fix #84

Add support for pre- and post-snapshot scripts (#39)

.github/workflows/regression.yml

@@ -17,7 +17,7 @@ jobs:
 
 
       - name: Prepare
-        run: sudo apt update && sudo apt install zfsutils-linux && sudo -H pip3 install coverage unittest2 mock==3.0.5 coveralls
+        run: sudo apt update && sudo apt install zfsutils-linux lzop pigz zstd gzip xz-utils lz4 mbuffer && sudo -H pip3 install coverage unittest2 mock==3.0.5 coveralls
 
 
       - name: Regression test
@@ -39,7 +39,7 @@ jobs:
 
 
       - name: Prepare
-        run: sudo apt update && sudo apt install zfsutils-linux python3-setuptools && sudo -H pip3 install coverage unittest2 mock==3.0.5 coveralls
+        run: sudo apt update && sudo apt install zfsutils-linux python3-setuptools lzop pigz zstd gzip xz-utils liblz4-tool mbuffer && sudo -H pip3 install coverage unittest2 mock==3.0.5 coveralls
 
 
       - name: Regression test
@@ -64,7 +64,7 @@ jobs:
           python-version: '2.x'
 
       - name: Prepare
-        run: sudo apt update && sudo apt install zfsutils-linux python-setuptools && sudo -H pip install coverage unittest2 mock==3.0.5 coveralls colorama
+        run: sudo apt update && sudo apt install zfsutils-linux python-setuptools lzop pigz zstd gzip xz-utils liblz4-tool mbuffer && sudo -H pip install coverage unittest2 mock==3.0.5 coveralls colorama
 
       - name: Regression test
         run: sudo -E ./tests/run_tests

README.md

@@ -5,7 +5,7 @@
 
 ## Introduction
 
-This is a tool I wrote to make replicating ZFS datasets easy and reliable.
+ZFS-autobackup tries to be the most reliable and easiest to use tool, while having all the features.
 
 You can either use it as a **backup** tool, **replication** tool or **snapshot** tool.
 
@@ -13,12 +13,10 @@ You can select what to backup by setting a custom `ZFS property`. This makes it
 
 Other settings are just specified on the commandline: Simply setup and test your zfs-autobackup command and  fix all the issues you might encounter. When you're done you can just copy/paste your command to a cron or script.
 
-Since its using ZFS commands, you can see what its actually doing by specifying `--debug`. This also helps a lot if you run into some strange problem or error. You can just copy-paste the command that fails and play around with it on the commandline. (something I missed in other tools)
+Since its using ZFS commands, you can see what it's actually doing by specifying `--debug`. This also helps a lot if you run into some strange problem or error. You can just copy-paste the command that fails and play around with it on the commandline. (something I missed in other tools)
 
 An important feature thats missing from other tools is a reliable `--test` option: This allows you to see what zfs-autobackup will do and tune your parameters. It will do everything, except make changes to your system.
 
-zfs-autobackup tries to be the easiest to use backup tool for zfs, with the most features.
-
 ## Features
 
 * Works across operating systems: Tested with **Linux**, **FreeBSD/FreeNAS** and **SmartOS**.
@@ -34,6 +32,9 @@ zfs-autobackup tries to be the easiest to use backup tool for zfs, with the most
 * Can be scheduled via a simple cronjob or run directly from commandline.
 * Supports resuming of interrupted transfers.
 * ZFS encryption support: Can decrypt / encrypt or even re-encrypt datasets during transfer.
+* Supports sending with compression. (Using pigz, zstd etc)
+* IO buffering to speed up transfer.
+* Bandwidth rate limiting.
 * Multiple backups from and to the same datasets are no problem.
 * Creates the snapshot before doing anything else. (assuring you at least have a snapshot if all else fails)
 * Checks everything but tries continue on non-fatal errors when possible. (Reports error-count when done)
@@ -44,10 +45,11 @@ zfs-autobackup tries to be the easiest to use backup tool for zfs, with the most
 * Automatic resuming of failed transfers.
 * Can continue from existing common snapshots. (e.g. easy migration)
 * Gracefully handles datasets that no longer exist on source.
+* Support for ZFS sending/receiving through custom pipes.
 * Easy installation:
-  * Just install zfs-autobackup via pip, or download it manually.
+  * Just install zfs-autobackup via pip.
   * Only needs to be installed on one side.
-  * Written in python and uses zfs-commands, no 3rd party dependency's or libraries needed.
+  * Written in python and uses zfs-commands, no special 3rd party dependency's or compiled libraries needed.
   * No separate config files or properties. Just one zfs-autobackup command you can copy/paste in your backup script.
 
 ## Installation
@@ -64,6 +66,8 @@ The recommended way on most servers is to use [pip](https://pypi.org/project/zfs
 
 This can also be used to upgrade zfs-autobackup to the newest stable version.
 
+To install the latest beta version add the `--pre` option.
+
 ### Using easy_install
 
 On older servers you might have to use easy_install
@@ -394,6 +398,47 @@ Note 2: Decide what you want at an early stage: If you change the --encrypt or -
 
 I'll add some tips when the issues start to get in on github. :)
 
+## Transfer buffering, compression and rate limiting.
+
+If you're transferring over a slow link it might be useful to use `--compress=zstd-fast`. This will compress the data before sending, so it uses less bandwidth. An alternative to this is to use --zfs-compressed: This will transfer blocks that already have compression intact. (--compress will usually compress much better but uses much more resources. --zfs-compressed uses the least resources, but can be a disadvantage if you want to use a different compression method on the target.)
+
+You can also limit the datarate by using the `--rate` option.
+
+The `--buffer` option might also help since it acts as an IO buffer: zfs send can vary wildly between completely idle and huge bursts of data. When zfs send is idle, the buffer will continue transferring data over the slow link.
+
+It's also possible to add custom send or receive pipes with `--send-pipe` and `--recv-pipe`.
+
+These options all work together and the buffer on the receiving side is only added if appropriate. When all options are active:
+
+#### On the sending side:
+
+zfs send -> send buffer -> custom send pipes -> compression -> transfer rate limiter
+
+#### On the receiving side:
+decompression -> custom recv pipes -> buffer -> zfs recv
+
+## Running custom commands before and after snapshotting
+
+You can run commands before and after the snapshot to freeze databases to make the on for example to make the on-disk data consistent before snapshotting.
+
+The commands will be executed on the source side. Use the `--pre-snapshot-cmd` and `--post-snapshot-cmd` options for this.
+
+For example:
+
+```sh
+zfs-autobackup \
+    --pre-snapshot-cmd 'daemon -f jexec mysqljail1 mysql -s -e "set autocommit=0;flush logs;flush tables with read lock;\\! echo \$\$ > /tmp/mysql_lock.pid && sleep 60"' \
+    --pre-snapshot-cmd 'daemon -f jexec mysqljail2 mysql -s -e "set autocommit=0;flush logs;flush tables with read lock;\\! echo \$\$ > /tmp/mysql_lock.pid && sleep 60"' \
+    --post-snapshot-cmd 'pkill -F /jails/mysqljail1/tmp/mysql_lock.pid' \
+    --post-snapshot-cmd 'pkill -F /jails/mysqljail2/tmp/mysql_lock.pid' \
+    backupfs1
+```
+
+Failure handling during pre/post commands:
+
+* If a pre-command fails, zfs-autobackup will exit with an error. (after executing the post-commands)
+* All post-commands are always executed. Even if the pre-commands or actual snapshot have failed. This way you can be sure that stuff is always cleanedup and unfreezed.
+
 ## Tips
 
 * Use ```--debug``` if something goes wrong and you want to see the commands that are executed. This will also stop at the first error.
@@ -406,6 +451,8 @@ I'll add some tips when the issues start to get in on github. :)
 
 If you have a large number of datasets its important to keep the following tips in mind.
 
+Also it might help to use the --buffer option to add IO buffering during the data transfer. This might speed up things since it smooths out sudden IO bursts that are frequent during a zfs send or recv.
+
 #### Some statistics
 
 To get some idea of how fast zfs-autobackup is, I did some test on my laptop, with a SKHynix_HFS512GD9TNI-L2B0B disk. I'm using zfs 2.0.2.  
@@ -466,17 +513,32 @@ Look in man ssh_config for many more options.
 (NOTE: Quite a lot has changed since the current stable version 3.0. The page your are viewing is for upcoming version 3.1 which is still in beta.)
 
 ```console
-usage: zfs-autobackup [-h] [--ssh-config CONFIG-FILE] [--ssh-source USER@HOST] [--ssh-target USER@HOST] [--keep-source SCHEDULE] [--keep-target SCHEDULE] [--other-snapshots] [--no-snapshot] [--no-send]
-                   [--no-thinning] [--no-holds] [--min-change BYTES] [--allow-empty] [--ignore-replicated] [--strip-path N] [--clear-refreservation] [--clear-mountpoint] [--filter-properties PROPERY,...]
-                   [--set-properties PROPERTY=VALUE,...] [--rollback] [--destroy-incompatible] [--destroy-missing SCHEDULE] [--ignore-transfer-errors] [--decrypt] [--encrypt] [--test] [--verbose] [--debug]
-                   [--debug-output] [--progress] [--send-pipe COMMAND] [--recv-pipe COMMAND]
+usage: zfs-autobackup [-h] [--ssh-config CONFIG-FILE] [--ssh-source USER@HOST]
+                      [--ssh-target USER@HOST] [--keep-source SCHEDULE]
+                      [--keep-target SCHEDULE] [--pre-snapshot-cmd COMMAND]
+                      [--post-snapshot-cmd COMMAND] [--other-snapshots]
+                      [--no-snapshot] [--no-send] [--no-thinning] [--no-holds]
+                      [--min-change BYTES] [--allow-empty]
+                      [--ignore-replicated] [--strip-path N]
+                      [--clear-refreservation] [--clear-mountpoint]
+                      [--filter-properties PROPERY,...]
+                      [--set-properties PROPERTY=VALUE,...] [--rollback]
+                      [--destroy-incompatible] [--destroy-missing SCHEDULE]
+                      [--ignore-transfer-errors] [--decrypt] [--encrypt]
+                      [--test] [--verbose] [--debug] [--debug-output]
+                      [--progress] [--send-pipe COMMAND] [--recv-pipe COMMAND]
+                      [--compress TYPE] [--rate DATARATE] [--buffer SIZE]
                       backup-name [target-path]
 
-zfs-autobackup v3.1-beta3 - Copyright 2020 E.H.Eefting (edwin@datux.nl)
+zfs-autobackup v3.1-beta6 - (c)2021 E.H.Eefting (edwin@datux.nl)
 
 positional arguments:
-  backup-name           Name of the backup (you should set the zfs property "autobackup:backup-name" to true on filesystems you want to backup
-  target-path           Target ZFS filesystem (optional: if not specified, zfs-autobackup will only operate as snapshot-tool on source)
+  backup-name           Name of the backup (you should set the zfs property
+                        "autobackup:backup-name" to true on filesystems you
+                        want to backup
+  target-path           Target ZFS filesystem (optional: if not specified,
+                        zfs-autobackup will only operate as snapshot-tool on
+                        source)
 
 optional arguments:
   -h, --help            show this help message and exit
@@ -487,41 +549,84 @@ optional arguments:
   --ssh-target USER@HOST
                         Target host to push backup to.
   --keep-source SCHEDULE
-                        Thinning schedule for old source snapshots. Default: 10,1d1w,1w1m,1m1y
+                        Thinning schedule for old source snapshots. Default:
+                        10,1d1w,1w1m,1m1y
   --keep-target SCHEDULE
-                        Thinning schedule for old target snapshots. Default: 10,1d1w,1w1m,1m1y
-  --other-snapshots     Send over other snapshots as well, not just the ones created by this tool.
-  --no-snapshot         Don't create new snapshots (useful for finishing uncompleted backups, or cleanups)
-  --no-send             Don't send snapshots (useful for cleanups, or if you want a serperate send-cronjob)
+                        Thinning schedule for old target snapshots. Default:
+                        10,1d1w,1w1m,1m1y
+  --pre-snapshot-cmd COMMAND
+                        Run COMMAND before snapshotting (can be used multiple
+                        times.
+  --post-snapshot-cmd COMMAND
+                        Run COMMAND after snapshotting (can be used multiple
+                        times.
+  --other-snapshots     Send over other snapshots as well, not just the ones
+                        created by this tool.
+  --no-snapshot         Don't create new snapshots (useful for finishing
+                        uncompleted backups, or cleanups)
+  --no-send             Don't send snapshots (useful for cleanups, or if you
+                        want a serperate send-cronjob)
   --no-thinning         Do not destroy any snapshots.
-  --no-holds            Don't hold snapshots. (Faster. Allows you to destroy common snapshot.)
-  --min-change BYTES    Number of bytes written after which we consider a dataset changed (default 1)
-  --allow-empty         If nothing has changed, still create empty snapshots. (same as --min-change=0)
-  --ignore-replicated   Ignore datasets that seem to be replicated some other way. (No changes since lastest snapshot. Useful for proxmox HA replication)
-  --strip-path N        Number of directories to strip from target path (use 1 when cloning zones between 2 SmartOS machines)
+  --no-holds            Don't hold snapshots. (Faster. Allows you to destroy
+                        common snapshot.)
+  --min-change BYTES    Number of bytes written after which we consider a
+                        dataset changed (default 1)
+  --allow-empty         If nothing has changed, still create empty snapshots.
+                        (same as --min-change=0)
+  --ignore-replicated   Ignore datasets that seem to be replicated some other
+                        way. (No changes since lastest snapshot. Useful for
+                        proxmox HA replication)
+
+  --strip-path N        Number of directories to strip from target path (use 1
+                        when cloning zones between 2 SmartOS machines)
   --clear-refreservation
-                        Filter "refreservation" property. (recommended, safes space. same as --filter-properties refreservation)
-  --clear-mountpoint    Set property canmount=noauto for new datasets. (recommended, prevents mount conflicts. same as --set-properties canmount=noauto)
+                        Filter "refreservation" property. (recommended, safes
+                        space. same as --filter-properties refreservation)
+  --clear-mountpoint    Set property canmount=noauto for new datasets.
+                        (recommended, prevents mount conflicts. same as --set-
+                        properties canmount=noauto)
   --filter-properties PROPERY,...
-                        List of properties to "filter" when receiving filesystems. (you can still restore them with zfs inherit -S)
+                        List of properties to "filter" when receiving
+                        filesystems. (you can still restore them with zfs
+                        inherit -S)
   --set-properties PROPERTY=VALUE,...
-                        List of propererties to override when receiving filesystems. (you can still restore them with zfs inherit -S)
-  --rollback            Rollback changes to the latest target snapshot before starting. (normally you can prevent changes by setting the readonly property on the target_path to on)
+                        List of propererties to override when receiving
+                        filesystems. (you can still restore them with zfs
+                        inherit -S)
+  --rollback            Rollback changes to the latest target snapshot before
+                        starting. (normally you can prevent changes by setting
+                        the readonly property on the target_path to on)
   --destroy-incompatible
-                        Destroy incompatible snapshots on target. Use with care! (implies --rollback)
+                        Destroy incompatible snapshots on target. Use with
+                        care! (implies --rollback)
   --destroy-missing SCHEDULE
-                        Destroy datasets on target that are missing on the source. Specify the time since the last snapshot, e.g: --destroy-missing 30d
+                        Destroy datasets on target that are missing on the
+                        source. Specify the time since the last snapshot, e.g:
+                        --destroy-missing 30d
   --ignore-transfer-errors
-                        Ignore transfer errors (still checks if received filesystem exists. useful for acltype errors)
+                        Ignore transfer errors (still checks if received
+                        filesystem exists. useful for acltype errors)
   --decrypt             Decrypt data before sending it over.
   --encrypt             Encrypt data after receiving it.
-  --test                dont change anything, just show what would be done (still does all read-only operations)
+  --test                dont change anything, just show what would be done
+                        (still does all read-only operations)
   --verbose             verbose output
-  --debug               Show zfs commands that are executed, stops after an exception.
+  --debug               Show zfs commands that are executed, stops after an
+                        exception.
   --debug-output        Show zfs commands and their output/exit codes. (noisy)
-  --progress            show zfs progress output. Enabled automaticly on ttys. (use --no-progress to disable)
-  --send-pipe COMMAND   pipe zfs send output through COMMAND
-  --recv-pipe COMMAND   pipe zfs recv input through COMMAND
+  --progress            show zfs progress output. Enabled automaticly on ttys.
+                        (use --no-progress to disable)
+  --send-pipe COMMAND   pipe zfs send output through COMMAND (can be used
+                        multiple times)
+  --recv-pipe COMMAND   pipe zfs recv input through COMMAND (can be used
+                        multiple times)
+  --compress TYPE       Use compression during transfer, zstd-fast
+                        recommended. (zstd-slow, xz, pigz-fast, lz4, pigz-
+                        slow, zstd-fast, gzip, lzo)
+  --rate DATARATE       Limit data transfer rate (e.g. 128K. requires
+                        mbuffer.)
+  --buffer SIZE         Add zfs send and recv buffers to smooth out IO bursts.
+                        (e.g. 128M. requires mbuffer)
 
 Full manual at: https://github.com/psy0rz/zfs_autobackup
 ```

tests/basetest.py

@@ -1,4 +1,6 @@
 
+# To run tests as non-root, use this hack:
+# chmod 4755 /usr/sbin/zpool /usr/sbin/zfs
 
 import subprocess
 import random

tests/test_cmdpipe.py

@@ -1,5 +1,5 @@
 from basetest import *
-from zfs_autobackup.CmdPipe import CmdPipe
+from zfs_autobackup.CmdPipe import CmdPipe,CmdItem
 
 
 class TestCmdPipe(unittest2.TestCase):
@@ -9,24 +9,24 @@ class TestCmdPipe(unittest2.TestCase):
         p=CmdPipe(readonly=False, inp=None)
         err=[]
         out=[]
-        p.add(["ls", "-d", "/", "/", "/nonexistent"], stderr_handler=lambda line: err.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2))
+        p.add(CmdItem(["ls", "-d", "/", "/", "/nonexistent"], stderr_handler=lambda line: err.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2)))
         executed=p.execute(stdout_handler=lambda line: out.append(line))
 
         self.assertEqual(err, ["ls: cannot access '/nonexistent': No such file or directory"])
         self.assertEqual(out, ["/","/"])
-        self.assertTrue(executed)
+        self.assertIsNone(executed)
 
     def test_input(self):
         """test stdinput"""
         p=CmdPipe(readonly=False, inp="test")
         err=[]
         out=[]
-        p.add(["echo", "test"], stderr_handler=lambda line: err.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0))
+        p.add(CmdItem(["cat"], stderr_handler=lambda line: err.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0)))
         executed=p.execute(stdout_handler=lambda line: out.append(line))
 
         self.assertEqual(err, [])
         self.assertEqual(out, ["test"])
-        self.assertTrue(executed)
+        self.assertIsNone(executed)
 
     def test_pipe(self):
         """test piped"""
@@ -35,16 +35,16 @@ class TestCmdPipe(unittest2.TestCase):
         err2=[]
         err3=[]
         out=[]
-        p.add(["echo", "test"], stderr_handler=lambda line: err1.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0))
-        p.add(["tr", "e", "E"], stderr_handler=lambda line: err2.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0))
-        p.add(["tr", "t", "T"], stderr_handler=lambda line: err3.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0))
+        p.add(CmdItem(["echo", "test"], stderr_handler=lambda line: err1.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0)))
+        p.add(CmdItem(["tr", "e", "E"], stderr_handler=lambda line: err2.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0)))
+        p.add(CmdItem(["tr", "t", "T"], stderr_handler=lambda line: err3.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,0)))
         executed=p.execute(stdout_handler=lambda line: out.append(line))
 
         self.assertEqual(err1, [])
         self.assertEqual(err2, [])
         self.assertEqual(err3, [])
         self.assertEqual(out, ["TEsT"])
-        self.assertTrue(executed)
+        self.assertIsNone(executed)
 
         #test str representation as well
         self.assertEqual(str(p), "(echo test) | (tr e E) | (tr t T)")
@@ -56,16 +56,16 @@ class TestCmdPipe(unittest2.TestCase):
         err2=[]
         err3=[]
         out=[]
-        p.add(["ls", "/nonexistent1"], stderr_handler=lambda line: err1.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2))
-        p.add(["ls", "/nonexistent2"], stderr_handler=lambda line: err2.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2))
-        p.add(["ls", "/nonexistent3"], stderr_handler=lambda line: err3.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2))
+        p.add(CmdItem(["ls", "/nonexistent1"], stderr_handler=lambda line: err1.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2)))
+        p.add(CmdItem(["ls", "/nonexistent2"], stderr_handler=lambda line: err2.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2)))
+        p.add(CmdItem(["ls", "/nonexistent3"], stderr_handler=lambda line: err3.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2)))
         executed=p.execute(stdout_handler=lambda line: out.append(line))
 
         self.assertEqual(err1, ["ls: cannot access '/nonexistent1': No such file or directory"])
         self.assertEqual(err2, ["ls: cannot access '/nonexistent2': No such file or directory"])
         self.assertEqual(err3, ["ls: cannot access '/nonexistent3': No such file or directory"])
         self.assertEqual(out, [])
-        self.assertTrue(executed)
+        self.assertIsNone(executed)
 
     def test_exitcode(self):
         """test piped exitcodes """
@@ -74,16 +74,16 @@ class TestCmdPipe(unittest2.TestCase):
         err2=[]
         err3=[]
         out=[]
-        p.add(["bash", "-c", "exit 1"], stderr_handler=lambda line: err1.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,1))
-        p.add(["bash", "-c", "exit 2"], stderr_handler=lambda line: err2.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2))
-        p.add(["bash", "-c", "exit 3"], stderr_handler=lambda line: err3.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,3))
+        p.add(CmdItem(["bash", "-c", "exit 1"], stderr_handler=lambda line: err1.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,1)))
+        p.add(CmdItem(["bash", "-c", "exit 2"], stderr_handler=lambda line: err2.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,2)))
+        p.add(CmdItem(["bash", "-c", "exit 3"], stderr_handler=lambda line: err3.append(line), exit_handler=lambda exit_code: self.assertEqual(exit_code,3)))
         executed=p.execute(stdout_handler=lambda line: out.append(line))
 
         self.assertEqual(err1, [])
         self.assertEqual(err2, [])
         self.assertEqual(err3, [])
         self.assertEqual(out, [])
-        self.assertTrue(executed)
+        self.assertIsNone(executed)
 
     def test_readonly_execute(self):
         """everything readonly, just should execute"""
@@ -92,16 +92,18 @@ class TestCmdPipe(unittest2.TestCase):
         err1=[]
         err2=[]
         out=[]
-        p.add(["echo", "test1"], stderr_handler=lambda line: err1.append(line), readonly=True)
-        p.add(["echo", "test2"], stderr_handler=lambda line: err2.append(line), readonly=True)
+
+        def true_exit(exit_code):
+            return True
+
+        p.add(CmdItem(["echo", "test1"], stderr_handler=lambda line: err1.append(line), exit_handler=true_exit, readonly=True))
+        p.add(CmdItem(["echo", "test2"], stderr_handler=lambda line: err2.append(line), exit_handler=true_exit, readonly=True))
         executed=p.execute(stdout_handler=lambda line: out.append(line))
 
         self.assertEqual(err1, [])
         self.assertEqual(err2, [])
         self.assertEqual(out, ["test2"])
         self.assertTrue(executed)
-        self.assertEqual(p.items[0]['process'].returncode,0)
-        self.assertEqual(p.items[1]['process'].returncode,0)
 
     def test_readonly_skip(self):
         """one command not readonly, skip"""
@@ -110,12 +112,12 @@ class TestCmdPipe(unittest2.TestCase):
         err1=[]
         err2=[]
         out=[]
-        p.add(["echo", "test1"], stderr_handler=lambda line: err1.append(line), readonly=False)
-        p.add(["echo", "test2"], stderr_handler=lambda line: err2.append(line), readonly=True)
+        p.add(CmdItem(["echo", "test1"], stderr_handler=lambda line: err1.append(line), readonly=False))
+        p.add(CmdItem(["echo", "test2"], stderr_handler=lambda line: err2.append(line), readonly=True))
         executed=p.execute(stdout_handler=lambda line: out.append(line))
 
         self.assertEqual(err1, [])
         self.assertEqual(err2, [])
         self.assertEqual(out, [])
-        self.assertFalse(executed)
+        self.assertTrue(executed)
 

tests/test_encryption.py

@@ -49,12 +49,12 @@ class TestZfsEncryption(unittest2.TestCase):
         self.prepare_encrypted_dataset("22222222", "test_target1/encryptedtarget")
 
         with patch('time.strftime', return_value="20101111000000"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --allow-empty".split(" ")).run())
-            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --no-snapshot".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --allow-empty --exclude-received".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --no-snapshot --exclude-received".split(" ")).run())
 
         with patch('time.strftime', return_value="20101111000001"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --allow-empty".split(" ")).run())
-            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --no-snapshot".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --allow-empty --exclude-received".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --no-snapshot --exclude-received".split(" ")).run())
 
         r = shelltest("zfs get -r -t filesystem encryptionroot test_target1")
         self.assertMultiLineEqual(r,"""
@@ -86,12 +86,12 @@ test_target1/test_source2/fs2/sub                                     encryption
         self.prepare_encrypted_dataset("22222222", "test_target1/encryptedtarget")
 
         with patch('time.strftime', return_value="20101111000000"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --decrypt --allow-empty".split(" ")).run())
-            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --decrypt --no-snapshot".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --decrypt --allow-empty --exclude-received".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --decrypt --no-snapshot --exclude-received".split(" ")).run())
 
         with patch('time.strftime', return_value="20101111000001"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --decrypt --allow-empty".split(" ")).run())
-            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --decrypt --no-snapshot".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --decrypt --allow-empty --exclude-received".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --decrypt --no-snapshot --exclude-received".split(" ")).run())
 
         r = shelltest("zfs get -r -t filesystem encryptionroot test_target1")
         self.assertEqual(r, """
@@ -121,12 +121,12 @@ test_target1/test_source2/fs2/sub                              encryptionroot  -
         self.prepare_encrypted_dataset("22222222", "test_target1/encryptedtarget")
 
         with patch('time.strftime', return_value="20101111000000"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --encrypt --debug --allow-empty".split(" ")).run())
-            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --encrypt --debug --no-snapshot".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --encrypt --debug --allow-empty --exclude-received".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --encrypt --debug --no-snapshot --exclude-received".split(" ")).run())
 
         with patch('time.strftime', return_value="20101111000001"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --encrypt --debug --allow-empty".split(" ")).run())
-            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --encrypt --debug --no-snapshot".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-progress --encrypt --debug --allow-empty --exclude-received".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1/encryptedtarget --verbose --no-progress --encrypt --debug --no-snapshot --exclude-received".split(" ")).run())
 
         r = shelltest("zfs get -r -t filesystem encryptionroot test_target1")
         self.assertEqual(r, """
@@ -157,16 +157,16 @@ test_target1/test_source2/fs2/sub                              encryptionroot  -
 
         with patch('time.strftime', return_value="20101111000000"):
             self.assertFalse(ZfsAutobackup(
-                "test test_target1 --verbose --no-progress --decrypt --encrypt --debug --allow-empty".split(" ")).run())
+                "test test_target1 --verbose --no-progress --decrypt --encrypt --debug --allow-empty --exclude-received".split(" ")).run())
             self.assertFalse(ZfsAutobackup(
-                "test test_target1/encryptedtarget --verbose --no-progress --decrypt --encrypt --debug --no-snapshot".split(
+                "test test_target1/encryptedtarget --verbose --no-progress --decrypt --encrypt --debug --no-snapshot --exclude-received".split(
                     " ")).run())
 
         with patch('time.strftime', return_value="20101111000001"):
             self.assertFalse(ZfsAutobackup(
-                "test test_target1 --verbose --no-progress --decrypt --encrypt --debug --allow-empty".split(" ")).run())
+                "test test_target1 --verbose --no-progress --decrypt --encrypt --debug --allow-empty --exclude-received".split(" ")).run())
             self.assertFalse(ZfsAutobackup(
-                "test test_target1/encryptedtarget --verbose --no-progress --decrypt --encrypt --debug --no-snapshot".split(
+                "test test_target1/encryptedtarget --verbose --no-progress --decrypt --encrypt --debug --no-snapshot --exclude-received".split(
                     " ")).run())
 
         r = shelltest("zfs get -r -t filesystem encryptionroot test_target1")

tests/test_executenode.py

@@ -26,9 +26,9 @@ class TestExecuteNode(unittest2.TestCase):
         with self.subTest("multiline tabsplit"):
             self.assertEqual(node.run(["echo","l1c1\tl1c2\nl2c1\tl2c2"], tab_split=True), [['l1c1', 'l1c2'], ['l2c1', 'l2c2']])
 
-        #escaping test (shouldnt be a problem locally, single quotes can be a problem remote via ssh)
+        #escaping test
         with self.subTest("escape test"):
-            s="><`'\"@&$()$bla\\/.*!#test _+-={}[]|"
+            s="><`'\"@&$()$bla\\/.* !#test _+-={}[]|${bla} $bla"
             self.assertEqual(node.run(["echo",s]), [s])
 
         #return std err as well, trigger stderr by listing something non existing
@@ -51,6 +51,15 @@ class TestExecuteNode(unittest2.TestCase):
         with self.subTest("stdin process with inp=None (shouldn't hang)"):
             self.assertEqual(node.run(["cat"]), [])
 
+        # let the system do the piping with an unescaped |:
+        with self.subTest("system piping test"):
+
+            #first make sure the actual | character is still properly escaped:
+            self.assertEqual(node.run(["echo","|"]), ["|"])
+
+            #now pipe
+            self.assertEqual(node.run(["echo", "abc", node.PIPE, "tr", "a", "A" ]), ["Abc"])
+
     def test_basics_local(self):
         node=ExecuteNode(debug_output=True)
         self.basics(node)

tests/test_externalfailures.py

@@ -227,11 +227,11 @@ test_target1/test_source2/fs2/sub@test-20101111000000
                 # incremental, doesnt want previous anymore
                 with patch('time.strftime', return_value="20101111000002"):
                     self.assertFalse(ZfsAutobackup(
-                        "test test_target1 --no-progress --verbose --keep-target=0 --debug --allow-empty".split(" ")).run())
+                        "test test_target1 --no-progress --verbose --keep-target=0 --allow-empty".split(" ")).run())
 
             print(buf.getvalue())
 
-            self.assertIn(": aborting resume, since", buf.getvalue())
+            self.assertIn("Aborting resume, we dont want that snapshot anymore.", buf.getvalue())
 
         r = shelltest("zfs list -H -o name -r -t all test_target1")
         self.assertMultiLineEqual(r, """
@@ -247,6 +247,34 @@ test_target1/test_source2/fs2/sub
 test_target1/test_source2/fs2/sub@test-20101111000002
 """)
 
+    # test with empty snapshot list (this was a bug)
+    def test_abort_resume_emptysnapshotlist(self):
+
+        if "0.6.5" in ZFS_USERSPACE:
+            self.skipTest("Resume not supported in this ZFS userspace version")
+
+        with patch('time.strftime', return_value="20101111000000"):
+            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose".split(" ")).run())
+
+        # generate resume
+        with patch('time.strftime', return_value="20101111000001"):
+            self.generate_resume()
+
+        shelltest("zfs destroy test_source1/fs1@test-20101111000001")
+
+        with OutputIO() as buf:
+            with redirect_stdout(buf):
+                # incremental, doesnt want previous anymore
+                with patch('time.strftime', return_value="20101111000002"):
+                    self.assertFalse(ZfsAutobackup(
+                        "test test_target1 --no-progress --verbose --no-snapshot".split(
+                            " ")).run())
+
+            print(buf.getvalue())
+
+            self.assertIn("Aborting resume, its obsolete", buf.getvalue())
+
+
     def test_missing_common(self):
 
         with patch('time.strftime', return_value="20101111000000"):

tests/test_regressions.py

@@ -8,12 +8,51 @@ class TestZfsNode(unittest2.TestCase):
         prepare_zpools()
         self.longMessage=True
 
-    # #resume initial backup
-    # def test_keepsource0(self):
+    def test_keepsource0target10queuedsend(self):
+        """Test if thinner doesnt destroy too much early on if there are no common snapshots YET. Issue #84"""
 
-    #     #somehow only specifying --allow-empty --keep-source 0 failed:
-    #     with patch('time.strftime', return_value="20101111000000"):
-    #         self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --keep-source 0".split(" ")).run())
+        with patch('time.strftime', return_value="20101111000000"):
+            self.assertFalse(ZfsAutobackup(
+                "test test_target1 --no-progress --verbose --keep-source=0 --keep-target=10 --allow-empty --no-send".split(
+                    " ")).run())
 
-    #     with patch('time.strftime', return_value="20101111000001"):
-    #         self.assertFalse(ZfsAutobackup("test test_target1 --verbose --allow-empty --keep-source 0".split(" ")).run())
+        with patch('time.strftime', return_value="20101111000001"):
+            self.assertFalse(ZfsAutobackup(
+                "test test_target1 --no-progress --verbose --keep-source=0 --keep-target=10 --allow-empty --no-send".split(
+                    " ")).run())
+
+        with patch('time.strftime', return_value="20101111000002"):
+            self.assertFalse(ZfsAutobackup(
+                "test test_target1 --no-progress --verbose --keep-source=0 --keep-target=10 --allow-empty".split(
+                    " ")).run())
+
+        r = shelltest("zfs list -H -o name -r -t all " + TEST_POOLS)
+        self.assertMultiLineEqual(r, """
+test_source1
+test_source1/fs1
+test_source1/fs1@test-20101111000002
+test_source1/fs1/sub
+test_source1/fs1/sub@test-20101111000002
+test_source2
+test_source2/fs2
+test_source2/fs2/sub
+test_source2/fs2/sub@test-20101111000002
+test_source2/fs3
+test_source2/fs3/sub
+test_target1
+test_target1/test_source1
+test_target1/test_source1/fs1
+test_target1/test_source1/fs1@test-20101111000000
+test_target1/test_source1/fs1@test-20101111000001
+test_target1/test_source1/fs1@test-20101111000002
+test_target1/test_source1/fs1/sub
+test_target1/test_source1/fs1/sub@test-20101111000000
+test_target1/test_source1/fs1/sub@test-20101111000001
+test_target1/test_source1/fs1/sub@test-20101111000002
+test_target1/test_source2
+test_target1/test_source2/fs2
+test_target1/test_source2/fs2/sub
+test_target1/test_source2/fs2/sub@test-20101111000000
+test_target1/test_source2/fs2/sub@test-20101111000001
+test_target1/test_source2/fs2/sub@test-20101111000002
+""")

tests/test_sendrecvpipes.py

@@ -0,0 +1,88 @@
+import zfs_autobackup.compressors
+from basetest import *
+import time
+
+class TestSendRecvPipes(unittest2.TestCase):
+    """test input/output pipes for zfs send and recv"""
+
+    def setUp(self):
+        prepare_zpools()
+        self.longMessage=True
+
+
+
+    def test_send_basics(self):
+        """send basics (remote/local send pipe)"""
+
+
+        with self.subTest("local local pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1", "--exclude-received", "--no-holds", "--no-progress", "--send-pipe=dd bs=1M",  "--recv-pipe=dd bs=2M"]).run())
+
+            shelltest("zfs destroy -r test_target1/test_source1/fs1/sub")
+
+        with self.subTest("remote local pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1", "--exclude-received", "--no-holds", "--no-progress", "--ssh-source=localhost", "--send-pipe=dd bs=1M",  "--recv-pipe=dd bs=2M"]).run())
+
+            shelltest("zfs destroy -r test_target1/test_source1/fs1/sub")
+
+        with self.subTest("local remote pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1",  "--exclude-received", "--no-holds", "--no-progress", "--ssh-target=localhost", "--send-pipe=dd bs=1M",  "--recv-pipe=dd bs=2M"]).run())
+
+            shelltest("zfs destroy -r test_target1/test_source1/fs1/sub")
+
+        with self.subTest("remote remote pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1",  "--exclude-received", "--no-holds", "--no-progress", "--ssh-source=localhost", "--ssh-target=localhost", "--send-pipe=dd bs=1M",  "--recv-pipe=dd bs=2M"]).run())
+
+    def test_compress(self):
+        """send basics (remote/local send pipe)"""
+
+        for compress in zfs_autobackup.compressors.COMPRESS_CMDS.keys():
+
+            with self.subTest("compress "+compress):
+                with patch('time.strftime', return_value="20101111000000"):
+                    self.assertFalse(ZfsAutobackup(["test", "test_target1", "--exclude-received", "--no-holds", "--no-progress", "--compress="+compress]).run())
+
+                shelltest("zfs destroy -r test_target1/test_source1/fs1/sub")
+
+    def test_buffer(self):
+        """test different buffer configurations"""
+
+
+        with self.subTest("local local pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1", "--exclude-received", "--no-holds", "--no-progress", "--buffer=1M" ]).run())
+
+            shelltest("zfs destroy -r test_target1/test_source1/fs1/sub")
+
+        with self.subTest("remote local pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1", "--exclude-received", "--no-holds", "--no-progress", "--ssh-source=localhost", "--buffer=1M"]).run())
+
+            shelltest("zfs destroy -r test_target1/test_source1/fs1/sub")
+
+        with self.subTest("local remote pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1",  "--exclude-received", "--no-holds", "--no-progress", "--ssh-target=localhost", "--buffer=1M"]).run())
+
+            shelltest("zfs destroy -r test_target1/test_source1/fs1/sub")
+
+        with self.subTest("remote remote pipe"):
+            with patch('time.strftime', return_value="20101111000000"):
+                self.assertFalse(ZfsAutobackup(["test", "test_target1",  "--exclude-received", "--no-holds", "--no-progress", "--ssh-source=localhost", "--ssh-target=localhost", "--buffer=1M"]).run())
+
+    def test_rate(self):
+        """test rate limit"""
+
+
+        start=time.time()
+        with patch('time.strftime', return_value="20101111000000"):
+            self.assertFalse(ZfsAutobackup(["test", "test_target1", "--exclude-received", "--no-holds", "--no-progress", "--rate=50k" ]).run())
+
+        #not a great way of verifying but it works.
+        self.assertGreater(time.time()-start, 5)
+
+

tests/test_zfsautobackup.py

@@ -312,8 +312,6 @@ test_target1/test_source2/fs2
             self.assertFalse(ZfsAutobackup("test test_target1 --verbose --no-send --no-progress".split(" ")).run())
 
             r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
-            #(only parents are created )
-            #TODO: it probably shouldn't create these
             self.assertMultiLineEqual(r,"""
 test_source1
 test_source1/fs1
@@ -337,8 +335,6 @@ test_target1
             self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --ignore-replicated".split(" ")).run())
 
             r=shelltest("zfs list -H -o name -r -t all "+TEST_POOLS)
-            #(only parents are created )
-            #TODO: it probably shouldn't create these
             self.assertMultiLineEqual(r,"""
 test_source1
 test_source1/fs1
@@ -590,10 +586,10 @@ test_target1/test_source2/fs2/sub@test-20101111000003
         #test all ssh directions
 
         with patch('time.strftime', return_value="20101111000000"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty --ssh-source localhost".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty --ssh-source localhost --exclude-received".split(" ")).run())
 
         with patch('time.strftime', return_value="20101111000001"):
-            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty --ssh-target localhost".split(" ")).run())
+            self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty --ssh-target localhost --exclude-received".split(" ")).run())
 
         with patch('time.strftime', return_value="20101111000002"):
             self.assertFalse(ZfsAutobackup("test test_target1 --no-progress --verbose --allow-empty --ssh-source localhost --ssh-target localhost".split(" ")).run())
@@ -851,7 +847,7 @@ test_target1/test_source2/fs2/sub@test-20101111000003
 """)
 
 
-        # make snapshot 4, since we used no-holds, it will delete 3 on the source, breaking the backup
+        # run with snapshot-only for 4, since we used no-holds, it will delete 3 on the source, breaking the backup
         with patch('time.strftime', return_value="20101111000004"):
             self.assertFalse(ZfsAutobackup("test --no-progress --verbose --keep-source=0 --keep-target=0 --allow-empty".split(" ")).run())
 
@@ -890,7 +886,7 @@ test_target1/test_source2/fs2/sub@test-20101111000003
         n=ZfsNode("test",l)
         d=ZfsDataset(n,"test_source1@test")
 
-        sp=d.send_pipe([], prev_snapshot=None, resume_token=None, show_progress=True, raw=False, output_pipes=[], send_properties=True, write_embedded=True)
+        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)
 
 
         with OutputIO() as buf:

tests/test_zfsautobackup31.py

@@ -2,6 +2,7 @@ from basetest import *
 import time
 
 class TestZfsAutobackup31(unittest2.TestCase):
+    """various new 3.1 features"""
 
     def setUp(self):
         prepare_zpools()
@@ -47,3 +48,34 @@ test_target1/test_source2/fs2/sub@test-20101111000001
 """)
 
 
+    def test_re_replication(self):
+        """test re-replication of something thats already a backup (new in v3.1-beta5)"""
+
+        shelltest("zfs create test_target1/a")
+        shelltest("zfs create test_target1/b")
+
+        with patch('time.strftime', return_value="20101111000000"):
+            self.assertFalse(ZfsAutobackup("test test_target1/a --no-progress --verbose --debug".split(" ")).run())
+
+        with patch('time.strftime', return_value="20101111000001"):
+            self.assertFalse(ZfsAutobackup("test test_target1/b --no-progress --verbose".split(" ")).run())
+
+            r=shelltest("zfs list -H -o name -r -t snapshot test_target1")
+            #NOTE: it wont backup test_target1/a/test_source2/fs2/sub to test_target1/b since it doesnt have the zfs_autobackup property anymore.
+            self.assertMultiLineEqual(r,"""
+test_target1/a/test_source1/fs1@test-20101111000000
+test_target1/a/test_source1/fs1/sub@test-20101111000000
+test_target1/a/test_source2/fs2/sub@test-20101111000000
+test_target1/b/test_source1/fs1@test-20101111000000
+test_target1/b/test_source1/fs1/sub@test-20101111000000
+test_target1/b/test_source2/fs2/sub@test-20101111000000
+test_target1/b/test_target1/a/test_source1/fs1@test-20101111000000
+test_target1/b/test_target1/a/test_source1/fs1/sub@test-20101111000000
+""")
+
+    def test_zfs_compressed(self):
+
+        with patch('time.strftime', return_value="20101111000000"):
+            self.assertFalse(
+                ZfsAutobackup("test test_target1 --no-progress --verbose --debug --zfs-compressed".split(" ")).run())
+

tests/test_zfsnode.py

@@ -1,6 +1,6 @@
 from basetest import *
 from zfs_autobackup.LogStub import LogStub
-
+from zfs_autobackup.ExecuteNode import ExecuteError
 
 
 class TestZfsNode(unittest2.TestCase):
@@ -9,14 +9,13 @@ class TestZfsNode(unittest2.TestCase):
         prepare_zpools()
         # return super().setUp()
 
-
     def test_consistent_snapshot(self):
         logger = LogStub()
         description = "[Source]"
         node = ZfsNode("test", logger, description=description)
 
         with self.subTest("first snapshot"):
-            node.consistent_snapshot(node.selected_datasets, "test-1",100000)
+            node.consistent_snapshot(node.selected_datasets(exclude_paths=[], exclude_received=False), "test-1", 100000)
             r = shelltest("zfs list -H -o name -r -t all " + TEST_POOLS)
             self.assertEqual(r, """
 test_source1
@@ -33,9 +32,8 @@ test_source2/fs3/sub
 test_target1
 """)
 
-
         with self.subTest("second snapshot, no changes, no snapshot"):
-            node.consistent_snapshot(node.selected_datasets, "test-2",1)
+            node.consistent_snapshot(node.selected_datasets(exclude_paths=[], exclude_received=False), "test-2", 1)
             r = shelltest("zfs list -H -o name -r -t all " + TEST_POOLS)
             self.assertEqual(r, """
 test_source1
@@ -53,7 +51,7 @@ test_target1
 """)
 
         with self.subTest("second snapshot, no changes, empty snapshot"):
-            node.consistent_snapshot(node.selected_datasets, "test-2",0)
+            node.consistent_snapshot(node.selected_datasets(exclude_paths=[], exclude_received=False), "test-2", 0)
             r = shelltest("zfs list -H -o name -r -t all " + TEST_POOLS)
             self.assertEqual(r, """
 test_source1
@@ -73,12 +71,65 @@ test_source2/fs3/sub
 test_target1
 """)
 
+    def test_consistent_snapshot_prepostcmds(self):
+        logger = LogStub()
+        description = "[Source]"
+        node = ZfsNode("test", logger, description=description, debug_output=True)
+
+        with self.subTest("Test if all cmds are executed correctly (no failures)"):
+            with OutputIO() as buf:
+                with redirect_stdout(buf):
+                    node.consistent_snapshot(node.selected_datasets(exclude_paths=[], exclude_received=False), "test-1",
+                                             0,
+                                             pre_snapshot_cmds=["echo pre1", "echo pre2"],
+                                             post_snapshot_cmds=["echo post1 >&2", "echo post2 >&2"]
+                                             )
+
+                self.assertIn("STDOUT > pre1", buf.getvalue())
+                self.assertIn("STDOUT > pre2", buf.getvalue())
+                self.assertIn("STDOUT > post1", buf.getvalue())
+                self.assertIn("STDOUT > post2", buf.getvalue())
+
+
+        with self.subTest("Failure in the middle, only pre1 and both post1 and post2 should be executed, no snapshot should be attempted"):
+            with OutputIO() as buf:
+                with redirect_stdout(buf):
+                    with self.assertRaises(ExecuteError):
+                        node.consistent_snapshot(node.selected_datasets(exclude_paths=[], exclude_received=False), "test-1",
+                                                 0,
+                                                 pre_snapshot_cmds=["echo pre1", "false", "echo pre2"],
+                                                 post_snapshot_cmds=["echo post1", "false", "echo post2"]
+                                                 )
+
+                print(buf.getvalue())
+                self.assertIn("STDOUT > pre1", buf.getvalue())
+                self.assertNotIn("STDOUT > pre2", buf.getvalue())
+                self.assertIn("STDOUT > post1", buf.getvalue())
+                self.assertIn("STDOUT > post2", buf.getvalue())
+
+        with self.subTest("Snapshot fails"):
+            with OutputIO() as buf:
+                with redirect_stdout(buf):
+                    with self.assertRaises(ExecuteError):
+                        #same snapshot name as before so it fails
+                        node.consistent_snapshot(node.selected_datasets(exclude_paths=[], exclude_received=False), "test-1",
+                                                 0,
+                                                 pre_snapshot_cmds=["echo pre1", "echo pre2"],
+                                                 post_snapshot_cmds=["echo post1", "echo post2"]
+                                                 )
+
+                print(buf.getvalue())
+                self.assertIn("STDOUT > pre1", buf.getvalue())
+                self.assertIn("STDOUT > pre2", buf.getvalue())
+                self.assertIn("STDOUT > post1", buf.getvalue())
+                self.assertIn("STDOUT > post2", buf.getvalue())
+
 
     def test_getselected(self):
         logger = LogStub()
         description = "[Source]"
         node = ZfsNode("test", logger, description=description)
-        s=pformat(node.selected_datasets)
+        s = pformat(node.selected_datasets(exclude_paths=[], exclude_received=False))
         print(s)
 
         # basics
@@ -92,13 +143,11 @@ test_target1
  (local): test_source1/fs1/sub,
  (local): test_source2/fs2/sub]""")
 
-
     def test_validcommand(self):
         logger = LogStub()
         description = "[Source]"
         node = ZfsNode("test", logger, description=description)
 
-
         with self.subTest("test invalid option"):
             self.assertFalse(node.valid_command(["zfs", "send", "--invalid-option", "nonexisting"]))
         with self.subTest("test valid option"):
@@ -111,7 +160,6 @@ test_target1
         # -D propably always supported
         self.assertGreater(len(node.supported_send_options), 0)
 
-
     def test_supportedrecvoptions(self):
         logger = LogStub()
         description = "[Source]"
@@ -120,6 +168,5 @@ test_target1
         self.assertIsInstance(node.supported_recv_options, list)
 
 
-
 if __name__ == '__main__':
     unittest.main()

zfs_autobackup/CmdPipe.py

@@ -2,6 +2,49 @@ import subprocess
 import os
 import select
 
+try:
+    from shlex import quote as cmd_quote
+except ImportError:
+    from pipes import quote as cmd_quote
+
+
+class CmdItem:
+    """one command item, to be added to a CmdPipe"""
+
+    def __init__(self, cmd, readonly=False, stderr_handler=None, exit_handler=None, shell=False):
+        """create item. caller has to make sure cmd is properly escaped when using shell.
+        :type cmd: list of str
+        """
+
+        self.cmd = cmd
+        self.readonly = readonly
+        self.stderr_handler = stderr_handler
+        self.exit_handler = exit_handler
+        self.shell = shell
+        self.process = None
+
+    def __str__(self):
+        """return copy-pastable version of command."""
+        if self.shell:
+            # its already copy pastable for a shell:
+            return " ".join(self.cmd)
+        else:
+            # make it copy-pastable, will make a mess of quotes sometimes, but is correct
+            return " ".join(map(cmd_quote, self.cmd))
+
+    def create(self, stdin):
+        """actually create the subprocess (called by CmdPipe)"""
+
+        # make sure the command gets all the data in utf8 format:
+        # (this is necessary if LC_ALL=en_US.utf8 is not set in the environment)
+        encoded_cmd = []
+        for arg in self.cmd:
+            encoded_cmd.append(arg.encode('utf-8'))
+
+        self.process = subprocess.Popen(encoded_cmd, env=os.environ, stdout=subprocess.PIPE, stdin=stdin,
+                                        stderr=subprocess.PIPE, shell=self.shell)
+
+
 class CmdPipe:
     """a pipe of one or more commands. also takes care of utf-8 encoding/decoding and line based parsing"""
 
@@ -17,42 +60,35 @@ class CmdPipe:
         self.readonly = readonly
         self._should_execute = True
 
-    def add(self, cmd, readonly=False, stderr_handler=None, exit_handler=None):
-        """adds a command to pipe"""
+    def add(self, cmd_item):
+        """adds a CmdItem to pipe.
+        :type cmd_item: CmdItem
+        """
 
-        self.items.append({
-            'cmd': cmd,
-            'stderr_handler': stderr_handler,
-            'exit_handler': exit_handler
-        })
+        self.items.append(cmd_item)
 
-        if not readonly and self.readonly:
+        if not cmd_item.readonly and self.readonly:
             self._should_execute = False
 
     def __str__(self):
-        """transform into oneliner for debugging and testing """
+        """transform whole pipe into oneliner for debugging and testing. this should generate a copy-pastable string for in a console """
 
-        #just one command?
-        if len(self.items)==1:
-            return " ".join(self.items[0]['cmd'])
-
-        #an actual pipe
         ret = ""
         for item in self.items:
             if ret:
                 ret = ret + " | "
-            ret = ret + "(" + " ".join(item['cmd']) + ")"
+            ret = ret + "({})".format(item)  # this will do proper escaping to make it copypastable
 
         return ret
 
     def should_execute(self):
-        return(self._should_execute)
+        return self._should_execute
 
     def execute(self, stdout_handler):
-        """run the pipe. returns True if it executed, and false if it skipped due to readonly conditions"""
+        """run the pipe. returns True all exit handlers returned true"""
 
         if not self._should_execute:
-            return False
+            return True
 
         # first process should have actual user input as stdin:
         selectors = []
@@ -62,28 +98,20 @@ class CmdPipe:
         stdin = subprocess.PIPE
         for item in self.items:
 
-            # make sure the command gets all the data in utf8 format:
-            # (this is necessary if LC_ALL=en_US.utf8 is not set in the environment)
-            encoded_cmd = []
-            for arg in item['cmd']:
-                encoded_cmd.append(arg.encode('utf-8'))
-
-            item['process'] = subprocess.Popen(encoded_cmd, env=os.environ, stdout=subprocess.PIPE, stdin=stdin,
-                                               stderr=subprocess.PIPE)
-
-            selectors.append(item['process'].stderr)
+            item.create(stdin)
+            selectors.append(item.process.stderr)
 
             if last_stdout is None:
                 # we're the first process in the pipe, do we have some input?
                 if self.inp is not None:
                     # TODO: make streaming to support big inputs?
-                    item['process'].stdin.write(self.inp.encode('utf-8'))
-                item['process'].stdin.close()
+                    item.process.stdin.write(self.inp.encode('utf-8'))
+                item.process.stdin.close()
             else:
                 # last stdout was piped to this stdin already, so close it because we dont need it anymore
                 last_stdout.close()
 
-            last_stdout = item['process'].stdout
+            last_stdout = item.process.stdout
             stdin = last_stdout
 
         # monitor last stdout as well
@@ -104,14 +132,14 @@ class CmdPipe:
                     eof_count = eof_count + 1
 
             for item in self.items:
-                if item['process'].stderr in read_ready:
-                    line = item['process'].stderr.readline().decode('utf-8').rstrip()
+                if item.process.stderr in read_ready:
+                    line = item.process.stderr.readline().decode('utf-8').rstrip()
                     if line != "":
-                        item['stderr_handler'](line)
+                        item.stderr_handler(line)
                     else:
                         eof_count = eof_count + 1
 
-                if item['process'].poll() is not None:
+                if item.process.poll() is not None:
                     done_count = done_count + 1
 
             # all filehandles are eof and all processes are done (poll() is not None)
@@ -121,12 +149,12 @@ class CmdPipe:
         # close filehandles
         last_stdout.close()
         for item in self.items:
-            item['process'].stderr.close()
+            item.process.stderr.close()
 
         # call exit handlers
+        success = True
         for item in self.items:
-            if item['exit_handler'] is not None:
-                item['exit_handler'](item['process'].returncode)
+            if item.exit_handler is not None:
+                success=item.exit_handler(item.process.returncode) and success
 
-
-        return True
+        return success

zfs_autobackup/ExecuteNode.py

@@ -1,16 +1,24 @@
 import os
 import select
 import subprocess
-
-from zfs_autobackup.CmdPipe import CmdPipe
+from zfs_autobackup.CmdPipe import CmdPipe, CmdItem
 from zfs_autobackup.LogStub import LogStub
 
+try:
+    from shlex import quote as cmd_quote
+except ImportError:
+    from pipes import quote as cmd_quote
+
+
 class ExecuteError(Exception):
     pass
 
+
 class ExecuteNode(LogStub):
     """an endpoint to execute local or remote commands via ssh"""
 
+    PIPE=1
+
     def __init__(self, ssh_config=None, ssh_to=None, readonly=False, debug_output=False):
         """ssh_config: custom ssh config
            ssh_to: server you want to ssh to. none means local
@@ -41,48 +49,43 @@ class ExecuteNode(LogStub):
         else:
             self.error("STDERR > " + line.rstrip())
 
-    # def _parse_stderr_pipe(self, line, hide_errors):
-    #     """parse stderr from pipe input process. can be overridden in subclass"""
-    #     if hide_errors:
-    #         self.debug("STDERR|> " + line.rstrip())
-    #     else:
-    #         self.error("STDERR|> " + line.rstrip())
+    def _quote(self, cmd):
+        """return quoted version of command. if it has value PIPE it will add an actual | """
+        if cmd==self.PIPE:
+            return('|')
+        else:
+            return(cmd_quote(cmd))
 
-    def _remote_cmd(self, cmd):
-        """transforms cmd in correct form for remote over ssh, if needed"""
+    def _shell_cmd(self, cmd):
+        """prefix specified ssh shell to command and escape shell characters"""
 
-        # use ssh?
-        if self.ssh_to is not None:
-            encoded_cmd = []
-            encoded_cmd.append("ssh")
+        ret=[]
+
+        #add remote shell
+        if not self.is_local():
+            ret=["ssh"]
 
             if self.ssh_config is not None:
-                encoded_cmd.extend(["-F", self.ssh_config])
+                ret.extend(["-F", self.ssh_config])
 
-            encoded_cmd.append(self.ssh_to)
+            ret.append(self.ssh_to)
 
-            for arg in cmd:
-                # add single quotes for remote commands to support spaces and other weird stuff (remote commands are
-                # executed in a shell) and escape existing single quotes (bash needs ' to end the quoted string,
-                # then a \' for the actual quote and then another ' to start a new quoted string) (and then python
-                # needs the double \ to get a single \)
-                encoded_cmd.append(("'" + arg.replace("'", "'\\''") + "'"))
-
-            return encoded_cmd
-        else:
-            return(cmd)
+        ret.append(" ".join(map(self._quote, cmd)))
 
+        return ret
 
     def is_local(self):
         return self.ssh_to is None
 
-
     def run(self, cmd, inp=None, tab_split=False, valid_exitcodes=None, readonly=False, hide_errors=False,
             return_stderr=False, pipe=False):
         """run a command on the node , checks output and parses/handle output and returns it
 
+        Either uses a local shell (sh -c) or remote shell (ssh) to execute the command. Therefore the command can have stuff like actual pipes in it, if you dont want to use pipe=True to pipe stuff.
+
         :param cmd: the actual command, should be a list, where the first item is the command
-                    and the rest are parameters.
+                    and the rest are parameters. use ExecuteNode.PIPE to add an unescaped |
+                    (if you want to use system piping instead of python piping)
         :param pipe: return CmdPipe instead of executing it.
         :param inp: Can be None, a string or a CmdPipe that was previously returned.
         :param tab_split: split tabbed files in output into a list
@@ -96,13 +99,14 @@ class ExecuteNode(LogStub):
 
         # create new pipe?
         if not isinstance(inp, CmdPipe):
-            p = CmdPipe(self.readonly, inp)
+            cmd_pipe = CmdPipe(self.readonly, inp)
         else:
             # add stuff to existing pipe
-            p = inp
+            cmd_pipe = inp
 
         # stderr parser
         error_lines = []
+
         def stderr_handler(line):
             if tab_split:
                 error_lines.append(line.rstrip().split('\t'))
@@ -119,18 +123,22 @@ class ExecuteNode(LogStub):
                 self.debug("EXIT   > {}".format(exit_code))
 
             if (valid_exitcodes != []) and (exit_code not in valid_exitcodes):
-             raise (ExecuteError("Command '{}' return exit code '{}' (valid codes: {})".format(" ".join(cmd), exit_code, valid_exitcodes)))
+                self.error("Command \"{}\" returned exit code {} (valid codes: {})".format(cmd_item, exit_code, valid_exitcodes))
+                return False
 
-        # add command to pipe
-        encoded_cmd = self._remote_cmd(cmd)
-        p.add(cmd=encoded_cmd, readonly=readonly, stderr_handler=stderr_handler, exit_handler=exit_handler)
+            return True
+
+        # add shell command and handlers to pipe
+        cmd_item=CmdItem(cmd=self._shell_cmd(cmd), readonly=readonly, stderr_handler=stderr_handler, exit_handler=exit_handler, shell=self.is_local())
+        cmd_pipe.add(cmd_item)
 
         # return pipe instead of executing?
         if pipe:
-            return p
+            return cmd_pipe
 
         # stdout parser
         output_lines = []
+
         def stdout_handler(line):
             if tab_split:
                 output_lines.append(line.rstrip().split('\t'))
@@ -138,13 +146,14 @@ class ExecuteNode(LogStub):
                 output_lines.append(line.rstrip())
             self._parse_stdout(line)
 
-        if p.should_execute():
-            self.debug("CMD    > {}".format(p))
+        if cmd_pipe.should_execute():
+            self.debug("CMD    > {}".format(cmd_pipe))
         else:
-            self.debug("CMDSKIP> {}".format(p))
+            self.debug("CMDSKIP> {}".format(cmd_pipe))
 
         # execute and calls handlers in CmdPipe
-        p.execute(stdout_handler=stdout_handler)
+        if not cmd_pipe.execute(stdout_handler=stdout_handler):
+            raise(ExecuteError("Last command returned error"))
 
         if return_stderr:
             return output_lines, error_lines

zfs_autobackup/LogConsole.py

@@ -31,6 +31,13 @@ class LogConsole:
             print("! " + txt, file=sys.stderr)
         sys.stderr.flush()
 
+    def warning(self, txt):
+        if self.colorama:
+            print(colorama.Fore.YELLOW + colorama.Style.BRIGHT + "  NOTE: " + txt + colorama.Style.RESET_ALL)
+        else:
+            print("  NOTE: " + txt)
+        sys.stdout.flush()
+
     def verbose(self, txt):
         if self.show_verbose:
             if self.colorama:
@@ -46,3 +53,14 @@ class LogConsole:
             else:
                 print("# " + txt)
             sys.stdout.flush()
+
+    def progress(self, txt):
+        """print progress output to stderr (stays on same line)"""
+        self.clear_progress()
+        print(">>> {}\r".format(txt), end='', file=sys.stderr)
+        sys.stderr.flush()
+
+    def clear_progress(self):
+        import colorama
+        print(colorama.ansi.clear_line(), end='', file=sys.stderr)
+        sys.stderr.flush()

zfs_autobackup/LogStub.py

@@ -11,5 +11,8 @@ class LogStub:
     def verbose(self, txt):
         print("VERBOSE: " + txt)
 
+    def warning(self, txt):
+        print("WARNING: " + txt)
+
     def error(self, txt):
         print("ERROR  : " + txt)

zfs_autobackup/ZfsAutobackup.py

@@ -2,6 +2,8 @@ import argparse
 import sys
 import time
 
+from zfs_autobackup import compressors
+from zfs_autobackup.ExecuteNode import ExecuteNode
 from zfs_autobackup.Thinner import Thinner
 from zfs_autobackup.ZfsDataset import ZfsDataset
 from zfs_autobackup.LogConsole import LogConsole
@@ -9,11 +11,13 @@ from zfs_autobackup.ZfsNode import ZfsNode
 from zfs_autobackup.ThinnerRule import ThinnerRule
 
 
+
+
 class ZfsAutobackup:
     """main class"""
 
-    VERSION = "3.1-beta4"
-    HEADER = "zfs-autobackup v{} - Copyright 2020 E.H.Eefting (edwin@datux.nl)".format(VERSION)
+    VERSION = "3.1-rc5"
+    HEADER = "zfs-autobackup v{} - (c)2021 E.H.Eefting (edwin@datux.nl)".format(VERSION)
 
     def __init__(self, argv, print_arguments=True):
 
@@ -41,6 +45,10 @@ class ZfsAutobackup:
                             help='Target ZFS filesystem (optional: if not specified, zfs-autobackup will only operate '
                                  'as snapshot-tool on source)')
 
+        parser.add_argument('--pre-snapshot-cmd', metavar="COMMAND", default=[], action='append',
+                            help='Run COMMAND before snapshotting (can be used multiple times.')
+        parser.add_argument('--post-snapshot-cmd', metavar="COMMAND", default=[], action='append',
+                            help='Run COMMAND after snapshotting (can be used multiple times.')
         parser.add_argument('--other-snapshots', action='store_true',
                             help='Send over other snapshots as well, not just the ones created by this tool.')
         parser.add_argument('--no-snapshot', action='store_true',
@@ -59,7 +67,6 @@ class ZfsAutobackup:
                             help='Ignore datasets that seem to be replicated some other way. (No changes since '
                                  'lastest snapshot. Useful for proxmox HA replication)')
 
-        parser.add_argument('--resume', action='store_true', help=argparse.SUPPRESS)
         parser.add_argument('--strip-path', metavar='N', default=0, type=int,
                             help='Number of directories to strip from target path (use 1 when cloning zones between 2 '
                                  'SmartOS machines)')
@@ -72,7 +79,7 @@ class ZfsAutobackup:
         parser.add_argument('--clear-mountpoint', action='store_true',
                             help='Set property canmount=noauto for new datasets. (recommended, prevents mount '
                                  'conflicts. same as --set-properties canmount=noauto)')
-        parser.add_argument('--filter-properties', metavar='PROPERY,...', type=str,
+        parser.add_argument('--filter-properties', metavar='PROPERTY,...', type=str,
                             help='List of properties to "filter" when receiving filesystems. (you can still restore '
                                  'them with zfs inherit -S)')
         parser.add_argument('--set-properties', metavar='PROPERTY=VALUE,...', type=str,
@@ -89,8 +96,6 @@ class ZfsAutobackup:
         parser.add_argument('--ignore-transfer-errors', action='store_true',
                             help='Ignore transfer errors (still checks if received filesystem exists. useful for '
                                  'acltype errors)')
-        parser.add_argument('--raw', action='store_true',
-                            help=argparse.SUPPRESS)
 
         parser.add_argument('--decrypt', action='store_true',
                             help='Decrypt data before sending it over.')
@@ -98,6 +103,9 @@ class ZfsAutobackup:
         parser.add_argument('--encrypt', action='store_true',
                             help='Encrypt data after receiving it.')
 
+        parser.add_argument('--zfs-compressed', action='store_true',
+                            help='Transfer blocks that already have zfs-compression as-is.')
+
         parser.add_argument('--test', action='store_true',
                             help='dont change anything, just show what would be done (still does all read-only '
                                  'operations)')
@@ -108,13 +116,24 @@ class ZfsAutobackup:
                             help='Show zfs commands and their output/exit codes. (noisy)')
         parser.add_argument('--progress', action='store_true',
                             help='show zfs progress output. Enabled automaticly on ttys. (use --no-progress to disable)')
-        parser.add_argument('--no-progress', action='store_true', help=argparse.SUPPRESS)  # needed to workaround a zfs recv -v bug
+        parser.add_argument('--no-progress', action='store_true',
+                            help=argparse.SUPPRESS)  # needed to workaround a zfs recv -v bug
 
+        parser.add_argument('--resume', action='store_true', help=argparse.SUPPRESS)
+        parser.add_argument('--raw', action='store_true', help=argparse.SUPPRESS)
+        parser.add_argument('--exclude-received', action='store_true',
+                            help=argparse.SUPPRESS)  # probably never needed anymore
+
+        #these things all do stuff by piping zfs send/recv IO
         parser.add_argument('--send-pipe', metavar="COMMAND", default=[], action='append',
-                            help='pipe zfs send output through COMMAND')
-
+                            help='pipe zfs send output through COMMAND (can be used multiple times)')
         parser.add_argument('--recv-pipe', metavar="COMMAND", default=[], action='append',
-                            help='pipe zfs recv input through COMMAND')
+                            help='pipe zfs recv input through COMMAND (can be used multiple times)')
+        parser.add_argument('--compress', metavar='TYPE', default=None, choices=compressors.choices(), help='Use compression during transfer, zstd-fast recommended. ({})'.format(", ".join(compressors.choices())))
+        parser.add_argument('--rate', metavar='DATARATE', default=None, help='Limit data transfer rate (e.g. 128K. requires mbuffer.)')
+        parser.add_argument('--buffer', metavar='SIZE', default=None, help='Add zfs send and recv buffers to smooth out IO bursts. (e.g. 128M. requires mbuffer)')
+
+
 
         # note args is the only global variable we use, since its a global readonly setting anyway
         args = parser.parse_args(argv)
@@ -138,20 +157,31 @@ class ZfsAutobackup:
             args.rollback = True
 
         self.log = LogConsole(show_debug=self.args.debug, show_verbose=self.args.verbose, color=sys.stdout.isatty())
+        self.verbose(self.HEADER)
 
         if args.resume:
-            self.verbose("NOTE: The --resume option isn't needed anymore (its autodetected now)")
+            self.warning("The --resume option isn't needed anymore (its autodetected now)")
 
         if args.raw:
-            self.verbose("NOTE: The --raw option isn't needed anymore (its autodetected now). Use --decrypt to explicitly send data decrypted.")
+            self.warning(
+                "The --raw option isn't needed anymore (its autodetected now). Also see --encrypt and --decrypt.")
 
         if args.target_path is not None and args.target_path[0] == "/":
             self.log.error("Target should not start with a /")
             sys.exit(255)
 
+        if args.compress and args.ssh_source is None and args.ssh_target is None:
+            self.warning("Using compression, but transfer is local.")
+
+        if args.compress and args.zfs_compressed:
+            self.warning("Using --compress with --zfs-compressed, might be inefficient.")
+
     def verbose(self, txt):
         self.log.verbose(txt)
 
+    def warning(self, txt):
+        self.log.warning(txt)
+
     def error(self, txt):
         self.log.error(txt)
 
@@ -162,31 +192,54 @@ class ZfsAutobackup:
         self.log.verbose("")
         self.log.verbose("#### " + title)
 
+    def progress(self, txt):
+        self.log.progress(txt)
+
+    def clear_progress(self):
+        self.log.clear_progress()
+
     # NOTE: this method also uses self.args. args that need extra processing are passed as function parameters:
     def thin_missing_targets(self, target_dataset, used_target_datasets):
         """thin target datasets that are missing on the source."""
 
         self.debug("Thinning obsolete datasets")
+        missing_datasets = [dataset for dataset in target_dataset.recursive_datasets if
+                            dataset not in used_target_datasets]
+
+        count = 0
+        for dataset in missing_datasets:
+
+            count = count + 1
+            if self.args.progress:
+                self.progress("Analysing missing {}/{}".format(count, len(missing_datasets)))
 
-        for dataset in target_dataset.recursive_datasets:
             try:
-                if dataset not in used_target_datasets:
                 dataset.debug("Missing on source, thinning")
                 dataset.thin()
 
             except Exception as e:
                 dataset.error("Error during thinning of missing datasets ({})".format(str(e)))
 
+        if self.args.progress:
+            self.clear_progress()
+
     # NOTE: this method also uses self.args. args that need extra processing are passed as function parameters:
     def destroy_missing_targets(self, target_dataset, used_target_datasets):
         """destroy target datasets that are missing on the source and that meet the requirements"""
 
         self.debug("Destroying obsolete datasets")
 
-        for dataset in target_dataset.recursive_datasets:
-            try:
-                if dataset not in used_target_datasets:
+        missing_datasets = [dataset for dataset in target_dataset.recursive_datasets if
+                            dataset not in used_target_datasets]
 
+        count = 0
+        for dataset in missing_datasets:
+
+            count = count + 1
+            if self.args.progress:
+                self.progress("Analysing destroy missing {}/{}".format(count, len(missing_datasets)))
+
+            try:
                 # cant do anything without our own snapshots
                 if not dataset.our_snapshots:
                     if dataset.datasets:
@@ -229,6 +282,66 @@ class ZfsAutobackup:
             except Exception as e:
                 dataset.error("Error during --destroy-missing: {}".format(str(e)))
 
+        if self.args.progress:
+            self.clear_progress()
+
+    def get_send_pipes(self, logger):
+        """determine the zfs send pipe"""
+
+        ret=[]
+
+        # IO buffer
+        if self.args.buffer:
+            logger("zfs send buffer        : {}".format(self.args.buffer))
+            ret.extend([ ExecuteNode.PIPE, "mbuffer", "-q", "-s128k", "-m"+self.args.buffer ])
+
+        # custom pipes
+        for send_pipe in self.args.send_pipe:
+            ret.append(ExecuteNode.PIPE)
+            ret.extend(send_pipe.split(" "))
+            logger("zfs send custom pipe   : {}".format(send_pipe))
+
+        # compression
+        if self.args.compress!=None:
+            ret.append(ExecuteNode.PIPE)
+            cmd=compressors.compress_cmd(self.args.compress)
+            ret.extend(cmd)
+            logger("zfs send compression   : {}".format(" ".join(cmd)))
+
+        # transfer rate
+        if self.args.rate:
+            logger("zfs send transfer rate : {}".format(self.args.rate))
+            ret.extend([ ExecuteNode.PIPE, "mbuffer", "-q", "-s128k", "-m16M", "-R"+self.args.rate ])
+
+
+        return ret
+
+    def get_recv_pipes(self, logger):
+
+        ret=[]
+
+        # decompression
+        if self.args.compress!=None:
+            cmd=compressors.decompress_cmd(self.args.compress)
+            ret.extend(cmd)
+            ret.append(ExecuteNode.PIPE)
+            logger("zfs recv decompression : {}".format(" ".join(cmd)))
+
+        # custom pipes
+        for recv_pipe in self.args.recv_pipe:
+            ret.extend(recv_pipe.split(" "))
+            ret.append(ExecuteNode.PIPE)
+            logger("zfs recv custom pipe   : {}".format(recv_pipe))
+
+        # IO buffer
+        if self.args.buffer:
+            #only add second buffer if its usefull. (e.g. non local transfer or other pipes active)
+            if self.args.ssh_source!=None or self.args.ssh_target!=None or self.args.recv_pipe or self.args.send_pipe or self.args.compress!=None:
+                logger("zfs recv buffer        : {}".format(self.args.buffer))
+                ret.extend(["mbuffer", "-q", "-s128k", "-m"+self.args.buffer,  ExecuteNode.PIPE ])
+
+        return ret
+
     # NOTE: this method also uses self.args. args that need extra processing are passed as function parameters:
     def sync_datasets(self, source_node, source_datasets, target_node):
         """Sync datasets, or thin-only on both sides
@@ -237,10 +350,19 @@ class ZfsAutobackup:
         :type source_node: ZfsNode
         """
 
+        send_pipes=self.get_send_pipes(source_node.verbose)
+        recv_pipes=self.get_recv_pipes(target_node.verbose)
+
         fail_count = 0
+        count = 0
         target_datasets = []
         for source_dataset in source_datasets:
 
+            # stats
+            if self.args.progress:
+                count = count + 1
+                self.progress("Analysing dataset {}/{} ({} failed)".format(count, len(source_datasets), fail_count))
+
             try:
                 # determine corresponding target_dataset
                 target_name = self.args.target_path + "/" + source_dataset.lstrip_path(self.args.strip_path)
@@ -268,14 +390,19 @@ class ZfsAutobackup:
                                               also_other_snapshots=self.args.other_snapshots,
                                               no_send=self.args.no_send,
                                               destroy_incompatible=self.args.destroy_incompatible,
-                                              output_pipes=self.args.send_pipe, input_pipes=self.args.recv_pipe, decrypt=self.args.decrypt, encrypt=self.args.encrypt)
+                                              send_pipes=send_pipes, recv_pipes=recv_pipes,
+                                              decrypt=self.args.decrypt, encrypt=self.args.encrypt, zfs_compressed=self.args.zfs_compressed )
             except Exception as e:
                 fail_count = fail_count + 1
                 source_dataset.error("FAILED: " + str(e))
                 if self.args.debug:
                     raise
 
+        if self.args.progress:
+            self.clear_progress()
+
         target_path_dataset = ZfsDataset(target_node, self.args.target_path)
+        if not self.args.no_thinning:
             self.thin_missing_targets(target_dataset=target_path_dataset, used_target_datasets=target_datasets)
 
         if self.args.destroy_missing is not None:
@@ -285,7 +412,6 @@ class ZfsAutobackup:
 
     def thin_source(self, source_datasets):
 
-        if not self.args.no_thinning:
         self.set_title("Thinning source")
 
         for source_dataset in source_datasets:
@@ -332,11 +458,11 @@ class ZfsAutobackup:
     def run(self):
 
         try:
-            self.verbose(self.HEADER)
 
             if self.args.test:
-                self.verbose("TEST MODE - SIMULATING WITHOUT MAKING ANY CHANGES")
+                self.warning("TEST MODE - SIMULATING WITHOUT MAKING ANY CHANGES")
 
+            ################ create source zfsNode
             self.set_title("Source settings")
 
             description = "[Source]"
@@ -348,12 +474,28 @@ class ZfsAutobackup:
                                   ssh_to=self.args.ssh_source, readonly=self.args.test,
                                   debug_output=self.args.debug_output, description=description, thinner=source_thinner)
             source_node.verbose(
-                "Selects all datasets that have property 'autobackup:{}=true' (or childs of datasets that have "
+                "Selects all datasets that have property 'autobackup:{}=true' (or children of datasets that have "
                 "'autobackup:{}=child')".format(
                     self.args.backup_name, self.args.backup_name))
 
+            ################# select source datasets
             self.set_title("Selecting")
-            selected_source_datasets = source_node.selected_datasets
+
+            #Note: Before version v3.1-beta5, we always used exclude_received. This was a problem if you wanto to replicate an existing backup to another host and use the same backupname/snapshots.
+            exclude_paths = []
+            exclude_received=self.args.exclude_received
+            if self.args.ssh_source == self.args.ssh_target:
+                if self.args.target_path:
+                    # target and source are the same, make sure to exclude target_path
+                    self.warning("Source and target are on the same host, excluding target-path from selection.")
+                    exclude_paths.append(self.args.target_path)
+                else:
+                    self.warning("Source and target are on the same host, excluding received datasets from selection.")
+                    exclude_received=True
+
+
+            selected_source_datasets = source_node.selected_datasets(exclude_received=exclude_received,
+                                                                     exclude_paths=exclude_paths)
             if not selected_source_datasets:
                 self.error(
                     "No source filesystems selected, please do a 'zfs set autobackup:{0}=true' on the source datasets "
@@ -364,11 +506,15 @@ class ZfsAutobackup:
             # filter out already replicated stuff?
             source_datasets = self.filter_replicated(selected_source_datasets)
 
+            ################# snapshotting
             if not self.args.no_snapshot:
                 self.set_title("Snapshotting")
                 source_node.consistent_snapshot(source_datasets, source_node.new_snapshotname(),
-                                                min_changed_bytes=self.args.min_change)
+                                                min_changed_bytes=self.args.min_change,
+                                                pre_snapshot_cmds=self.args.pre_snapshot_cmd,
+                                                post_snapshot_cmds=self.args.post_snapshot_cmd)
 
+            ################# sync
             # if target is specified, we sync the datasets, otherwise we just thin the source. (e.g. snapshot mode)
             if self.args.target_path:
 
@@ -402,6 +548,7 @@ class ZfsAutobackup:
 
             # no target specified, run in snapshot-only mode
             else:
+                if not self.args.no_thinning:
                     self.thin_source(source_datasets)
                 fail_count = 0
 
@@ -419,7 +566,7 @@ class ZfsAutobackup:
 
             if self.args.test:
                 self.verbose("")
-                self.verbose("TEST MODE - DID NOT MAKE ANY CHANGES!")
+                self.warning("TEST MODE - DID NOT MAKE ANY CHANGES!")
 
             return fail_count
 

zfs_autobackup/ZfsDataset.py

@@ -1,5 +1,4 @@
 import re
-import subprocess
 import time
 
 from zfs_autobackup.CachedProperty import CachedProperty
@@ -113,15 +112,16 @@ class ZfsDataset:
         """true if this dataset is a snapshot"""
         return self.name.find("@") != -1
 
-    def is_selected(self, value, source, inherited, ignore_received):
+    def is_selected(self, value, source, inherited, exclude_received, exclude_paths):
         """determine if dataset should be selected for backup (called from
         ZfsNode)
 
         Args:
+            :type exclude_paths: list of str
             :type value: str
             :type source: str
             :type inherited: bool
-            :type ignore_received: bool
+            :type exclude_received: bool
         """
 
         # sanity checks
@@ -129,22 +129,30 @@ class ZfsDataset:
             # probably a program error in zfs-autobackup or new feature in zfs
             raise (Exception(
                 "{} autobackup-property has illegal source: '{}' (possible BUG)".format(self.name, source)))
+
         if value not in ["false", "true", "child", "-"]:
             # user error
             raise (Exception(
                 "{} autobackup-property has illegal value: '{}'".format(self.name, value)))
 
+        # our path starts with one of the excluded paths?
+        for exclude_path in exclude_paths:
+            if self.name.startswith(exclude_path):
+                # too noisy for verbose
+                self.debug("Excluded (in exclude list)")
+                return False
+
         # now determine if its actually selected
         if value == "false":
-            self.verbose("Ignored (disabled)")
+            self.verbose("Excluded (disabled)")
             return False
         elif value == "true" or (value == "child" and inherited):
             if source == "local":
                 self.verbose("Selected")
                 return True
             elif source == "received":
-                if ignore_received:
-                    self.verbose("Ignored (local backup)")
+                if exclude_received:
+                    self.verbose("Excluded (dataset already received)")
                     return False
                 else:
                     self.verbose("Selected")
@@ -495,14 +503,15 @@ class ZfsDataset:
 
         return self.from_names(names[1:])
 
-    def send_pipe(self, features, prev_snapshot, resume_token, show_progress, raw, send_properties, write_embedded, output_pipes):
+    def send_pipe(self, features, prev_snapshot, resume_token, show_progress, raw, send_properties, write_embedded, send_pipes, zfs_compressed):
         """returns a pipe with zfs send output for this snapshot
 
         resume_token: resume sending from this token. (in that case we don't
         need to know snapshot names)
 
         Args:
-            :type output_pipes: list of str
+            :param send_pipes: output cmd array that will be added to actual zfs send command. (e.g. mbuffer or compression program)
+            :type send_pipes: list of str
             :type features: list of str
             :type prev_snapshot: ZfsDataset
             :type resume_token: str
@@ -521,7 +530,7 @@ class ZfsDataset:
         if write_embedded and 'embedded_data' in features and "-e" in self.zfs_node.supported_send_options:
             cmd.append("--embed")  # WRITE_EMBEDDED, more compact stream
 
-        if "-c" in self.zfs_node.supported_send_options:
+        if zfs_compressed and "-c" in self.zfs_node.supported_send_options:
             cmd.append("--compressed")  # use compressed WRITE records
 
         # raw? (send over encrypted data in its original encrypted form without decrypting)
@@ -548,24 +557,13 @@ class ZfsDataset:
 
             cmd.append(self.name)
 
-        # #add custom output pipes?
-        # if output_pipes:
-        #     #local so do our own piping
-        #     if self.zfs_node.is_local():
-        #         output_pipe = self.zfs_node.run(cmd)
-        #         for pipe_cmd in output_pipes:
-        #             output_pipe=self.zfs_node.run(pipe_cmd, inp=output_pipe, )
-        #         return output_pipe
-        #     #remote, so add with actual | and let remote shell handle it
-        #     else:
-        #         for pipe_cmd in output_pipes:
-        #             cmd.append("|")
-        #             cmd.extend(pipe_cmd)
+        cmd.extend(send_pipes)
 
-        return self.zfs_node.run(cmd, pipe=True, readonly=True)
+        output_pipe = self.zfs_node.run(cmd, pipe=True, readonly=True)
 
+        return output_pipe
 
-    def recv_pipe(self, pipe, features, filter_properties=None, set_properties=None, ignore_exit_code=False):
+    def recv_pipe(self, pipe, features, recv_pipes, filter_properties=None, set_properties=None, ignore_exit_code=False):
         """starts a zfs recv for this snapshot and uses pipe as input
 
         note: you can it both on a snapshot or filesystem object. The
@@ -573,6 +571,7 @@ class ZfsDataset:
         differently.
 
         Args:
+            :param recv_pipes: input cmd array that will be prepended to actual zfs recv command. (e.g. mbuffer or decompression program)
             :type pipe: subprocess.pOpen
             :type features: list of str
             :type filter_properties: list of str
@@ -589,6 +588,8 @@ class ZfsDataset:
         # build target command
         cmd = []
 
+        cmd.extend(recv_pipes)
+
         cmd.extend(["zfs", "recv"])
 
         # don't mount filesystem that is received
@@ -633,15 +634,15 @@ class ZfsDataset:
 
     def transfer_snapshot(self, target_snapshot, features, prev_snapshot, show_progress,
                           filter_properties, set_properties, ignore_recv_exit_code, resume_token,
-                          raw, send_properties, write_embedded, output_pipes, input_pipes):
+                          raw, send_properties, write_embedded, send_pipes, recv_pipes, zfs_compressed):
         """transfer this snapshot to target_snapshot. specify prev_snapshot for
         incremental transfer
 
         connects a send_pipe() to recv_pipe()
 
         Args:
-            :type output_pipes: list of str
-            :type input_pipes: list of str
+            :type send_pipes: list of str
+            :type recv_pipes: list of str
             :type target_snapshot: ZfsDataset
             :type features: list of str
             :type prev_snapshot: ZfsDataset
@@ -672,12 +673,13 @@ class ZfsDataset:
 
         # do it
         pipe = self.send_pipe(features=features, show_progress=show_progress, prev_snapshot=prev_snapshot,
-                              resume_token=resume_token, raw=raw, send_properties=send_properties, write_embedded=write_embedded, output_pipes=output_pipes)
+                              resume_token=resume_token, raw=raw, send_properties=send_properties, write_embedded=write_embedded, send_pipes=send_pipes, zfs_compressed=zfs_compressed)
         target_snapshot.recv_pipe(pipe, features=features, filter_properties=filter_properties,
-                                  set_properties=set_properties, ignore_exit_code=ignore_recv_exit_code)
+                                  set_properties=set_properties, ignore_exit_code=ignore_recv_exit_code, recv_pipes=recv_pipes)
 
     def abort_resume(self):
         """abort current resume state"""
+        self.debug("Aborting resume")
         self.zfs_node.run(["zfs", "recv", "-A", self.name])
 
     def rollback(self):
@@ -872,9 +874,13 @@ class ZfsDataset:
             :type target_keeps: list of ZfsDataset
         """
 
-        # on source: destroy all obsoletes before common.
+        # on source: destroy all obsoletes before common. (since we cant send them anyways)
         # But after common, only delete snapshots that target also doesn't want
+        if common_snapshot:
             before_common = True
+        else:
+            before_common = False
+
         for source_snapshot in self.snapshots:
             if common_snapshot and source_snapshot.snapshot_name == common_snapshot.snapshot_name:
                 before_common = False
@@ -886,8 +892,8 @@ class ZfsDataset:
 
         # on target: destroy everything thats obsolete, except common_snapshot
         for target_snapshot in target_dataset.snapshots:
-            if (target_snapshot in target_obsoletes) and (
-                    not common_snapshot or target_snapshot.snapshot_name != common_snapshot.snapshot_name):
+            if (target_snapshot in target_obsoletes) \
+                    and ( not common_snapshot or (target_snapshot.snapshot_name != common_snapshot.snapshot_name)):
                 if target_snapshot.exists:
                     target_snapshot.destroy()
 
@@ -900,11 +906,15 @@ class ZfsDataset:
         """
 
         if 'receive_resume_token' in target_dataset.properties:
+            if start_snapshot==None:
+                target_dataset.verbose("Aborting resume, its obsolete.")
+                target_dataset.abort_resume()
+            else:
                 resume_token = target_dataset.properties['receive_resume_token']
-            # not valid anymore?
+                # not valid anymore
                 resume_snapshot = self.get_resume_snapshot(resume_token)
                 if not resume_snapshot or start_snapshot.snapshot_name != resume_snapshot.snapshot_name:
-                target_dataset.verbose("Cant resume, resume token no longer valid.")
+                    target_dataset.verbose("Aborting resume, its no longer valid.")
                     target_dataset.abort_resume()
                 else:
                     return resume_token
@@ -962,13 +972,13 @@ class ZfsDataset:
 
     def sync_snapshots(self, target_dataset, features, show_progress, filter_properties, set_properties,
                        ignore_recv_exit_code, holds, rollback, decrypt, encrypt, also_other_snapshots,
-                       no_send, destroy_incompatible, output_pipes, input_pipes):
+                       no_send, destroy_incompatible, send_pipes, recv_pipes, zfs_compressed):
         """sync this dataset's snapshots to target_dataset, while also thinning
         out old snapshots along the way.
 
         Args:
-            :type output_pipes: list of str
-            :type input_pipes: list of str
+            :type send_pipes: list of str
+            :type recv_pipes: list of str
             :type target_dataset: ZfsDataset
             :type features: list of str
             :type show_progress: bool
@@ -977,7 +987,6 @@ class ZfsDataset:
             :type ignore_recv_exit_code: bool
             :type holds: bool
             :type rollback: bool
-            :type raw: bool
             :type decrypt: bool
             :type also_other_snapshots: bool
             :type no_send: bool
@@ -1046,7 +1055,7 @@ class ZfsDataset:
                                                   filter_properties=active_filter_properties,
                                                   set_properties=active_set_properties,
                                                   ignore_recv_exit_code=ignore_recv_exit_code,
-                                                  resume_token=resume_token, write_embedded=write_embedded,raw=raw, send_properties=send_properties, output_pipes=output_pipes, input_pipes=input_pipes)
+                                                  resume_token=resume_token, write_embedded=write_embedded, raw=raw, send_properties=send_properties, send_pipes=send_pipes, recv_pipes=recv_pipes, zfs_compressed=zfs_compressed)
 
                 resume_token = None
 
@@ -1075,7 +1084,7 @@ class ZfsDataset:
                 source_snapshot.debug("skipped (target doesn't need it)")
                 # was it actually a resume?
                 if resume_token:
-                    target_dataset.debug("aborting resume, since we don't want that snapshot anymore")
+                    target_dataset.verbose("Aborting resume, we dont want that snapshot anymore.")
                     target_dataset.abort_resume()
                     resume_token = None
 

zfs_autobackup/ZfsNode.py

@@ -1,6 +1,7 @@
 # python 2 compatibility
 from __future__ import print_function
 import re
+import shlex
 import subprocess
 import sys
 import time
@@ -120,7 +121,7 @@ class ZfsNode(ExecuteNode):
                     self._progress_total_bytes = int(progress_fields[2])
                 elif progress_fields[0] == 'incremental':
                     self._progress_total_bytes = int(progress_fields[3])
-                else:
+                elif progress_fields[1].isnumeric():
                     bytes_ = int(progress_fields[1])
                     if self._progress_total_bytes:
                         percentage = min(100, int(bytes_ * 100 / self._progress_total_bytes))
@@ -128,9 +129,8 @@ class ZfsNode(ExecuteNode):
                         bytes_left = self._progress_total_bytes - bytes_
                         minutes_left = int((bytes_left / (bytes_ / (time.time() - self._progress_start_time))) / 60)
 
-                        print(">>> {}% {}MB/s (total {}MB, {} minutes left)     \r".format(percentage, speed, int(
-                            self._progress_total_bytes / (1024 * 1024)), minutes_left), end='', file=sys.stderr)
-                        sys.stderr.flush()
+                        self.logger.progress("Transfer {}% {}MB/s (total {}MB, {} minutes left)".format(percentage, speed, int(
+                            self._progress_total_bytes / (1024 * 1024)), minutes_left))
 
             return
 
@@ -152,6 +152,9 @@ class ZfsNode(ExecuteNode):
     def error(self, txt):
         self.logger.error("{} {}".format(self.description, txt))
 
+    def warning(self, txt):
+        self.logger.warning("{} {}".format(self.description, txt))
+
     def debug(self, txt):
         self.logger.debug("{} {}".format(self.description, txt))
 
@@ -159,7 +162,7 @@ class ZfsNode(ExecuteNode):
         """determine uniq new snapshotname"""
         return self.backup_name + "-" + time.strftime("%Y%m%d%H%M%S")
 
-    def consistent_snapshot(self, datasets, snapshot_name, min_changed_bytes):
+    def consistent_snapshot(self, datasets, snapshot_name, min_changed_bytes, pre_snapshot_cmds=[], post_snapshot_cmds=[]):
         """create a consistent (atomic) snapshot of specified datasets, per pool.
         """
 
@@ -189,6 +192,11 @@ class ZfsNode(ExecuteNode):
             self.verbose("No changes anywhere: not creating snapshots.")
             return
 
+        try:
+            for cmd in pre_snapshot_cmds:
+                self.verbose("Running pre-snapshot-cmd")
+                self.run(cmd=shlex.split(cmd), readonly=False)
+
             # create consistent snapshot per pool
             for (pool_name, snapshots) in pools.items():
                 cmd = ["zfs", "snapshot"]
@@ -198,9 +206,18 @@ class ZfsNode(ExecuteNode):
                 self.verbose("Creating snapshots {} in pool {}".format(snapshot_name, pool_name))
                 self.run(cmd, readonly=False)
 
-    @CachedProperty
-    def selected_datasets(self, ignore_received=True):
-        """determine filesystems that should be backupped by looking at the special autobackup-property, systemwide
+        finally:
+            for cmd in post_snapshot_cmds:
+                self.verbose("Running post-snapshot-cmd")
+                try:
+                    self.run(cmd=shlex.split(cmd), readonly=False)
+                except Exception as e:
+                    pass
+
+
+
+    def selected_datasets(self, exclude_received, exclude_paths):
+        """determine filesystems that should be backed up by looking at the special autobackup-property, systemwide
 
            returns: list of ZfsDataset
         """
@@ -234,7 +251,7 @@ class ZfsNode(ExecuteNode):
                 source = raw_source
 
             # determine it
-            if dataset.is_selected(value=value, source=source, inherited=inherited, ignore_received=ignore_received):
+            if dataset.is_selected(value=value, source=source, inherited=inherited, exclude_received=exclude_received, exclude_paths=exclude_paths):
                 selected_filesystems.append(dataset)
 
         return selected_filesystems

zfs_autobackup/compressors.py

@@ -0,0 +1,69 @@
+# Adopted from Syncoid :)
+
+# this software is licensed for use under the Free Software Foundation's GPL v3.0 license, as retrieved
+# from http://www.gnu.org/licenses/gpl-3.0.html on 2014-11-17.  A copy should also be available in this
+# project's Git repository at https://github.com/jimsalterjrs/sanoid/blob/master/LICENSE.
+
+COMPRESS_CMDS = {
+    'gzip': {
+        'cmd': 'gzip',
+        'args': [ '-3' ],
+        'dcmd': 'zcat',
+        'dargs': [],
+    },
+    'pigz-fast': {
+        'cmd': 'pigz',
+        'args': [ '-3' ],
+        'dcmd': 'pigz',
+        'dargs': [ '-dc' ],
+    },
+    'pigz-slow': {
+        'cmd': 'pigz',
+        'args': [ '-9' ],
+        'dcmd': 'pigz',
+        'dargs': [ '-dc' ],
+    },
+    'zstd-fast': {
+        'cmd': 'zstdmt',
+        'args': [ '-3' ],
+        'dcmd': 'zstdmt',
+        'dargs': [ '-dc' ],
+    },
+    'zstd-slow': {
+        'cmd': 'zstdmt',
+        'args': [ '-19' ],
+        'dcmd': 'zstdmt',
+        'dargs': [ '-dc' ],
+    },
+    'xz': {
+        'cmd': 'xz',
+        'args': [],
+        'dcmd': 'xz',
+        'dargs': [ '-d' ],
+    },
+    'lzo': {
+        'cmd': 'lzop',
+        'args': [],
+        'dcmd': 'lzop',
+        'dargs': [ '-dfc' ],
+    },
+    'lz4': {
+        'cmd': 'lz4',
+        'args': [],
+        'dcmd': 'lz4',
+        'dargs': [ '-dc' ],
+    },
+}
+
+def compress_cmd(compressor):
+    ret=[ COMPRESS_CMDS[compressor]['cmd'] ]
+    ret.extend( COMPRESS_CMDS[compressor]['args'])
+    return ret
+
+def decompress_cmd(compressor):
+    ret= [ COMPRESS_CMDS[compressor]['dcmd'] ]
+    ret.extend(COMPRESS_CMDS[compressor]['dargs'])
+    return ret
+
+def choices():
+    return COMPRESS_CMDS.keys()