Python subprocess' CalledProcessError: Command '[...]' returns nonzero exit status 1

Question

Executing the following script ...

import socket                   
import sys                          

from collections import OrderedDict
from subprocess import check_output
from threading import Thread    

[...]

class IpCheck(Thread):  

    RECEIVED_PACKAGES_RE = re.compile(r'(\d+) received')

    def __init__(self, ip):                         
        Thread.__init__(self)
        self.ip = ip
        self.result = None

    def run(self):                          
        match = self.RECEIVED_PACKAGES_RE.search(
            check_output(['ping', '-q', '-c2', '-W1', self.ip])
        )

        successful_ping_count = int(match.group(1)) if match else 0

        if successful_ping_count == 0:
            self.result = 'no response'
        elif successful_ping_count == 1:
            self.result = 'alive, but 50% package loss'
        elif successful_ping_count == 2:
            self.result = check_snmp(self.ip)
        else:
            assert False

[...]

... results in an error:

CalledProcessError: the command '[ping', '-q', '-c2', '-W1', '10 .81.3.80 ']' returns nonzero exit status 1

Adding "stderr = STDOUT" to check_outputdid not bring any useful feedback.

How to get additional error information so that I can fix it?

Answer 1

subprocess.check_output CalledProcessError , ping , - (, , - ICMP - ).

, subprocess.Popen:

import subprocess
import sys

site = sys.argv[1]
ping_count = 4
process = subprocess.Popen(['ping', site, '-c', str(ping_count)],
                           stdout=subprocess.PIPE,
                           stderr=subprocess.STDOUT)
returncode = process.wait()
print('ping returned {0}'.format(returncode))
print(process.stdout.read())

:

$ python ping.py google.com         <-- ping successful
ping returned 0
PING google.com (195.64.213.27) 56(84) bytes of data.
64 bytes from cache.google.com (195.64.213.27): icmp_seq=1 ttl=57 time=59.8 ms
64 bytes from cache.google.com (195.64.213.27): icmp_seq=2 ttl=57 time=2.43 ms
64 bytes from cache.google.com (195.64.213.27): icmp_seq=3 ttl=57 time=77.0 ms
64 bytes from cache.google.com (195.64.213.27): icmp_seq=4 ttl=57 time=43.8 ms

--- google.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3004ms
rtt min/avg/max/mdev = 2.439/45.802/77.096/27.658 ms

$ python ping.py asdasdas.com       <-- DNS resolved, but site is down
ping returned 1
PING asdasdas.com (69.172.201.208) 56(84) bytes of data.

--- asdasdas.com ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3024ms

$ python ping.py asdasdasdasda.com  <-- DNS failed
ping returned 2
ping: unknown host asdasdasdasda.com

Answer 2

, ping . , , , IP- .

ping man- (http://linux.die.net/man/8/ping):

ping , 1. , , , , , 1. 2. 0. , , .

CalledProcessError , output. https://docs.python.org/2/library/subprocess.html#subprocess.check_output