Files
dvc/dvc/remote/ssh/connection.py
T
2019-11-04 21:02:51 +01:00

313 lines
9.3 KiB
Python

import os
import posixpath
import logging
import errno
import stat
from funcy import cached_property
try:
import paramiko
except ImportError:
paramiko = None
from dvc.utils import tmp_fname
from dvc.utils.compat import ignore_file_not_found
from dvc.progress import Tqdm
from dvc.exceptions import DvcException
from dvc.remote.base import RemoteCmdError
logger = logging.getLogger(__name__)
def sizeof_fmt(num, suffix="B"):
""" Convert number of bytes to human-readable string """
for unit in ["", "K", "M", "G", "T", "P", "E", "Z"]:
if abs(num) < 1024.0:
return "%3.1f%s%s" % (num, unit, suffix)
num /= 1024.0
return "%.1f%s%s" % (num, "Y", suffix)
class SSHConnection:
def __init__(self, host, *args, **kwargs):
logger.debug(
"Establishing ssh connection with '{host}' "
"through port '{port}' as user '{username}'".format(
host=host, **kwargs
)
)
self.timeout = kwargs.get("timeout", 1800)
self._ssh = paramiko.SSHClient()
self._ssh.load_system_host_keys()
self._ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
self._ssh.connect(host, *args, **kwargs)
self._ssh.get_transport().set_keepalive(10)
self._sftp_channels = []
@property
def sftp(self):
if not self._sftp_channels:
self._sftp_channels = [self._ssh.open_sftp()]
return self._sftp_channels[0]
def close(self):
for sftp in self._sftp_channels:
sftp.close()
self._ssh.close()
def st_mode(self, path):
with ignore_file_not_found():
return self.sftp.lstat(path).st_mode
return 0
def getsize(self, path):
with ignore_file_not_found():
return self.sftp.lstat(path).st_size
return 0
def exists(self, path, sftp=None):
return bool(self.st_mode(path))
def isdir(self, path):
return stat.S_ISDIR(self.st_mode(path))
def isfile(self, path):
return stat.S_ISREG(self.st_mode(path))
def islink(self, path):
return stat.S_ISLNK(self.st_mode(path))
def makedirs(self, path):
# Single stat call will say whether this is a dir, a file or a link
st_mode = self.st_mode(path)
if stat.S_ISDIR(st_mode):
return
if stat.S_ISREG(st_mode) or stat.S_ISLNK(st_mode):
raise DvcException(
"a file with the same name '{}' already exists".format(path)
)
head, tail = posixpath.split(path)
if head:
self.makedirs(head)
if tail:
try:
self.sftp.mkdir(path)
except IOError as e:
# Since paramiko errors are very vague we need to recheck
# whether it's because path already exists or something else
if e.errno == errno.EACCES or not self.exists(path):
raise DvcException(
"unable to create remote directory '{}'".format(path),
cause=e,
)
def walk(self, directory, topdown=True):
# NOTE: original os.walk() implementation [1] with default options was
# used as a template.
#
# [1] https://github.com/python/cpython/blob/master/Lib/os.py
try:
dir_entries = self.sftp.listdir_attr(directory)
except IOError as exc:
raise DvcException(
"couldn't get the '{}' remote directory files list".format(
directory
),
cause=exc,
)
dirs = []
nondirs = []
for entry in dir_entries:
name = entry.filename
if stat.S_ISDIR(entry.st_mode):
dirs.append(name)
else:
nondirs.append(name)
if topdown:
yield directory, dirs, nondirs
for dname in dirs:
newpath = posixpath.join(directory, dname)
for entry in self.walk(newpath, topdown=topdown):
yield entry
if not topdown:
yield directory, dirs, nondirs
def walk_files(self, directory):
for root, dirs, files in self.walk(directory):
for fname in files:
yield posixpath.join(root, fname)
def _remove_file(self, path):
with ignore_file_not_found():
self.sftp.remove(path)
def _remove_dir(self, path):
for root, dirs, files in self.walk(path, topdown=False):
for fname in files:
path = posixpath.join(root, fname)
with ignore_file_not_found():
self._remove_file(path)
for dname in dirs:
path = posixpath.join(root, dname)
with ignore_file_not_found():
self.sftp.rmdir(dname)
with ignore_file_not_found():
self.sftp.rmdir(path)
def remove(self, path):
if self.isdir(path):
self._remove_dir(path)
else:
self._remove_file(path)
def download(self, src, dest, no_progress_bar=False, progress_title=None):
with Tqdm(
desc=progress_title or os.path.basename(src),
disable=no_progress_bar,
bytes=True,
) as pbar:
self.sftp.get(src, dest, callback=pbar.update_to)
def move(self, src, dst):
self.makedirs(posixpath.dirname(dst))
self.sftp.rename(src, dst)
def upload(self, src, dest, no_progress_bar=False, progress_title=None):
self.makedirs(posixpath.dirname(dest))
tmp_file = tmp_fname(dest)
if not progress_title:
progress_title = posixpath.basename(dest)
with Tqdm(
desc=progress_title, disable=no_progress_bar, bytes=True
) as pbar:
self.sftp.put(src, tmp_file, callback=pbar.update_to)
self.sftp.rename(tmp_file, dest)
def execute(self, cmd):
stdin, stdout, stderr = self._ssh.exec_command(cmd)
channel = stdout.channel
stdin.close()
channel.shutdown_write()
stdout_chunks = []
stderr_chunks = []
while (
not channel.closed
or channel.recv_ready()
or channel.recv_stderr_ready()
):
import select
got_chunk = False
readq, _, _ = select.select([stdout.channel], [], [], self.timeout)
for c in readq:
if c.recv_ready():
stdout_chunks.append(stdout.channel.recv(len(c.in_buffer)))
got_chunk = True
if c.recv_stderr_ready():
stderr_len = len(c.in_stderr_buffer)
s = stderr.channel.recv_stderr(stderr_len)
stderr_chunks.append(s)
got_chunk = True
if (
not got_chunk
and stdout.channel.exit_status_ready()
and not stderr.channel.recv_stderr_ready()
and not stdout.channel.recv_ready()
):
stdout.channel.shutdown_read()
stdout.channel.close()
break
stdout.close()
stderr.close()
ret = stdout.channel.recv_exit_status()
if ret != 0:
err = b"".join(stderr_chunks).decode("utf-8")
raise RemoteCmdError("ssh", cmd, ret, err)
return b"".join(stdout_chunks).decode("utf-8")
@cached_property
def uname(self):
return self.execute("uname").strip()
def md5(self, path):
"""
Use different md5 commands depending on the OS:
- Darwin's `md5` returns BSD-style checksums by default
- Linux's `md5sum` needs the `--tag` flag for a similar output
Example:
MD5 (foo.txt) = f3d220a856b52aabbf294351e8a24300
"""
if self.uname == "Linux":
md5 = self.execute("md5sum " + path).split()[0]
elif self.uname == "Darwin":
md5 = self.execute("md5 " + path).split()[-1]
else:
raise DvcException(
"'{}' is not supported as a SSH remote".format(self.uname)
)
assert len(md5) == 32
return md5
def copy(self, src, dest):
self.execute("cp {} {}".format(src, dest))
def open_max_sftp_channels(self):
# If there are more than 1 it means we've already opened max amount
if len(self._sftp_channels) <= 1:
while True:
try:
self._sftp_channels.append(self._ssh.open_sftp())
except paramiko.ssh_exception.ChannelException:
if not self._sftp_channels:
raise
break
return self._sftp_channels
def open(self, *args, **kwargs):
return self.sftp.open(*args, **kwargs)
def symlink(self, src, dest):
self.sftp.symlink(src, dest)
def reflink(self, src, dest):
if self.uname == "Linux":
return self.execute("cp --reflink {} {}".format(src, dest))
if self.uname == "Darwin":
return self.execute("cp -c {} {}".format(src, dest))
raise DvcException(
"'{}' is not supported as a SSH remote".format(self.uname)
)
def hardlink(self, src, dest):
self.execute("ln {} {}".format(src, dest))