From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41993) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dikoj-0007ei-7w for qemu-devel@nongnu.org; Fri, 18 Aug 2017 13:12:18 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dikog-0005iT-6e for qemu-devel@nongnu.org; Fri, 18 Aug 2017 13:12:17 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57264) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dikof-0005iB-U4 for qemu-devel@nongnu.org; Fri, 18 Aug 2017 13:12:14 -0400 From: Amador Pahim Date: Fri, 18 Aug 2017 19:05:17 +0200 Message-Id: <20170818170526.13496-3-apahim@redhat.com> In-Reply-To: <20170818170526.13496-1-apahim@redhat.com> References: <20170818170526.13496-1-apahim@redhat.com> Subject: [Qemu-devel] [PATCH v7 02/11] qemu.py: avoid writing to stdout/stderr List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: stefanha@gmail.com, famz@redhat.com, berrange@redhat.com, ehabkost@redhat.com, mreitz@redhat.com, kwolf@redhat.com, armbru@redhat.com, crosa@redhat.com, ldoktor@redhat.com, Amador Pahim This module should not write directly to stdout/stderr. Instead, it should either raise exceptions or just log the messages and let the callers handle them and decide what to do. For example, scripts could choose to send the log messages stderr or/and write them to a file if verbose or debugging mode is enabled. This patch replaces the writes to stderr by an exception in the send_fd_scm() when _socket_scm_helper is not set or not present. In the same method, the subprocess Popen will now redirect the stdout/stderr to logging.debug instead of writing to system stderr. As consequence, since the Popen.communicate() is now used (in order to get the stdout), the further call to wait() became redundant and was replaced by Popen.returncode. The shutdown() message on negative exit code will now be logged to logging.debug instead of written to system stderr. Signed-off-by: Amador Pahim --- scripts/qemu.py | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-) diff --git a/scripts/qemu.py b/scripts/qemu.py index 0ae5d39414..ef531bb23b 100644 --- a/scripts/qemu.py +++ b/scripts/qemu.py @@ -13,6 +13,7 @@ # import errno +import logging import string import os import sys @@ -20,6 +21,15 @@ import subprocess import qmp.qmp +LOG = logging.getLogger(__name__) + + +class QEMUMachineError(Exception): + """ + Exception called when an error in QEMUMachine happens. + """ + + class QEMUMachine(object): '''A QEMU VM''' @@ -62,18 +72,20 @@ class QEMUMachine(object): # In iotest.py, the qmp should always use unix socket. assert self._qmp.is_scm_available() if self._socket_scm_helper is None: - print >>sys.stderr, "No path to socket_scm_helper set" - return -1 + raise QEMUMachineError("No path to socket_scm_helper set") if os.path.exists(self._socket_scm_helper) == False: - print >>sys.stderr, "%s does not exist" % self._socket_scm_helper - return -1 + raise QEMUMachineError("%s does not exist" % self._socket_scm_helper) fd_param = ["%s" % self._socket_scm_helper, "%d" % self._qmp.get_sock_fd(), "%s" % fd_file_path] devnull = open('/dev/null', 'rb') - p = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout, - stderr=sys.stderr) - return p.wait() + p = subprocess.Popen(fd_param, stdin=devnull, stdout=subprocess.PIPE, + stderr=subprocess.STDOUT) + output = p.communicate()[0] + if output: + LOG.debug(output) + + return p.returncode @staticmethod def _remove_if_exists(path): @@ -154,7 +166,8 @@ class QEMUMachine(object): exitcode = self._popen.wait() if exitcode < 0: - sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode, ' '.join(self._args))) + LOG.debug('qemu received signal %i: %s', -exitcode, + ' '.join(self._args)) self._load_io_log() self._post_shutdown() -- 2.13.5