From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:56632) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dt0C6-0005f0-UF for qemu-devel@nongnu.org; Fri, 15 Sep 2017 19:38:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dt0C5-0002aN-Q9 for qemu-devel@nongnu.org; Fri, 15 Sep 2017 19:38:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:51322) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dt0C5-0002Vw-IQ for qemu-devel@nongnu.org; Fri, 15 Sep 2017 19:38:45 -0400 From: Eduardo Habkost Date: Fri, 15 Sep 2017 20:37:36 -0300 Message-Id: <20170915233739.26860-13-ehabkost@redhat.com> In-Reply-To: <20170915233739.26860-1-ehabkost@redhat.com> References: <20170915233739.26860-1-ehabkost@redhat.com> Subject: [Qemu-devel] [PULL 12/15] qemu.py: avoid writing to stdout/stderr List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , qemu-devel@nongnu.org Cc: =?UTF-8?q?Luk=C3=A1=C5=A1=20Doktor?= , Stefan Hajnoczi , Amador Pahim From: 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.warn instead of written to system stderr. Signed-off-by: Amador Pahim Message-Id: <20170901112829.2571-3-apahim@redhat.com> Reviewed-by: Fam Zheng Signed-off-by: Eduardo Habkost --- scripts/qemu.py | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/scripts/qemu.py b/scripts/qemu.py index f80b008f7f..8d3d24dd2b 100644 --- a/scripts/qemu.py +++ b/scripts/qemu.py @@ -13,12 +13,22 @@ # import errno +import logging import os import sys import subprocess 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 @@ -107,18 +117,21 @@ 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 not os.path.exists(self._socket_scm_helper): - 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') - proc = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout, - stderr=sys.stderr) - return proc.wait() + proc = subprocess.Popen(fd_param, stdin=devnull, stdout=subprocess.PIPE, + stderr=subprocess.STDOUT) + output = proc.communicate()[0] + if output: + LOG.debug(output) + + return proc.returncode @staticmethod def _remove_if_exists(path): @@ -202,8 +215,8 @@ class QEMUMachine(object): exitcode = self._popen.wait() if exitcode < 0: - sys.stderr.write('qemu received signal %i: %s\n' - % (-exitcode, ' '.join(self._args))) + LOG.warn('qemu received signal %i: %s', -exitcode, + ' '.join(self._args)) self._load_io_log() self._post_shutdown() -- 2.13.5