initial commitHEADmaster

1 files changed, 140 insertions, 0 deletions

diff --git a/tarsnap-backup.py b/tarsnap-backup.py
new file mode 100755
index 0000000..e85617b
--- /dev/null
+++ b/tarsnap-backup.py
@@ -0,0 +1,140 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+from datetime import datetime
+import argparse
+import calendar
+import logging
+import os
+import re
+import shlex
+import StringIO
+import subprocess
+import sys
+
+class MyArgumentParser(argparse.ArgumentParser):
+    def __init__(self, *args, **kwargs):
+        super(MyArgumentParser, self).__init__(*args, **kwargs)
+
+    def convert_arg_line_to_args(self, line):
+        for arg in shlex.split(line, comments=True):
+            if not arg.strip():
+                continue
+            yield arg
+
+argparser = MyArgumentParser(fromfile_prefix_chars='@')
+argparser.add_argument('-v', '--verbose', action='count',
+    help='Produce verbose output (can be specified more than once)')
+argparser.add_argument('-n', '--dry-run', action='store_true',
+    help='Do not modify anything')
+argparser.add_argument('-d', '--dir', action='append', required=True,
+    help='Specify a directory to backup (can be given multiple times)')
+argparser.add_argument('--daily', type=int, default=7,
+    help='Number of daily backups to keep (default: 7)')
+argparser.add_argument('--weekly', type=int, default=4,
+    help='Number of weekly backups to keep (default: 4)')
+argparser.add_argument('--monthly', type=int, default=2,
+    help='Number of monthly backups to keep (default: 2)')
+argparser.add_argument('--weekly-day', type=int, default=0,
+    help='Which day to do weekly backups on (0=monday, 6=sunday)')
+argparser.add_argument('--monthly-day', type=int, default=1,
+    help='Which day to do monthly backups on (1-31)')
+
+cmdline_args = argparser.parse_args()
+
+if cmdline_args.verbose == 1:
+    loglevel = logging.INFO
+elif cmdline_args.verbose >= 2:
+    loglevel = logging.DEBUG
+else:
+    loglevel = logging.WARNING
+
+log = logging.getLogger(__name__)
+logging.basicConfig(format="%(asctime)s %(levelname)-8s %(message)s",
+    datefmt="%Y-%m-%d %H:%M:%S", level=loglevel)
+
+now = datetime.now()
+
+backup_name = now.strftime('%Y%m%d-%H%M%S')
+backup_type = None
+
+if now.day == cmdline_args.monthly_day:
+    backup_type = 'monthly'
+elif calendar.weekday(now.year, now.month, now.day) == cmdline_args.weekly_day:
+    backup_type = 'weekly'
+else:
+    backup_type = 'daily'
+
+backup_name += '-{}'.format(backup_type)
+
+log.debug('backup type: %s', backup_type)
+log.debug('backup basename: %s', backup_name)
+
+dirs = set(cmdline_args.dir)
+
+def tarsnap_cmd(*args):
+    cmd = ['tarsnap']
+    cmd += args
+    return cmd
+
+def exec_cmd(cmd, **kwargs):
+    log.debug('executing %s', ' '.join(cmd))
+    subprocess.check_call(cmd, **kwargs)
+
+# create the backups
+for dir in dirs:
+    cmd = tarsnap_cmd('-c', '-f', '{}-{}'.format(backup_name, dir),
+        dir)
+    log.info('backing up %s', dir)
+    if not cmdline_args.dry_run:
+        exec_cmd(cmd)
+
+# retrieve a list of archives and remove old ones
+archives = os.tmpfile()
+
+exec_cmd(tarsnap_cmd('--list-archives'), stdout=archives,
+    stderr=archives)
+
+if cmdline_args.dry_run:
+    for dir in dirs:
+        archives.write('{}-{}\n'.format(backup_name, dir))
+
+delete_archives = []
+
+def get_oldest(lst, keep):
+    return sorted(lst, reverse=True)[keep:]
+
+for dir in dirs:
+    archives.seek(0)
+
+    re_daily = re.compile(r'^\d{8}-\d{6}-daily-' + dir)
+    re_weekly = re.compile(r'^\d{8}-\d{6}-weekly-' + dir)
+    re_monthly = re.compile(r'^\d{8}-\d{6}-monthly-' + dir)
+
+    daily_archives = []
+    weekly_archives = []
+    monthly_archives = []
+
+    for line in archives:
+        line = line.strip()
+        if re_daily.match(line):
+            daily_archives.append(line)
+        elif re_weekly.match(line):
+            weekly_archives.append(line)
+        elif re_monthly.match(line):
+            monthly_archives.append(line)
+
+    delete_archives += get_oldest(daily_archives,
+        cmdline_args.daily)
+    delete_archives += get_oldest(weekly_archives,
+        cmdline_args.weekly)
+    delete_archives += get_oldest(monthly_archives,
+        cmdline_args.monthly)
+
+archives.close()
+
+for archive in delete_archives:
+    log.info('deleting archive %s', archive)
+
+    if not cmdline_args.dry_run:
+        exec_cmd(tarsnap_cmd('-d', '-f', archive))