Python queue, 2017-09-15

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Merge remote-tracking branch 'remotes/ehabkost/tags/python-next-pull-request' into staging

Python queue, 2017-09-15

# gpg: Signature made Sat 16 Sep 2017 00:14:01 BST
# gpg:                using RSA key 0x2807936F984DC5A6
# gpg: Good signature from "Eduardo Habkost <ehabkost@redhat.com>"
# Primary key fingerprint: 5A32 2FD5 ABC4 D3DB ACCF  D1AA 2807 936F 984D C5A6

* remotes/ehabkost/tags/python-next-pull-request:
  qemu.py: include debug information on launch error
  qemu.py: improve message on negative exit code
  qemu.py: use os.path.null instead of /dev/null
  qemu.py: avoid writing to stdout/stderr
  qemu.py: fix is_running() return before first launch()
  qtest.py: Few pylint/style fixes
  qmp.py: Avoid overriding a builtin object
  qmp.py: Avoid "has_key" usage
  qmp.py: Use object-based class for QEMUMonitorProtocol
  qmp.py: Couple of pylint/style fixes
  qemu.py: Use custom exceptions rather than Exception
  qemu.py: Simplify QMP key-conversion
  qemu.py: Use iteritems rather than keys()
  qemu|qtest: Avoid dangerous arguments
  qemu.py: Pylint/style fixes

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Peter Maydell 2017-09-16 14:36:16 +01:00
commit 5ee53d1593
4 changed files with 154 additions and 63 deletions

View File

@ -13,13 +13,35 @@
# #
import errno import errno
import string import logging
import os import os
import sys import sys
import subprocess import subprocess
import qmp.qmp import qmp.qmp
LOG = logging.getLogger(__name__)
class QEMUMachineError(Exception):
"""
Exception called when an error in QEMUMachine happens.
"""
class MonitorResponseError(qmp.qmp.QMPError):
'''
Represents erroneous QMP monitor reply
'''
def __init__(self, reply):
try:
desc = reply["error"]["desc"]
except KeyError:
desc = reply
super(MonitorResponseError, self).__init__(desc)
self.reply = reply
class QEMUMachine(object): class QEMUMachine(object):
'''A QEMU VM '''A QEMU VM
@ -30,8 +52,26 @@ class QEMUMachine(object):
# vm is guaranteed to be shut down here # vm is guaranteed to be shut down here
''' '''
def __init__(self, binary, args=[], wrapper=[], name=None, test_dir="/var/tmp", def __init__(self, binary, args=None, wrapper=None, name=None,
monitor_address=None, socket_scm_helper=None, debug=False): test_dir="/var/tmp", monitor_address=None,
socket_scm_helper=None, debug=False):
'''
Initialize a QEMUMachine
@param binary: path to the qemu binary
@param args: list of extra arguments
@param wrapper: list of arguments used as prefix to qemu binary
@param name: prefix for socket and log file names (default: qemu-PID)
@param test_dir: where to create socket and log file
@param monitor_address: address for QMP monitor
@param socket_scm_helper: helper program, required for send_fd_scm()"
@param debug: enable debug mode
@note: Qemu process is not started until launch() is used.
'''
if args is None:
args = []
if wrapper is None:
wrapper = []
if name is None: if name is None:
name = "qemu-%d" % os.getpid() name = "qemu-%d" % os.getpid()
if monitor_address is None: if monitor_address is None:
@ -40,12 +80,14 @@ class QEMUMachine(object):
self._qemu_log_path = os.path.join(test_dir, name + ".log") self._qemu_log_path = os.path.join(test_dir, name + ".log")
self._popen = None self._popen = None
self._binary = binary self._binary = binary
self._args = list(args) # Force copy args in case we modify them self._args = list(args) # Force copy args in case we modify them
self._wrapper = wrapper self._wrapper = wrapper
self._events = [] self._events = []
self._iolog = None self._iolog = None
self._socket_scm_helper = socket_scm_helper self._socket_scm_helper = socket_scm_helper
self._debug = debug self._debug = debug
self._qmp = None
self._qemu_full_args = None
def __enter__(self): def __enter__(self):
return self return self
@ -76,18 +118,21 @@ class QEMUMachine(object):
# In iotest.py, the qmp should always use unix socket. # In iotest.py, the qmp should always use unix socket.
assert self._qmp.is_scm_available() assert self._qmp.is_scm_available()
if self._socket_scm_helper is None: if self._socket_scm_helper is None:
print >>sys.stderr, "No path to socket_scm_helper set" raise QEMUMachineError("No path to socket_scm_helper set")
return -1 if not os.path.exists(self._socket_scm_helper):
if os.path.exists(self._socket_scm_helper) == False: raise QEMUMachineError("%s does not exist" %
print >>sys.stderr, "%s does not exist" % self._socket_scm_helper self._socket_scm_helper)
return -1
fd_param = ["%s" % self._socket_scm_helper, fd_param = ["%s" % self._socket_scm_helper,
"%d" % self._qmp.get_sock_fd(), "%d" % self._qmp.get_sock_fd(),
"%s" % fd_file_path] "%s" % fd_file_path]
devnull = open('/dev/null', 'rb') devnull = open(os.path.devnull, 'rb')
p = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout, proc = subprocess.Popen(fd_param, stdin=devnull, stdout=subprocess.PIPE,
stderr=sys.stderr) stderr=subprocess.STDOUT)
return p.wait() output = proc.communicate()[0]
if output:
LOG.debug(output)
return proc.returncode
@staticmethod @staticmethod
def _remove_if_exists(path): def _remove_if_exists(path):
@ -100,7 +145,7 @@ class QEMUMachine(object):
raise raise
def is_running(self): def is_running(self):
return self._popen and (self._popen.returncode is None) return self._popen is not None and self._popen.returncode is None
def exitcode(self): def exitcode(self):
if self._popen is None: if self._popen is None:
@ -113,8 +158,8 @@ class QEMUMachine(object):
return self._popen.pid return self._popen.pid
def _load_io_log(self): def _load_io_log(self):
with open(self._qemu_log_path, "r") as fh: with open(self._qemu_log_path, "r") as iolog:
self._iolog = fh.read() self._iolog = iolog.read()
def _base_args(self): def _base_args(self):
if isinstance(self._monitor_address, tuple): if isinstance(self._monitor_address, tuple):
@ -128,7 +173,8 @@ class QEMUMachine(object):
'-display', 'none', '-vga', 'none'] '-display', 'none', '-vga', 'none']
def _pre_launch(self): def _pre_launch(self):
self._qmp = qmp.qmp.QEMUMonitorProtocol(self._monitor_address, server=True, self._qmp = qmp.qmp.QEMUMonitorProtocol(self._monitor_address,
server=True,
debug=self._debug) debug=self._debug)
def _post_launch(self): def _post_launch(self):
@ -141,13 +187,19 @@ class QEMUMachine(object):
def launch(self): def launch(self):
'''Launch the VM and establish a QMP connection''' '''Launch the VM and establish a QMP connection'''
devnull = open('/dev/null', 'rb') self._iolog = None
self._qemu_full_args = None
devnull = open(os.path.devnull, 'rb')
qemulog = open(self._qemu_log_path, 'wb') qemulog = open(self._qemu_log_path, 'wb')
try: try:
self._pre_launch() self._pre_launch()
args = self._wrapper + [self._binary] + self._base_args() + self._args self._qemu_full_args = self._wrapper + [self._binary] +
self._popen = subprocess.Popen(args, stdin=devnull, stdout=qemulog, self._base_args() + self._args
stderr=subprocess.STDOUT, shell=False) self._popen = subprocess.Popen(self._qemu_full_args,
stdin=devnull,
stdout=qemulog,
stderr=subprocess.STDOUT,
shell=False)
self._post_launch() self._post_launch()
except: except:
if self.is_running(): if self.is_running():
@ -155,6 +207,12 @@ class QEMUMachine(object):
self._popen.wait() self._popen.wait()
self._load_io_log() self._load_io_log()
self._post_shutdown() self._post_shutdown()
LOG.debug('Error launching VM')
if self._qemu_full_args:
LOG.debug('Command: %r', ' '.join(self._qemu_full_args))
if self._iolog:
LOG.debug('Output: %r', self._iolog)
raise raise
def shutdown(self): def shutdown(self):
@ -165,31 +223,42 @@ class QEMUMachine(object):
self._qmp.close() self._qmp.close()
except: except:
self._popen.kill() self._popen.kill()
self._popen.wait()
exitcode = self._popen.wait()
if exitcode < 0:
sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode, ' '.join(self._args)))
self._load_io_log() self._load_io_log()
self._post_shutdown() self._post_shutdown()
underscore_to_dash = string.maketrans('_', '-') exitcode = self.exitcode()
def qmp(self, cmd, conv_keys=True, **args): if exitcode is not None and exitcode < 0:
'''Invoke a QMP command and return the result dict''' msg = 'qemu received signal %i: %s'
qmp_args = dict() if self._qemu_full_args:
for k in args.keys(): command = ' '.join(self._qemu_full_args)
if conv_keys:
qmp_args[k.translate(self.underscore_to_dash)] = args[k]
else: else:
qmp_args[k] = args[k] command = ''
LOG.warn(msg, exitcode, command)
def qmp(self, cmd, conv_keys=True, **args):
'''Invoke a QMP command and return the response dict'''
qmp_args = dict()
for key, value in args.iteritems():
if conv_keys:
qmp_args[key.replace('_', '-')] = value
else:
qmp_args[key] = value
return self._qmp.cmd(cmd, args=qmp_args) return self._qmp.cmd(cmd, args=qmp_args)
def command(self, cmd, conv_keys=True, **args): def command(self, cmd, conv_keys=True, **args):
'''
Invoke a QMP command.
On success return the response dict.
On failure raise an exception.
'''
reply = self.qmp(cmd, conv_keys, **args) reply = self.qmp(cmd, conv_keys, **args)
if reply is None: if reply is None:
raise Exception("Monitor is closed") raise qmp.qmp.QMPError("Monitor is closed")
if "error" in reply: if "error" in reply:
raise Exception(reply["error"]["desc"]) raise MonitorResponseError(reply)
return reply["return"] return reply["return"]
def get_qmp_event(self, wait=False): def get_qmp_event(self, wait=False):
@ -207,7 +276,15 @@ class QEMUMachine(object):
return events return events
def event_wait(self, name, timeout=60.0, match=None): def event_wait(self, name, timeout=60.0, match=None):
# Test if 'match' is a recursive subset of 'event' '''
Wait for specified timeout on named event in QMP; optionally filter
results by match.
The 'match' is checked to be a recursive subset of the 'event'; skips
branch processing on match's value None
{"foo": {"bar": 1}} matches {"foo": None}
{"foo": {"bar": 1}} does not matches {"foo": {"baz": None}}
'''
def event_match(event, match=None): def event_match(event, match=None):
if match is None: if match is None:
return True return True
@ -240,4 +317,8 @@ class QEMUMachine(object):
return None return None
def get_log(self): def get_log(self):
'''
After self.shutdown or failed qemu execution, this returns the output
of the qemu process.
'''
return self._iolog return self._iolog

View File

@ -106,7 +106,7 @@ class FuzzyJSON(ast.NodeTransformer):
# _execute_cmd()). Let's design a better one. # _execute_cmd()). Let's design a better one.
class QMPShell(qmp.QEMUMonitorProtocol): class QMPShell(qmp.QEMUMonitorProtocol):
def __init__(self, address, pretty=False): def __init__(self, address, pretty=False):
qmp.QEMUMonitorProtocol.__init__(self, self.__get_address(address)) super(QMPShell, self).__init__(self.__get_address(address))
self._greeting = None self._greeting = None
self._completer = None self._completer = None
self._pretty = pretty self._pretty = pretty
@ -281,7 +281,7 @@ class QMPShell(qmp.QEMUMonitorProtocol):
return True return True
def connect(self, negotiate): def connect(self, negotiate):
self._greeting = qmp.QEMUMonitorProtocol.connect(self, negotiate) self._greeting = super(QMPShell, self).connect(negotiate)
self.__completer_setup() self.__completer_setup()
def show_banner(self, msg='Welcome to the QMP low-level shell!'): def show_banner(self, msg='Welcome to the QMP low-level shell!'):

View File

@ -13,19 +13,30 @@ import errno
import socket import socket
import sys import sys
class QMPError(Exception): class QMPError(Exception):
pass pass
class QMPConnectError(QMPError): class QMPConnectError(QMPError):
pass pass
class QMPCapabilitiesError(QMPError): class QMPCapabilitiesError(QMPError):
pass pass
class QMPTimeoutError(QMPError): class QMPTimeoutError(QMPError):
pass pass
class QEMUMonitorProtocol:
class QEMUMonitorProtocol(object):
#: Socket's error class
error = socket.error
#: Socket's timeout
timeout = socket.timeout
def __init__(self, address, server=False, debug=False): def __init__(self, address, server=False, debug=False):
""" """
Create a QEMUMonitorProtocol class. Create a QEMUMonitorProtocol class.
@ -42,6 +53,7 @@ class QEMUMonitorProtocol:
self.__address = address self.__address = address
self._debug = debug self._debug = debug
self.__sock = self.__get_sock() self.__sock = self.__get_sock()
self.__sockfile = None
if server: if server:
self.__sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) self.__sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.__sock.bind(self.__address) self.__sock.bind(self.__address)
@ -56,7 +68,7 @@ class QEMUMonitorProtocol:
def __negotiate_capabilities(self): def __negotiate_capabilities(self):
greeting = self.__json_read() greeting = self.__json_read()
if greeting is None or not greeting.has_key('QMP'): if greeting is None or "QMP" not in greeting:
raise QMPConnectError raise QMPConnectError
# Greeting seems ok, negotiate capabilities # Greeting seems ok, negotiate capabilities
resp = self.cmd('qmp_capabilities') resp = self.cmd('qmp_capabilities')
@ -78,8 +90,6 @@ class QEMUMonitorProtocol:
continue continue
return resp return resp
error = socket.error
def __get_events(self, wait=False): def __get_events(self, wait=False):
""" """
Check for new events in the stream and cache them in __events. Check for new events in the stream and cache them in __events.
@ -89,8 +99,8 @@ class QEMUMonitorProtocol:
@raise QMPTimeoutError: If a timeout float is provided and the timeout @raise QMPTimeoutError: If a timeout float is provided and the timeout
period elapses. period elapses.
@raise QMPConnectError: If wait is True but no events could be retrieved @raise QMPConnectError: If wait is True but no events could be
or if some other error occurred. retrieved or if some other error occurred.
""" """
# Check for new events regardless and pull them into the cache: # Check for new events regardless and pull them into the cache:
@ -167,38 +177,41 @@ class QEMUMonitorProtocol:
print >>sys.stderr, "QMP:<<< %s" % resp print >>sys.stderr, "QMP:<<< %s" % resp
return resp return resp
def cmd(self, name, args=None, id=None): def cmd(self, name, args=None, cmd_id=None):
""" """
Build a QMP command and send it to the QMP Monitor. Build a QMP command and send it to the QMP Monitor.
@param name: command name (string) @param name: command name (string)
@param args: command arguments (dict) @param args: command arguments (dict)
@param id: command id (dict, list, string or int) @param cmd_id: command id (dict, list, string or int)
""" """
qmp_cmd = { 'execute': name } qmp_cmd = {'execute': name}
if args: if args:
qmp_cmd['arguments'] = args qmp_cmd['arguments'] = args
if id: if cmd_id:
qmp_cmd['id'] = id qmp_cmd['id'] = cmd_id
return self.cmd_obj(qmp_cmd) return self.cmd_obj(qmp_cmd)
def command(self, cmd, **kwds): def command(self, cmd, **kwds):
"""
Build and send a QMP command to the monitor, report errors if any
"""
ret = self.cmd(cmd, kwds) ret = self.cmd(cmd, kwds)
if ret.has_key('error'): if "error" in ret:
raise Exception(ret['error']['desc']) raise Exception(ret['error']['desc'])
return ret['return'] return ret['return']
def pull_event(self, wait=False): def pull_event(self, wait=False):
""" """
Get and delete the first available QMP event. Pulls a single event.
@param wait (bool): block until an event is available. @param wait (bool): block until an event is available.
@param wait (float): If wait is a float, treat it as a timeout value. @param wait (float): If wait is a float, treat it as a timeout value.
@raise QMPTimeoutError: If a timeout float is provided and the timeout @raise QMPTimeoutError: If a timeout float is provided and the timeout
period elapses. period elapses.
@raise QMPConnectError: If wait is True but no events could be retrieved @raise QMPConnectError: If wait is True but no events could be
or if some other error occurred. retrieved or if some other error occurred.
@return The first available QMP event, or None. @return The first available QMP event, or None.
""" """
@ -217,8 +230,8 @@ class QEMUMonitorProtocol:
@raise QMPTimeoutError: If a timeout float is provided and the timeout @raise QMPTimeoutError: If a timeout float is provided and the timeout
period elapses. period elapses.
@raise QMPConnectError: If wait is True but no events could be retrieved @raise QMPConnectError: If wait is True but no events could be
or if some other error occurred. retrieved or if some other error occurred.
@return The list of available QMP events. @return The list of available QMP events.
""" """
@ -235,8 +248,6 @@ class QEMUMonitorProtocol:
self.__sock.close() self.__sock.close()
self.__sockfile.close() self.__sockfile.close()
timeout = socket.timeout
def settimeout(self, timeout): def settimeout(self, timeout):
self.__sock.settimeout(timeout) self.__sock.settimeout(timeout)

View File

@ -11,14 +11,11 @@
# Based on qmp.py. # Based on qmp.py.
# #
import errno
import socket import socket
import string
import os import os
import subprocess
import qmp.qmp
import qemu import qemu
class QEMUQtestProtocol(object): class QEMUQtestProtocol(object):
def __init__(self, address, server=False): def __init__(self, address, server=False):
""" """
@ -79,12 +76,14 @@ class QEMUQtestProtocol(object):
class QEMUQtestMachine(qemu.QEMUMachine): class QEMUQtestMachine(qemu.QEMUMachine):
'''A QEMU VM''' '''A QEMU VM'''
def __init__(self, binary, args=[], name=None, test_dir="/var/tmp", def __init__(self, binary, args=None, name=None, test_dir="/var/tmp",
socket_scm_helper=None): socket_scm_helper=None):
if name is None: if name is None:
name = "qemu-%d" % os.getpid() name = "qemu-%d" % os.getpid()
super(QEMUQtestMachine, self).__init__(binary, args, name=name, test_dir=test_dir, super(QEMUQtestMachine,
socket_scm_helper=socket_scm_helper) self).__init__(binary, args, name=name, test_dir=test_dir,
socket_scm_helper=socket_scm_helper)
self._qtest = None
self._qtest_path = os.path.join(test_dir, name + "-qtest.sock") self._qtest_path = os.path.join(test_dir, name + "-qtest.sock")
def _base_args(self): def _base_args(self):