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Mini Shell
Mini Shell
# coding=utf-8
#
# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
import json
import logging
import os
import pwd
import shutil
import sys
import zlib
from contextlib import contextmanager
from typing import List, Optional # NOQA
SNAPSHOT_PATH = '/var/lve/snapshots'
SNAPSHOT_EXT = '.snapshot'
SNAPSHOT_EXT_LEN = len(SNAPSHOT_EXT)
class Snapshot(object):
"""
This class is responsible for loading and saving snapshot files for the interval
The files will be saved in a format of: /var/lve/snapshots/[uid]/dump_time.snapshot
dump_time is the timestamp/integer
The directories /var/lve/snaphosts/[uid] and the dump files itself will be owned by user
They will not be readable by other users.
"""
def __init__(self, incident, compresslevel=1):
# type: (dict, int) -> None
self.compresslevel = compresslevel
self.incident = incident
self.log = logging.getLogger('lib-snapshot')
def save(self, data):
# type: (dict) -> str
dump_date = data['dump_time']
assert dump_date is not None
# convert possible non-ascii data to unicode
self._replace_unicode_data(data)
json_compressed = zlib.compress(json.dumps(data).encode(), self.compresslevel)
with self.create_file(dump_date) as f:
f.write(json_compressed)
self.log.debug('Snapshot dumped to file %s', f.name)
return f.name
@staticmethod
def _to_unicode(obj):
if isinstance(obj, bytes):
return obj.decode('utf-8', 'replace')
return obj
def _replace_unicode_data(self, data):
# type: (dict) -> None
u_queries = []
for query in data.get('snap_sql', []):
u_queries.append(list(map(self._to_unicode, query)))
data['snap_sql'] = u_queries
u_urls = []
for http in data.get('snap_http', []):
u_urls.append(list(map(self._to_unicode, http)))
data['snap_http'] = u_urls
def get_file_list(self):
# type: () -> List[str]
dir_ = self.get_dir()
if os.path.isdir(dir_):
return os.listdir(dir_)
return []
def get_ts_list(self, from_ts, to_ts):
# type: (Optional[int], Optional[int]) -> List[int]
"""
Return ordered list of timestamps when snapshots for this use were created
:param from_ts:
:param to_ts:
:return: list of timesteamps, ordered for that period
"""
return self.snapshot_filter(self.get_file_list(), from_ts, to_ts)
def get_snapshots(self, from_ts, to_ts):
# type: (Optional[int], Optional[int]) -> list
"""
Get all snapshot for a period
:param from_ts
:param to_ts
:return: list of snapshots, ordered by date
"""
result = []
for ts in self.get_ts_list(from_ts, to_ts):
try:
filename = self.get_file_name(self.ts_to_name(ts))
if not os.geteuid():
with drop_privileges(self.incident["uid"]):
content = self.read_file_content(filename)
else:
content = self.read_file_content(filename)
result.append(json.loads(content))
except (IOError, ValueError, OSError) as ve:
self.log.warning(
"Corrupted file: %s (%s)",
self.get_file_name(self.ts_to_name(ts)),
str(ve),
)
return result
def read_file_content(self, filename):
# type: (str) -> str
with open(filename, 'rb') as f:
content = f.read()
try:
content = zlib.decompress(content)
except zlib.error:
compressed_content = zlib.compress(content, self.compresslevel)
with open(filename, 'wb') as f:
f.write(compressed_content)
return content.decode()
def get_incident_snapshots(self):
# type: () -> list
"""
Load all snapshots for given incident
:return: list of snapshots
"""
return self.get_snapshots(self.incident["incident_start_time"], self.incident["incident_end_time"])
def get_dir(self):
# type: () -> str
return os.path.join(SNAPSHOT_PATH, str(self.incident["uid"]))
def get_file_name(self, name):
# type: (str) -> str
return os.path.join(self.get_dir(), name)
def create_file(self, dump_date):
# type: (int) -> open()
"""
create file, change its ownership & permissions if needed. Create directories if needed as well
:param dump_date: int timestamp used as file name
:return: open File object
"""
dir_ = self.get_dir()
if not os.path.exists(dir_):
try: # sacrifice security if we cannot setup ownership properly
os.makedirs(dir_)
os.chmod(dir_, 0o751)
os.chown(dir_, self.incident["uid"], 0)
except (IOError, OSError) as e:
self.log.error('Unable to create dir %s (%s)', dir_, str(e))
file_name = self.get_file_name(self.ts_to_name(dump_date))
with drop_privileges(self.incident["uid"]):
file_ = open(file_name, 'wb') # pylint: disable=consider-using-with
try:
os.fchmod(file_.fileno(), 0o400)
except (IOError, OSError) as e:
self.log.error('Unable to set file permissions %s (%s)', file_name, str(e))
return file_
def delete_old(self, to_ts):
# type: (int) -> None
"""
Delete old snapshots. If there are no more
:param to_ts: up to which timestamp to remove snapshots
:return: None
"""
_dir = self.get_dir()
files = os.listdir(_dir)
all_snapshots = self.snapshot_filter(files)
ts_to_remove = self.snapshot_filter(files, to_ts=to_ts)
if all_snapshots == ts_to_remove:
shutil.rmtree(_dir, ignore_errors=True)
else:
for ts in ts_to_remove:
os.remove(self.get_file_name(self.ts_to_name(ts)))
@staticmethod
def get_ts(file_):
# type: (str) -> Optional[int]
if file_.endswith(SNAPSHOT_EXT):
ts = file_[0:-SNAPSHOT_EXT_LEN]
if ts.isdigit():
try:
return int(ts)
except ValueError:
pass
return None
@staticmethod
def snapshot_filter(files, from_ts=None, to_ts=None):
# type: (List[str], Optional[int], Optional[int]) -> List[int]
if from_ts is None:
from_ts = 0
if to_ts is None:
to_ts = sys.maxsize
result = []
for filename in files:
ts = Snapshot.get_ts(filename)
if ts is not None and from_ts <= ts <= to_ts:
result.append(ts)
return sorted(result)
@staticmethod
def ts_to_name(ts):
# type: (int) -> str
return str(ts) + SNAPSHOT_EXT
@contextmanager
def drop_privileges(uid):
old_uid, old_gid, old_groups = os.getuid(), os.getgid(), os.getgroups()
gid = pwd.getpwnam('nobody')[3]
os.setgroups([])
os.setegid(gid)
os.seteuid(uid)
try:
yield
finally:
os.seteuid(old_uid)
os.setegid(old_gid)
os.setgroups(old_groups)
Zerion Mini Shell 1.0