diff --git a/lvmsnapshot.py b/lvmsnapshot.py
index 9927dbfee24b2d4f5ef6a194bd29ef864b80a311..345fb8e4b9993d149c6419ebee1260ee4e884147 100644
--- a/lvmsnapshot.py
+++ b/lvmsnapshot.py
@@ -21,17 +21,24 @@
# sort by period
# mark snapshots to keep, from oldest within period to new
# delete unmarked snapshots
-# periods are cumulative
import os
import re
-from datetime import datetime
+from datetime import datetime, timedelta
import subprocess as sp
import json
from contextlib import contextmanager
+from collections import OrderedDict
SNAPSHOT_BASE_DIR = "/snapshots"
TIMESTAMP_FORMAT = "%Y-%m-%d-%H-%M"
+PERIOD_KEYS = OrderedDict([
+ ("y", 365 * 86400),
+ ("m", 31 * 86400),
+ ("d", 86400),
+ ("H", 3600),
+ ("M", 60),
+])
@contextmanager
def xfs_freeze(mountpoint):
@@ -52,6 +59,15 @@ class Volume:
self.volume_group = volume_group
self.name = name
+ def __repr__(self):
+ return self.get_full_name()
+
+ def __eq__(self, other):
+ return hash(self) == hash(other)
+
+ def __hash__(self):
+ return sum(ord(c) * i for i, c in enumerate(self.get_full_name()))
+
def get_full_name(self):
return "{}/{}".format(self.volume_group, self.name)
@@ -65,7 +81,7 @@ class Volume:
"--source", mapper_device,
"--json"
]
- result = sp.check_output(command)
+ result = sp.check_output(command).decode("utf-8")
data = json.loads(result)
filesystems = data["filesystems"]
if len(filesystems) < 1:
@@ -79,6 +95,9 @@ class Snapshot:
self.timestamp = timestamp
self.active = active
+ def __repr__(self):
+ return self.get_name()
+
def get_timestamp_str(self):
return self.timestamp.strftime(TIMESTAMP_FORMAT)
@@ -164,7 +183,7 @@ class Snapshot:
"-o", "vg_name,lv_name,lv_active,origin,lv_role",
"--reportformat", "json"
]
- result = sp.check_output(list_command)
+ result = sp.check_output(list_command).decode("utf-8")
data = json.loads(result)
raw_volumes = data["report"][0]["lv"]
parent_name_map = {}
@@ -182,17 +201,58 @@ class Snapshot:
volume = Volume(volume_group, volume_name)
snapshots[volume] = []
parent_name_map[volume.name] = volume
- else:
- print("Ignoring volume {}/{}".format(volume_group, volume_name)) # todo: remove this output
for (volume_group, volume_name, active, origin, roles) in raw_snapshots:
- parent_name, timestamp = Snapshot.parse_name(volume_name)
- if parent_name != origin:
- raise Exception("Parent volume name not matching: '{}' != '{}'".format(parent_name, origin))
- parent = parent_name_map[parent_name]
- snapshot = Snapshot(parent, timestamp, active)
- snapshots[parent].append(snapshot)
+ try:
+ parent_name, timestamp = Snapshot.parse_name(volume_name)
+ if parent_name != origin:
+ raise Exception("Parent volume name not matching: "
+ "'{}' != '{}'".format(parent_name, origin))
+ parent = parent_name_map[parent_name]
+ snapshot = Snapshot(parent, timestamp, active)
+ snapshots[parent].append(snapshot)
+ except ValueError:
+ # a snapshot, but not named like the autosnapshots
+ # we better keep the hands off them
+ pass
return snapshots
+
+class Period:
+ def __init__(self, target_number, interval):
+ self.target_number = target_number
+ self.interval = interval
+
+ def __repr__(self):
+ return "Keep {} at interval {}d{}s (since {})".format(
+ self.target_number, self.interval.days,
+ self.interval.seconds, self.get_start())
+
+ def get_start(self):
+ return datetime.now() - self.target_number * self.interval
+
+ @staticmethod
+ def build_regex(period_keys=None):
+ if period_keys is None:
+ period_keys = PERIOD_KEYS
+ parts = [r"(?:(?P<{0}>\d+){0})?".format(key) for key in period_keys]
+ return "".join(parts)
+
+ @staticmethod
+ def parse_interval(text, period_keys=None):
+ if period_keys is None:
+ period_keys = PERIOD_KEYS
+ regex = Period.build_regex(period_keys)
+ match = re.fullmatch(regex, text)
+ if match is None:
+ raise Exception("Invalid interval config: '{}', "
+ "needs to match '{}'".format(text, regex))
+ seconds = 0
+ groups = match.groupdict()
+ for key in period_keys:
+ if groups[key] is not None:
+ seconds += period_keys[key] * int(groups[key])
+ return timedelta(seconds=seconds)
+
def load_config():
import sys
import toml
@@ -205,10 +265,45 @@ def load_config():
with open(config_path, "r") as config_file:
return toml.load(config_file)
+def parse_config(config):
+ periods = {}
+ for volume_conf in config["volume"]:
+ name = volume_conf["name"]
+ volume_group = volume_conf["volume_group"]
+ volume = Volume(volume_group, name)
+ periods[volume] = []
+ for raw_period in volume_conf["keep"]:
+ interval = Period.parse_interval(raw_period["interval"])
+ number = int(raw_period["number"])
+ periods[volume].append(
+ Period(target_number=number, interval=interval))
+ return periods
+
+def mark_snapshots(snapshots, periods):
+ all_snapshots = set(snapshots)
+ marked_snapshots = set()
+ budgets = {period: period.target_number for period in periods}
+ for snapshot in sorted(snapshots, key=lambda s: s.timestamp):
+ for period in sorted(periods, key=Period.interval):
+ if (budgets[period] > 0
+ and period.get_start() < snapshot.timestamp):
+ marked_snapshots.add(snapshot)
+ budgets[period] -= 1
+ unmarked_snapshots = all_snapshots - marked_snapshots
+ return unmarked_snapshots
+
def main():
config = load_config()
- print(config)
snapshots = Snapshot.list_snapshots()
+ periods = parse_config(config)
+ for volume in set(periods.keys()) - set(snapshots.keys()):
+ print("Warning: Volume {} is configured but does not exist or has no snapshots.".format(volume))
+ for volume in set(snapshots.keys()) - set(periods.keys()):
+ print("Warning: Volume {} does exist but is not configured.".format(volume))
+ snapshots.pop(volume)
+ for volume in snapshots:
+ unmarked_snapshots = mark_snapshots(snapshots[volume], periods[volume])
+ print(unmarked_snapshots)
if __name__ == "__main__":
main()