From 090b1a166bd19bdb98b0311d58b85582bd1676ed Mon Sep 17 00:00:00 2001 From: Rodolfo Alonso Hernandez Date: Wed, 8 Nov 2017 12:41:36 +0000 Subject: Replace subprocess "check_output" with "Popen" "check_output" is a blocking wrapper for "Popen" which returns the output of the command execution or raises an exception in case of error. "Popen" is a non-blocking function that allows to create asynchronous tasks. It returns any possible execution error but doesn't raise an exception; this is delegated to the developer. This code is used in the Yardstick CLI base test class. Change-Id: Ie3e1228b2d40cb306354447653678bf581bc9697 Signed-off-by: Rodolfo Alonso Hernandez --- yardstick/common/process.py | 91 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) (limited to 'yardstick/common/process.py') diff --git a/yardstick/common/process.py b/yardstick/common/process.py index 812ddea94..ede6cddac 100644 --- a/yardstick/common/process.py +++ b/yardstick/common/process.py @@ -11,10 +11,19 @@ # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. + import logging import multiprocessing +import signal +import subprocess +import time import os +from oslo_utils import encodeutils + +from yardstick.common import exceptions +from yardstick.common import utils + LOG = logging.getLogger(__name__) @@ -45,3 +54,85 @@ def terminate_children(timeout=3): for child in active_children: LOG.debug("%s %s %s, after terminate child: %s %s", current_proccess.name, current_proccess.pid, os.getpid(), child, child.pid) + + +def _additional_env_args(additional_env): + """Build arguments for adding additional environment vars with env""" + if additional_env is None: + return [] + return ['env'] + ['%s=%s' % pair for pair in additional_env.items()] + + +def _subprocess_setup(): + # Python installs a SIGPIPE handler by default. This is usually not what + # non-Python subprocesses expect. + signal.signal(signal.SIGPIPE, signal.SIG_DFL) + + +def subprocess_popen(args, stdin=None, stdout=None, stderr=None, shell=False, + env=None, preexec_fn=_subprocess_setup, close_fds=True): + return subprocess.Popen(args, shell=shell, stdin=stdin, stdout=stdout, + stderr=stderr, preexec_fn=preexec_fn, + close_fds=close_fds, env=env) + + +def create_process(cmd, run_as_root=False, additional_env=None): + """Create a process object for the given command. + + The return value will be a tuple of the process object and the + list of command arguments used to create it. + """ + if not isinstance(cmd, list): + cmd = [cmd] + cmd = list(map(str, _additional_env_args(additional_env) + cmd)) + if run_as_root: + # NOTE(ralonsoh): to handle a command executed as root, using + # a root wrapper, instead of using "sudo". + pass + LOG.debug("Running command: %s", cmd) + obj = subprocess_popen(cmd, shell=False, stdin=subprocess.PIPE, + stdout=subprocess.PIPE, stderr=subprocess.PIPE) + return obj, cmd + + +def execute(cmd, process_input=None, additional_env=None, + check_exit_code=True, return_stderr=False, log_fail_as_error=True, + extra_ok_codes=None, run_as_root=False): + try: + if process_input is not None: + _process_input = encodeutils.to_utf8(process_input) + else: + _process_input = None + + # NOTE(ralonsoh): to handle the execution of a command as root, + # using a root wrapper, instead of using "sudo". + obj, cmd = create_process(cmd, run_as_root=run_as_root, + additional_env=additional_env) + _stdout, _stderr = obj.communicate(_process_input) + returncode = obj.returncode + obj.stdin.close() + _stdout = utils.safe_decode_utf8(_stdout) + _stderr = utils.safe_decode_utf8(_stderr) + + extra_ok_codes = extra_ok_codes or [] + if returncode and returncode not in extra_ok_codes: + msg = ("Exit code: %(returncode)d; " + "Stdin: %(stdin)s; " + "Stdout: %(stdout)s; " + "Stderr: %(stderr)s") % {'returncode': returncode, + 'stdin': process_input or '', + 'stdout': _stdout, + 'stderr': _stderr} + if log_fail_as_error: + LOG.error(msg) + if check_exit_code: + raise exceptions.ProcessExecutionError(msg, + returncode=returncode) + + finally: + # This appears to be necessary in order for the subprocess to clean up + # something between call; without it, the second process hangs when two + # execute calls are made in a row. + time.sleep(0) + + return (_stdout, _stderr) if return_stderr else _stdout -- cgit 1.2.3-korg