[Kimchi-devel] [PATCH V2] add a synchronous function with timeout to execute command

[Royce Lv]

On 2014年01月14日 10:29, Shu Ming wrote:
> It seems that python 3.3 has supported this function in a native way. 
> I think we can add some code to use the native one if it has like this
>
> import sys
> import subprocess
>
> def run_command(cmd, timeout=None):
>
> if sys.hexversion >= 0x03030000:
> return partial(subprocess.call, ...)
> else:
> ...
>
Agree, and I think our implementation can keep consistency with 3.3, so 
that caller can switch between them seamlessly.
> 2014/1/10 22:10, shaohef at linux.vnet.ibm.com:
>> From: ShaoHe Feng <shaohef at linux.vnet.ibm.com>
>>
>> We need a common function to execute shell command.
>> We also need timeout when execute shell command.
>>
>> A threading.Timer is used to send signal.SIGKILL to kill the command
>> when timeout.
>>
>> Signed-off-by: Royce Lv <lvroyce at linux.vnet.ibm.com>
>> Signed-off-by: ShaoHe Feng <shaohef at linux.vnet.ibm.com>
>> ---
>> src/kimchi/utils.py | 43 +++++++++++++++++++++++++++++++++++++++++++
>> 1 file changed, 43 insertions(+)
>>
>> diff --git a/src/kimchi/utils.py b/src/kimchi/utils.py
>> index af245c6..c7165ce 100644
>> --- a/src/kimchi/utils.py
>> +++ b/src/kimchi/utils.py
>> @@ -23,6 +23,7 @@
>>
>> import cherrypy
>> import os
>> +import subprocess
>> import urllib2
>>
>>
>> @@ -30,6 +31,7 @@ from cherrypy.lib.reprconf import Parser
>>
>>
>> from kimchi import config
>> +from threading import Timer
>>
>>
>> kimchi_log = cherrypy.log.error_log
>> @@ -96,3 +98,44 @@ def check_url_path(path):
>> return False
>>
>> return True
>> +
>> +
>> +def run_command(cmd, timeout=None):
>> + def kill_proc(proc, timeout_flag):
>> + timeout_flag[0] = True
>> + proc.kill()
>> +
>> + proc = None
>> + timer = None
>> + timeout_flag = [False]
>> +
>> + try:
>> + proc = subprocess.Popen(cmd, stdout=subprocess.PIPE,
>> + stderr=subprocess.PIPE)
>> + if timeout is not None:
>> + timer = Timer(timeout, kill_proc, [proc, timeout_flag])
>> + timer.start()
>> +
>> + out, error = proc.communicate()
>> + kimchi_log.debug("Run command: '%s'", " ".join(cmd))
>> +
>> + if out or error:
>> + kimchi_log.debug("out:\n %s\nerror:\n %s", out, error)
>> +
>> + if proc.returncode == -9 and timeout_flag[0] is True:
>> + kimchi_log.error("subprocess is killed by signal.SIGKILL "
>> + "for timeout %s seconds", timeout)
>> +
>> + return out, error, proc.returncode, timeout_flag[0]
>> + except Exception as e:
>> + msg = "Failed to run command: %s." % " ".join(cmd)
>> + msg = msg if proc is None else msg + "\n error code: %s."
>> + kimchi_log.error("%s\n %s", msg, e)
>> +
>> + if proc:
>> + return out, error, proc.returncode, timeout_flag[0]
>> + else:
>> + return None, None, None, timeout_flag[0]
>> + finally:
>> + if timer and not timeout_flag[0]:
>> + timer.cancel()
>
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