borgbackup/borg/remote.py
Thomas Waldmann e68b800d01 remove unused "repair" rpc method
there is no such method in the code.
we use "check" method to repair the repo, so maybe this was left over
from a time when repair was separate from check.
2016-01-16 18:58:52 +01:00

398 lines
15 KiB
Python

import errno
import fcntl
import logging
import os
import select
import shlex
from subprocess import Popen, PIPE
import sys
import tempfile
import traceback
from . import __version__
from .helpers import Error, IntegrityError, sysinfo
from .repository import Repository
import msgpack
RPC_PROTOCOL_VERSION = 2
BUFSIZE = 10 * 1024 * 1024
class ConnectionClosed(Error):
"""Connection closed by remote host"""
class ConnectionClosedWithHint(ConnectionClosed):
"""Connection closed by remote host. {}"""
class PathNotAllowed(Error):
"""Repository path not allowed"""
class InvalidRPCMethod(Error):
"""RPC method {} is not valid"""
class RepositoryServer: # pragma: no cover
rpc_methods = (
'__len__',
'check',
'commit',
'delete',
'destroy',
'get',
'list',
'negotiate',
'open',
'put',
'rollback',
'save_key',
'load_key',
'break_lock',
)
def __init__(self, restrict_to_paths):
self.repository = None
self.restrict_to_paths = restrict_to_paths
def serve(self):
stdin_fd = sys.stdin.fileno()
stdout_fd = sys.stdout.fileno()
stderr_fd = sys.stdout.fileno()
# Make stdin non-blocking
fl = fcntl.fcntl(stdin_fd, fcntl.F_GETFL)
fcntl.fcntl(stdin_fd, fcntl.F_SETFL, fl | os.O_NONBLOCK)
# Make stdout blocking
fl = fcntl.fcntl(stdout_fd, fcntl.F_GETFL)
fcntl.fcntl(stdout_fd, fcntl.F_SETFL, fl & ~os.O_NONBLOCK)
# Make stderr blocking
fl = fcntl.fcntl(stderr_fd, fcntl.F_GETFL)
fcntl.fcntl(stderr_fd, fcntl.F_SETFL, fl & ~os.O_NONBLOCK)
unpacker = msgpack.Unpacker(use_list=False)
while True:
r, w, es = select.select([stdin_fd], [], [], 10)
if r:
data = os.read(stdin_fd, BUFSIZE)
if not data:
return
unpacker.feed(data)
for unpacked in unpacker:
if not (isinstance(unpacked, tuple) and len(unpacked) == 4):
raise Exception("Unexpected RPC data format.")
type, msgid, method, args = unpacked
method = method.decode('ascii')
try:
if method not in self.rpc_methods:
raise InvalidRPCMethod(method)
try:
f = getattr(self, method)
except AttributeError:
f = getattr(self.repository, method)
res = f(*args)
except BaseException as e:
logging.exception('Borg %s: exception in RPC call:', __version__)
logging.error(sysinfo())
exc = "Remote Exception (see remote log for the traceback)"
os.write(stdout_fd, msgpack.packb((1, msgid, e.__class__.__name__, exc)))
else:
os.write(stdout_fd, msgpack.packb((1, msgid, None, res)))
if es:
return
def negotiate(self, versions):
return RPC_PROTOCOL_VERSION
def open(self, path, create=False, lock_wait=None, lock=True):
path = os.fsdecode(path)
if path.startswith('/~'):
path = path[1:]
path = os.path.realpath(os.path.expanduser(path))
if self.restrict_to_paths:
for restrict_to_path in self.restrict_to_paths:
if path.startswith(os.path.realpath(restrict_to_path)):
break
else:
raise PathNotAllowed(path)
self.repository = Repository(path, create, lock_wait=lock_wait, lock=lock)
return self.repository.id
class RemoteRepository:
extra_test_args = []
class RPCError(Exception):
def __init__(self, name):
self.name = name
def __init__(self, location, create=False, lock_wait=None, lock=True, args=None):
self.location = location
self.preload_ids = []
self.msgid = 0
self.to_send = b''
self.cache = {}
self.ignore_responses = set()
self.responses = {}
self.unpacker = msgpack.Unpacker(use_list=False)
self.p = None
testing = location.host == '__testsuite__'
borg_cmd = self.borg_cmd(args, testing)
env = dict(os.environ)
if not testing:
borg_cmd = self.ssh_cmd(location) + borg_cmd
# pyinstaller binary adds LD_LIBRARY_PATH=/tmp/_ME... but we do not want
# that the system's ssh binary picks up (non-matching) libraries from there
env.pop('LD_LIBRARY_PATH', None)
self.p = Popen(borg_cmd, bufsize=0, stdin=PIPE, stdout=PIPE, stderr=PIPE, env=env)
self.stdin_fd = self.p.stdin.fileno()
self.stdout_fd = self.p.stdout.fileno()
self.stderr_fd = self.p.stderr.fileno()
fcntl.fcntl(self.stdin_fd, fcntl.F_SETFL, fcntl.fcntl(self.stdin_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
fcntl.fcntl(self.stdout_fd, fcntl.F_SETFL, fcntl.fcntl(self.stdout_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
fcntl.fcntl(self.stderr_fd, fcntl.F_SETFL, fcntl.fcntl(self.stderr_fd, fcntl.F_GETFL) | os.O_NONBLOCK)
self.r_fds = [self.stdout_fd, self.stderr_fd]
self.x_fds = [self.stdin_fd, self.stdout_fd, self.stderr_fd]
try:
version = self.call('negotiate', RPC_PROTOCOL_VERSION)
except ConnectionClosed:
raise ConnectionClosedWithHint('Is borg working on the server?')
if version != RPC_PROTOCOL_VERSION:
raise Exception('Server insisted on using unsupported protocol version %d' % version)
self.id = self.call('open', location.path, create, lock_wait, lock)
def __del__(self):
self.close()
def __repr__(self):
return '<%s %s>' % (self.__class__.__name__, self.location.canonical_path())
def borg_cmd(self, args, testing):
"""return a borg serve command line"""
# give some args/options to "borg serve" process as they were given to us
opts = []
if args is not None:
opts.append('--umask=%03o' % args.umask)
root_logger = logging.getLogger()
if root_logger.isEnabledFor(logging.DEBUG):
opts.append('--debug')
elif root_logger.isEnabledFor(logging.INFO):
opts.append('--info')
elif root_logger.isEnabledFor(logging.WARNING):
pass # warning is default
else:
raise ValueError('log level missing, fix this code')
if testing:
return [sys.executable, '-m', 'borg.archiver', 'serve' ] + opts + self.extra_test_args
else: # pragma: no cover
return [args.remote_path, 'serve'] + opts
def ssh_cmd(self, location):
"""return a ssh command line that can be prefixed to a borg command line"""
args = shlex.split(os.environ.get('BORG_RSH', 'ssh'))
if location.port:
args += ['-p', str(location.port)]
if location.user:
args.append('%s@%s' % (location.user, location.host))
else:
args.append('%s' % location.host)
return args
def call(self, cmd, *args, **kw):
for resp in self.call_many(cmd, [args], **kw):
return resp
def call_many(self, cmd, calls, wait=True, is_preloaded=False):
if not calls:
return
def fetch_from_cache(args):
msgid = self.cache[args].pop(0)
if not self.cache[args]:
del self.cache[args]
return msgid
calls = list(calls)
waiting_for = []
w_fds = [self.stdin_fd]
while wait or calls:
while waiting_for:
try:
error, res = self.responses.pop(waiting_for[0])
waiting_for.pop(0)
if error:
if error == b'DoesNotExist':
raise Repository.DoesNotExist(self.location.orig)
elif error == b'AlreadyExists':
raise Repository.AlreadyExists(self.location.orig)
elif error == b'CheckNeeded':
raise Repository.CheckNeeded(self.location.orig)
elif error == b'IntegrityError':
raise IntegrityError(res)
elif error == b'PathNotAllowed':
raise PathNotAllowed(*res)
elif error == b'ObjectNotFound':
raise Repository.ObjectNotFound(res[0], self.location.orig)
elif error == b'InvalidRPCMethod':
raise InvalidRPCMethod(*res)
else:
raise self.RPCError(res.decode('utf-8'))
else:
yield res
if not waiting_for and not calls:
return
except KeyError:
break
r, w, x = select.select(self.r_fds, w_fds, self.x_fds, 1)
if x:
raise Exception('FD exception occurred')
for fd in r:
if fd is self.stdout_fd:
data = os.read(fd, BUFSIZE)
if not data:
raise ConnectionClosed()
self.unpacker.feed(data)
for unpacked in self.unpacker:
if not (isinstance(unpacked, tuple) and len(unpacked) == 4):
raise Exception("Unexpected RPC data format.")
type, msgid, error, res = unpacked
if msgid in self.ignore_responses:
self.ignore_responses.remove(msgid)
else:
self.responses[msgid] = error, res
elif fd is self.stderr_fd:
data = os.read(fd, 32768)
if not data:
raise ConnectionClosed()
data = data.decode('utf-8')
for line in data.splitlines(True): # keepends=True for py3.3+
if line.startswith('$LOG '):
_, level, msg = line.split(' ', 2)
level = getattr(logging, level, logging.CRITICAL) # str -> int
logging.log(level, msg.rstrip())
else:
sys.stderr.write("Remote: " + line)
if w:
while not self.to_send and (calls or self.preload_ids) and len(waiting_for) < 100:
if calls:
if is_preloaded:
if calls[0] in self.cache:
waiting_for.append(fetch_from_cache(calls.pop(0)))
else:
args = calls.pop(0)
if cmd == 'get' and args in self.cache:
waiting_for.append(fetch_from_cache(args))
else:
self.msgid += 1
waiting_for.append(self.msgid)
self.to_send = msgpack.packb((1, self.msgid, cmd, args))
if not self.to_send and self.preload_ids:
args = (self.preload_ids.pop(0),)
self.msgid += 1
self.cache.setdefault(args, []).append(self.msgid)
self.to_send = msgpack.packb((1, self.msgid, cmd, args))
if self.to_send:
try:
self.to_send = self.to_send[os.write(self.stdin_fd, self.to_send):]
except OSError as e:
# io.write might raise EAGAIN even though select indicates
# that the fd should be writable
if e.errno != errno.EAGAIN:
raise
if not self.to_send and not (calls or self.preload_ids):
w_fds = []
self.ignore_responses |= set(waiting_for)
def check(self, repair=False, save_space=False):
return self.call('check', repair, save_space)
def commit(self, save_space=False):
return self.call('commit', save_space)
def rollback(self, *args):
return self.call('rollback')
def destroy(self):
return self.call('destroy')
def __len__(self):
return self.call('__len__')
def list(self, limit=None, marker=None):
return self.call('list', limit, marker)
def get(self, id_):
for resp in self.get_many([id_]):
return resp
def get_many(self, ids, is_preloaded=False):
for resp in self.call_many('get', [(id_,) for id_ in ids], is_preloaded=is_preloaded):
yield resp
def put(self, id_, data, wait=True):
return self.call('put', id_, data, wait=wait)
def delete(self, id_, wait=True):
return self.call('delete', id_, wait=wait)
def save_key(self, keydata):
return self.call('save_key', keydata)
def load_key(self):
return self.call('load_key')
def break_lock(self):
return self.call('break_lock')
def close(self):
if self.p:
self.p.stdin.close()
self.p.stdout.close()
self.p.wait()
self.p = None
def preload(self, ids):
self.preload_ids += ids
class RepositoryCache:
"""A caching Repository wrapper
Caches Repository GET operations using a local temporary Repository.
"""
def __init__(self, repository):
self.repository = repository
tmppath = tempfile.mkdtemp(prefix='borg-tmp')
self.caching_repo = Repository(tmppath, create=True, exclusive=True)
def __del__(self):
self.caching_repo.destroy()
def get(self, key):
return next(self.get_many([key]))
def get_many(self, keys):
unknown_keys = [key for key in keys if key not in self.caching_repo]
repository_iterator = zip(unknown_keys, self.repository.get_many(unknown_keys))
for key in keys:
try:
yield self.caching_repo.get(key)
except Repository.ObjectNotFound:
for key_, data in repository_iterator:
if key_ == key:
self.caching_repo.put(key, data)
yield data
break
# Consume any pending requests
for _ in repository_iterator:
pass
def cache_if_remote(repository):
if isinstance(repository, RemoteRepository):
return RepositoryCache(repository)
return repository