mirror of
https://github.com/psy0rz/zfs_autobackup.git
synced 2025-04-11 22:40:01 +03:00
378 lines
14 KiB
Python
Executable File
378 lines
14 KiB
Python
Executable File
#!/usr/bin/env python
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# -*- coding: utf8 -*-
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from __future__ import print_function
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import os
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import sys
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import re
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import traceback
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import subprocess
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import pprint
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import cStringIO
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import time
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###### parse arguments
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import argparse
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parser = argparse.ArgumentParser(description='ZFS autobackup v2.0')
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parser.add_argument('--ssh-source', default="local", help='Source host to get backup from. (user@hostname) Default %(default)s.')
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parser.add_argument('--ssh-target', default="local", help='Target host to push backup to. (user@hostname) Default %(default)s.')
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parser.add_argument('--ssh-cipher', default="arcfour128", help='SSH cipher to use (default %(default)s)')
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parser.add_argument('--keep-source', default=30, help='Number of old snapshots to keep on source. Default %(default)s.')
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parser.add_argument('--keep-target', default=30, help='Number of old snapshots to keep on target. Default %(default)s.')
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parser.add_argument('backup_name', help='Name of the backup (you should set the zfs property "autobackup:backup-name" to true on filesystems you want to backup')
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parser.add_argument('target_fs', help='Target filesystem')
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parser.add_argument('--finish', action='store_true', help='dont create new snapshot, just finish sending current snapshots')
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parser.add_argument('--compress', action='store_true', help='use compression during zfs send/recv')
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parser.add_argument('--test', action='store_true', help='dont change anything, just show what would be done (still does all read-only operations)')
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parser.add_argument('--verbose', action='store_true', help='verbose output')
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parser.add_argument('--debug', action='store_true', help='debug output (shows user details, decicions that are made and commands that are executed)')
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args = parser.parse_args()
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def error(txt):
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print(txt, file=sys.stderr)
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def verbose(txt):
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if args.verbose:
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print(txt)
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def debug(txt):
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if args.debug:
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print(txt)
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"""run a command. specifiy ssh user@host to run remotely"""
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def run(cmd, input=None, ssh_to="local", tab_split=False, valid_exitcodes=[ 0 ], test=False):
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encoded_cmd=[]
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#use ssh?
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if ssh_to != "local":
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encoded_cmd.extend(["ssh", "-c", args.ssh_cipher, ssh_to])
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if args.compress:
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encoded_cmd.append("-C")
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#make sure the command gets all the data in utf8 format:
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#(this is neccesary if LC_ALL=en_US.utf8 is not set in the environment)
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for arg in cmd:
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encoded_cmd.append(arg.encode('utf-8'))
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#the accurate way of displaying it whould be: print encoded_cmd
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#However, we use the more human-readable way, but this is not always properly escaped!
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#(most of the time it should be copypastable however.)
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debug_txt="# "+encoded_cmd[0]+" '"+("' '".join(encoded_cmd[1:]))+"'"
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if test:
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debug("[TEST] "+debug_txt)
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else:
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debug(debug_txt)
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if input:
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debug("INPUT:\n"+input.rstrip())
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stdin=subprocess.PIPE
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else:
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stdin=None
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if test:
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return
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p=subprocess.Popen(encoded_cmd, env=os.environ, stdout=subprocess.PIPE, stdin=stdin)
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output=p.communicate(input=input)[0]
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if p.returncode not in valid_exitcodes:
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raise(subprocess.CalledProcessError(p.returncode, encoded_cmd))
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lines=output.splitlines()
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if not tab_split:
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return(lines)
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else:
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ret=[]
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for line in lines:
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ret.append(line.split("\t"))
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return(ret)
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"""determine filesystems that should be backupped by looking at the special autobackup-property"""
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def zfs_get_selected_filesystems(ssh_to, backup_name):
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#get all source filesystems that have the backup property
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source_filesystems=run(ssh_to=ssh_to, tab_split=True, cmd=[
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"zfs", "get", "-t", "volume,filesystem", "-o", "name,value,source", "-s", "local,inherited", "-H", "autobackup:"+backup_name
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])
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#determine filesystems that should be actually backupped
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selected_filesystems=[]
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direct_filesystems=[]
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for source_filesystem in source_filesystems:
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(name,value,source)=source_filesystem
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if value=="false":
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verbose("Ignoring: {0} (disabled)".format(name))
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else:
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if source=="local":
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selected_filesystems.append(name)
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direct_filesystems.append(name)
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verbose("Selected: {0} (direct selection)".format(name))
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elif source.find("inherited from ")==0:
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inherited_from=re.sub("^inherited from ", "", source)
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if inherited_from in direct_filesystems:
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selected_filesystems.append(name)
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verbose("Selected: {0} (inherited selection)".format(name))
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else:
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verbose("Ignored: {0} (already a backup)".format(name))
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else:
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vebose("Ignored: {0} ({0})".format(source))
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return(selected_filesystems)
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"""destroy list of filesystems or snapshots"""
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def zfs_destroy(ssh_to, filesystems):
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debug("Destroying on {0}:\n{1}".format(ssh_to, "\n".join(filesystems)))
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#zfs can only destroy one filesystem at once so we use xargs and stdin
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run(ssh_to=ssh_to, test=args.test, input="\0".join(filesystems), cmd=
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[ "xargs", "-0", "-n", "1", "zfs", "destroy", "-d" ]
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)
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#simulate snapshots for --test option
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test_snapshots={}
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"""create snapshot on multiple filesystems at once (atomicly)"""
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def zfs_create_snapshot(ssh_to, filesystems, snapshot):
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cmd=[ "zfs", "snapshot" ]
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for filesystem in filesystems:
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cmd.append(filesystem+"@"+snapshot)
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#in testmode we dont actually make changes, so keep them in a list to simulate
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if args.test:
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if not ssh_to in test_snapshots:
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test_snapshots[ssh_to]={}
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if not filesystem in test_snapshots[ssh_to]:
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test_snapshots[ssh_to][filesystem]=[]
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test_snapshots[ssh_to][filesystem].append(snapshot)
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run(ssh_to=ssh_to, tab_split=False, cmd=cmd, test=args.test)
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"""get names of all snapshots for specified filesystems belonging to backup_name
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return[filesystem_name]=[ "snashot1", "snapshot2", ... ]
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"""
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def zfs_get_snapshots(ssh_to, filesystems, backup_name):
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cmd=[
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"zfs", "list", "-d", "1", "-r", "-t" ,"snapshot", "-H", "-o", "name"
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]
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cmd.extend(filesystems)
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snapshots=run(ssh_to=ssh_to, tab_split=False, cmd=cmd, valid_exitcodes=[ 0,1 ])
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ret={}
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for snapshot in snapshots:
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(filesystem, snapshot_name)=snapshot.split("@")
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if re.match("^"+backup_name+"-[0-9]*$", snapshot_name):
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if not filesystem in ret:
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ret[filesystem]=[]
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ret[filesystem].append(snapshot_name)
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#also add any test-snapshots that where created with --test mode
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if args.test:
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if ssh_to in test_snapshots:
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for filesystem in filesystems:
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if filesystem in test_snapshots[ssh_to]:
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ret[filesystem].extend(test_snapshots[ssh_to][filesystem])
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return(ret)
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"""transfer a zfs snapshot from source to target. both can be either local or via ssh."""
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def zfs_transfer(ssh_source, source_filesystem, first_snapshot, second_snapshot,
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ssh_target, target_filesystem):
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#### build source command
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source_cmd=[]
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if ssh_source != "local":
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source_cmd.extend([ "ssh", "-c", args.ssh_cipher, ssh_source ])
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if args.compress:
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source_cmd.append("-C")
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source_cmd.extend(["zfs", "send", "-p" ])
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if args.verbose:
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source_cmd.append("-v")
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if not first_snapshot:
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verbose("Tranferring "+source_filesystem+" initial backup snapshot "+second_snapshot)
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else:
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verbose("Tranferring "+source_filesystem+" incremental backup between snapshots "+first_snapshot+"..."+second_snapshot)
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source_cmd.extend([ "-i", first_snapshot ])
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source_cmd.append(source_filesystem + "@" + second_snapshot)
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#### build target command
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target_cmd=[]
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if ssh_target != "local":
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target_cmd.extend([ "ssh", "-c", args.ssh_cipher, ssh_target ])
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if args.compress:
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target_cmd.append("-C")
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target_cmd.extend(["zfs", "recv", "-u" ])
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if args.verbose:
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target_cmd.append("-v")
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target_cmd.append(target_filesystem)
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#### make sure parent on target exists
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parent_filesystem= "/".join(target_filesystem.split("/")[:-1])
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run(ssh_to=ssh_target, cmd=[ "zfs", "create" ,"-p", parent_filesystem ], test=args.test)
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### execute pipe
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debug_txt="# "+source_cmd[0]+" '"+("' '".join(source_cmd[1:]))+"'" + " | " + target_cmd[0]+" '"+("' '".join(target_cmd[1:]))+"'"
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if args.test:
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debug("[TEST] "+debug_txt)
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return
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else:
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debug(debug_txt)
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source_proc=subprocess.Popen(source_cmd, env=os.environ, stdout=subprocess.PIPE)
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target_proc=subprocess.Popen(target_cmd, env=os.environ, stdin=source_proc.stdout)
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source_proc.stdout.close() # Allow p1 to receive a SIGPIPE if p2 exits.
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target_proc.communicate()
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if source_proc.returncode:
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raise(subprocess.CalledProcessError(source_proc.returncode, source_cmd))
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#zfs recv sometimes gives an exitcode 1 while the transfer was succesfull, therefore we ignore exit 1's and do an extra check to see if the snapshot is there.
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if target_proc.returncode and target_proc.returncode!=1:
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raise(subprocess.CalledProcessError(target_proc.returncode, target_cmd))
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debug("Verifying if snapshot exists on target")
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run(ssh_to=ssh_target, cmd=["zfs", "list", target_filesystem+"@"+second_snapshot ])
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################################################################## ENTRY POINT
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if args.test:
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args.verbose=True
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verbose("RUNNING IN TEST-MODE, NOT MAKING ACTUAL BACKUP!")
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if args.keep_source<1 or args.keep_target<1:
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raise(Exception("Minimum number of snapshots to keep is 1"))
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#get selected filesystem on backup source
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verbose("Getting selected source filesystems for backup {0} on {1}".format(args.backup_name,args.ssh_source))
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source_filesystems=zfs_get_selected_filesystems(args.ssh_source, args.backup_name)
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#nothing todo
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if not source_filesystems:
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error("No filesystems source selected, please set autobackup:{0} on {1}".format(args.backup_name,args.ssh_source))
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sys.exit(1)
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#determine target filesystems
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target_filesystems=[]
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for source_filesystem in source_filesystems:
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target_filesystems.append(args.target_fs+"/"+source_filesystem)
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#create new snapshot?
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if not args.finish:
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new_snapshot_name=args.backup_name+"-"+time.strftime("%Y%m%d%H%M%S")
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verbose("Creating source snapshot {0} on {1} ".format(new_snapshot_name, args.ssh_source))
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zfs_create_snapshot(args.ssh_source, source_filesystems, new_snapshot_name)
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#determine all snapshots of all selected filesystems on both source and target
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verbose("Getting source snapshot-list from {0}".format(args.ssh_source))
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source_snapshots=zfs_get_snapshots(args.ssh_source, source_filesystems, args.backup_name)
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debug("Source snapshots: " + str(pprint.pformat(source_snapshots)))
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target_snapshots={}
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try:
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verbose("Getting target snapshot-list from {0}".format(args.ssh_target))
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target_snapshots=zfs_get_snapshots(args.ssh_target, target_filesystems, args.backup_name)
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except subprocess.CalledProcessError:
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verbose("(ignoring errors, probably initial backup for this filesystem)")
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pass
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debug("Target snapshots: " + str(pprint.pformat(target_snapshots)))
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#determine which snapshots to send for each filesystem
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for source_filesystem in source_filesystems:
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target_filesystem=args.target_fs+"/"+source_filesystem
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if source_filesystem not in source_snapshots:
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#this happens if you use --finish and there are new filesystems without snapshots
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verbose("Skipping source filesystem {0}, no snapshots found".format(source_filesystem))
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else:
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send_snapshots=source_snapshots[source_filesystem][:]
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#remove snapshots that are already on target from send-list
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if target_filesystem in target_snapshots and target_snapshots[target_filesystem]:
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latest_target_snapshot=target_snapshots[target_filesystem][-1]
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if latest_target_snapshot not in send_snapshots:
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raise(Exception("Cant find latest target snapshot on source, did you destroy it accidently? "+source_filesystem+"@"+latest_target_snapshot))
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while latest_target_snapshot in send_snapshots:
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send_snapshots.pop(0)
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else:
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latest_target_snapshot=None
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#now actually send the snapshots
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for send_snapshot in send_snapshots:
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zfs_transfer(
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ssh_source=args.ssh_source, source_filesystem=source_filesystem, first_snapshot=latest_target_snapshot, second_snapshot=send_snapshot,
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ssh_target=args.ssh_target, target_filesystem=target_filesystem)
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#update target_snapshot list for later cleanup
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target_snapshots[target_filesystem].append(send_snapshot)
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latest_target_snapshot=send_snapshot
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#cleanup old source snapshots
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source_destroys=[]
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for source_filesystem in source_snapshots:
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destroy_count=len(source_snapshots[source_filesystem])-args.keep_source
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if destroy_count>0:
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for snapshot in source_snapshots[source_filesystem][0:destroy_count-1]:
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source_destroys.append(source_filesystem+"@"+snapshot)
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if source_destroys:
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verbose("Destroying old snapshots on source")
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zfs_destroy(ssh_to=args.ssh_source, filesystems=source_destroys)
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#cleanup old target snapshots
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target_destroys=[]
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for target_filesystem in target_snapshots:
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destroy_count=len(target_snapshots[target_filesystem])-args.keep_target
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if destroy_count>0:
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for snapshot in target_snapshots[target_filesystem][0:destroy_count-1]:
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target_destroys.append(target_filesystem+"@"+snapshot)
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if target_destroys:
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verbose("Destroying old snapshots on target")
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zfs_destroy(ssh_to=args.ssh_target, filesystems=target_destroys)
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verbose("All done")
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