#
# Copyright 2014 Red Hat, Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#
# Refer to the README and COPYING files for full details of the license
#
import Queue
import array
import collections
import fcntl
import functools
import json
import logging
import os
import select
import socket
import subprocess
import sys
import termios
import threading
import time
import tty
import yaml
import constants
from .log_utils import (LogTask, setup_prefix_logging)
LOGGER = logging.getLogger(__name__)
[docs]def _ret_via_queue(func, queue):
try:
queue.put({'return': func()})
except Exception:
LOGGER.exception('Error while running thread')
queue.put({'exception': sys.exc_info()})
[docs]def func_vector(target, args_sequence):
return [functools.partial(target, *args) for args in args_sequence]
[docs]class VectorThread:
def __init__(self, targets):
self.targets = targets
self.results = None
[docs] def start_all(self):
self.thread_handles = []
for target in self.targets:
q = Queue.Queue()
t = threading.Thread(target=_ret_via_queue, args=(target, q))
self.thread_handles.append((t, q))
t.start()
[docs] def join_all(self, raise_exceptions=True):
if self.results:
return self.results
for t, q in self.thread_handles:
t.join()
self.results = map(lambda (t, q): q.get(), self.thread_handles)
if raise_exceptions:
for result in self.results:
if 'exception' in result:
exc_info = result['exception']
raise exc_info[1], None, exc_info[2]
return map(lambda x: x.get('return', None), self.results)
[docs]def invoke_in_parallel(func, *args_sequences):
vt = VectorThread(func_vector(func, zip(*args_sequences)))
vt.start_all()
vt.join_all()
_CommandStatus = collections.namedtuple(
'CommandStatus', ('code', 'out', 'err')
)
[docs]class CommandStatus(_CommandStatus):
def __nonzero__(self):
return self.code
[docs]def _run_command(
command,
input_data=None,
stdin=None,
out_pipe=subprocess.PIPE,
err_pipe=subprocess.PIPE,
env=None,
**kwargs
):
"""
Runs a command
Args:
command(list of str): args of the command to execute, including the
command itself as command[0] as `['ls', '-l']`
input_data(str): If passed, will feed that data to the subprocess
through stdin
out_pipe(int or file): File descriptor as passed to
:ref:subprocess.Popen to use as stdout
stdin(int or file): File descriptor as passed to
:ref:subprocess.Popen to use as stdin
err_pipe(int or file): File descriptor as passed to
:ref:subprocess.Popen to use as stderr
env(dict of str:str): If set, will use the given dict as env for the
subprocess
**kwargs: Any other keyword args passed will be passed to the
:ref:subprocess.Popen call
Returns:
lago.utils.CommandStatus: result of the interactive execution
"""
# add libexec to PATH if needed
if constants.LIBEXEC_DIR not in os.environ['PATH'].split(':'):
os.environ['PATH'] = '%s:%s' % (
constants.LIBEXEC_DIR, os.environ['PATH']
)
if input_data and not stdin:
kwargs['stdin'] = subprocess.PIPE
elif stdin:
kwargs['stdin'] = stdin
if env is None:
env = os.environ.copy()
else:
env['PATH'] = ':'.join(
list(
set(
env.get('PATH', '').split(':') + os.environ[
'PATH'
].split(':')
),
),
)
popen = subprocess.Popen(
command,
stdout=out_pipe,
stderr=err_pipe,
env=env,
**kwargs
)
out, err = popen.communicate(input_data)
LOGGER.debug('command exit with %d', popen.returncode)
if out:
LOGGER.debug('command stdout: %s', out)
if err:
LOGGER.debug('command stderr: %s', err)
return CommandStatus(popen.returncode, out, err)
[docs]def run_command(
command,
input_data=None,
out_pipe=subprocess.PIPE,
err_pipe=subprocess.PIPE,
env=None,
**kwargs
):
"""
Runs a command non-interactively
Args:
command(list of str): args of the command to execute, including the
command itself as command[0] as `['ls', '-l']`
input_data(str): If passed, will feed that data to the subprocess
through stdin
out_pipe(int or file): File descriptor as passed to
:ref:subprocess.Popen to use as stdout
err_pipe(int or file): File descriptor as passed to
:ref:subprocess.Popen to use as stderr
env(dict of str:str): If set, will use the given dict as env for the
subprocess
**kwargs: Any other keyword args passed will be passed to the
:ref:subprocess.Popen call
Returns:
lago.utils.CommandStatus: result of the interactive execution
"""
with LogTask(
'Run command: %s' % str(command[0]),
logger=LOGGER,
level='debug',
):
command_result = _run_command(
command=command,
input_data=input_data,
out_pipe=out_pipe,
err_pipe=err_pipe,
env=env,
**kwargs
)
LOGGER.debug('command exit with %d', command_result.code)
if command_result.out:
LOGGER.debug('command stdout: %s', command_result.out)
if command_result.err:
LOGGER.debug('command stderr: %s', command_result.err)
return command_result
[docs]def run_interactive_command(command, env=None, **kwargs):
"""
Runs a command interactively, reusing the current stdin, stdout and stderr
Args:
command(list of str): args of the command to execute, including the
command itself as command[0] as `['ls', '-l']`
env(dict of str:str): If set, will use the given dict as env for the
subprocess
**kwargs: Any other keyword args passed will be passed to the
:ref:subprocess.Popen call
Returns:
lago.utils.CommandStatus: result of the interactive execution
"""
command_result = _run_command(
command=command,
out_pipe=sys.stdout,
err_pipe=sys.stderr,
stdin=sys.stdin,
env=env,
**kwargs
)
return command_result
[docs]def service_is_enabled(name):
ret, out, _ = run_command(['systemctl', 'is-enabled', name])
if ret == 0 and out.strip() == 'enabled':
return True
return False
# Copied from VDSM: lib/vdsm/utils.py
[docs]class RollbackContext(object):
'''
A context manager for recording and playing rollback.
The first exception will be remembered and re-raised after rollback
Sample usage:
> with RollbackContext() as rollback:
> step1()
> rollback.prependDefer(lambda: undo step1)
> def undoStep2(arg): pass
> step2()
> rollback.prependDefer(undoStep2, arg)
More examples see tests/utilsTests.py @ vdsm code
'''
def __init__(self, *args):
self._finally = []
def __enter__(self):
return self
[docs] def __exit__(self, exc_type, exc_value, traceback):
"""
If this function doesn't return True (or raises a different
exception), python re-raises the original exception once this
function is finished.
"""
undoExcInfo = None
for undo, args, kwargs in self._finally:
try:
undo(*args, **kwargs)
except Exception:
# keep the earliest exception info
if undoExcInfo is None:
undoExcInfo = sys.exc_info()
if exc_type is None and undoExcInfo is not None:
raise undoExcInfo[0], undoExcInfo[1], undoExcInfo[2]
[docs] def defer(self, func, *args, **kwargs):
self._finally.append((func, args, kwargs))
[docs] def prependDefer(self, func, *args, **kwargs):
self._finally.insert(0, (func, args, kwargs))
[docs] def clear(self):
self._finally = []
[docs]class EggTimer:
def __init__(self, timeout):
self.timeout = timeout
def __enter__(self):
self.start_time = time.time()
return self
def __exit__(self, *_):
pass
[docs] def elapsed(self):
return (time.time() - self.start_time) > self.timeout
[docs]def _read_nonblocking(f):
oldfl = fcntl.fcntl(f.fileno(), fcntl.F_GETFL)
try:
fcntl.fcntl(f.fileno(), fcntl.F_SETFL, oldfl | os.O_NONBLOCK)
return f.read()
finally:
fcntl.fcntl(f.fileno(), fcntl.F_SETFL, oldfl)
[docs]def drain_ssh_channel(chan, stdin=None, stdout=sys.stdout, stderr=sys.stderr):
chan.settimeout(0)
out_queue = []
out_all = []
err_queue = []
err_all = []
try:
stdout_is_tty = stdout.isatty()
tty_w = tty_h = -1
except AttributeError:
stdout_is_tty = False
done = False
while not done:
if stdout_is_tty:
arr = array.array('h', range(4))
if not fcntl.ioctl(stdout.fileno(), termios.TIOCGWINSZ, arr):
if tty_h != arr[0] or tty_w != arr[1]:
tty_h, tty_w = arr[:2]
chan.resize_pty(width=tty_w, height=tty_h)
read_streams = []
if not chan.closed:
read_streams.append(chan)
if stdin and not stdin.closed:
read_streams.append(stdin)
write_streams = []
if stdout and out_queue:
write_streams.append(stdout)
if stderr and err_queue:
write_streams.append(stderr)
read, write, _ = select.select(read_streams, write_streams, [], 0.1, )
if stdin in read:
c = _read_nonblocking(stdin)
if c:
chan.send(c)
else:
chan.shutdown_write()
try:
if chan.recv_ready():
c = chan.recv(1024)
if stdout:
out_queue.append(c)
out_all.append(c)
if chan.recv_stderr_ready():
c = chan.recv_stderr(1024)
if stderr:
err_queue.append(c)
err_all.append(c)
except socket.error:
pass
if stdout in write:
stdout.write(out_queue.pop(0))
stdout.flush()
if stderr in write:
stderr.write(err_queue.pop(0))
stderr.flush()
if chan.closed and not out_queue and not err_queue:
done = True
return (chan.exit_status, ''.join(out_all), ''.join(err_all))
[docs]def interactive_ssh_channel(chan, command=None, stdin=sys.stdin):
try:
stdin_is_tty = stdin.isatty()
except Exception:
stdin_is_tty = False
if stdin_is_tty:
oldtty = termios.tcgetattr(stdin)
chan.get_pty()
if command is not None:
chan.exec_command(command)
try:
if stdin_is_tty:
tty.setraw(stdin.fileno())
tty.setcbreak(stdin.fileno())
return CommandStatus(*drain_ssh_channel(chan, stdin))
finally:
if stdin_is_tty:
termios.tcsetattr(stdin, termios.TCSADRAIN, oldtty)
[docs]def json_dump(obj, f):
return json.dump(obj, f, indent=4)
[docs]def deepcopy(original_obj):
"""
Creates a deep copy of an object with no crossed referenced lists or dicts,
useful when loading from yaml as anchors generate those cross-referenced
dicts and lists
Args:
original_obj(object): Object to deep copy
Return:
object: deep copy of the object
"""
if isinstance(original_obj, list):
return list(deepcopy(item) for item in original_obj)
elif isinstance(original_obj, dict):
return dict((key, deepcopy(val)) for key, val in original_obj.items())
else:
return original_obj
[docs]def load_virt_stream(virt_fd):
"""
Loads the given conf stream into a dict, trying different formats if
needed
Args:
virt_fd (str): file like objcect with the virt config to load
Returns:
dict: Loaded virt config
"""
try:
virt_conf = json.load(virt_fd)
except ValueError:
virt_fd.seek(0)
virt_conf = yaml.load(virt_fd)
return deepcopy(virt_conf)
[docs]def in_prefix(prefix_class, workdir_class):
def decorator(func):
@functools.wraps(func)
def wrapper(*args, **kwargs):
prefix_path = kwargs.get('prefix_path', None)
workdir_path = kwargs.get('workdir_path', None)
if (
prefix_path is not None or (
prefix_class.is_prefix(os.curdir) and workdir_path is None
)
):
LOGGER.debug('Looking for a prefix')
prefix_path = prefix_class.resolve_prefix_path(prefix_path)
prefix = prefix_class(prefix_path)
kwargs['parent_workdir'] = None
else:
LOGGER.debug('Looking for a workdir')
if workdir_path is None:
workdir_path = 'auto'
workdir_path = workdir_class.resolve_workdir_path(workdir_path)
workdir = workdir_class(path=workdir_path)
kwargs['parent_workdir'] = workdir
if kwargs.get('all_envs', False):
prefix = workdir
else:
prefix_name = kwargs.get('prefix_name', 'current')
prefix = workdir.get_prefix(prefix_name)
kwargs['perfix_name'] = prefix_name
kwargs['prefix'] = prefix
return func(*args, **kwargs)
return wrapper
return decorator
[docs]def with_logging(func):
@functools.wraps(func)
def wrapper(prefix, *args, **kwargs):
setup_prefix_logging(prefix.paths.logs())
return func(*args, prefix=prefix, **kwargs)
return wrapper
