet the unix timestamp
+            # must be in UTC to allow comparison against `time.time()` in on other parts
+            # of this project (e.g. Thinner.py). If we are handling UTC timestamps,
+            # we must adjust for that here.
+            if self.zfs_node.utc:
+                seconds = (dt - datetime(1970, 1, 1)).total_seconds()
+            else:
+                seconds = time.mktime(dt.timetuple())
+        return seconds
 
     def from_names(self, names):
         """convert a list of names to a list ZfsDatasets for this zfs_node

zfs_autobackup/ZfsNode.py

@@ -17,10 +17,11 @@ from .ExecuteNode import ExecuteError
 class ZfsNode(ExecuteNode):
     """a node that contains zfs datasets. implements global (systemwide/pool wide) zfs commands"""
 
-    def __init__(self, logger, snapshot_time_format="", hold_name="", ssh_config=None, ssh_to=None, readonly=False,
+    def __init__(self, logger, utc=False, snapshot_time_format="", hold_name="", ssh_config=None, ssh_to=None, readonly=False,
                  description="",
                  debug_output=False, thinner=None):
 
+        self.utc = utc
         self.snapshot_time_format = snapshot_time_format
         self.hold_name = hold_name