On 21.01.19 21:55, Eric Blake wrote:
> On 12/21/18 5:47 PM, Max Reitz wrote:
>> In some cases, we may want to deal with qemu-nbd errors (e.g. by
>> launching it in a different configuration until it no longer throws
>> any).  In that case, we do not want its output ending up in the test
>> output.
>>
>> It may still be useful for handling the error, though, so add a new
>> function that works basically like qemu_nbd(), only that it returns the
>> qemu-nbd output instead of making it end up in the log.  In contrast to
>> qemu_img_pipe(), it does still return the exit code as well, though,
> 
> In contrast to qemu_nbd(),

But qemu_nbd() does return the exit code.  qemu_img_pipe() doesn't.

>> because that is even more important for error handling.
>>
>> Signed-off-by: Max Reitz <mreitz@redhat.com>
>> ---
>>  tests/qemu-iotests/iotests.py | 14 ++++++++++++++
>>  1 file changed, 14 insertions(+)
>>
>> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
>> index d537538ba0..9c3eb9e2f8 100644
>> --- a/tests/qemu-iotests/iotests.py
>> +++ b/tests/qemu-iotests/iotests.py
>> @@ -190,6 +190,20 @@ def qemu_nbd(*args):
>>      '''Run qemu-nbd in daemon mode and return the parent's exit code'''
>>      return subprocess.call(qemu_nbd_args + ['--fork'] + list(args))
>>  
>> +def qemu_nbd_pipe(*args):
>> +    '''Run qemu-nbd in daemon mode and return both the parent's exit code
>> +       and its output'''
>> +    subp = subprocess.Popen(qemu_nbd_args + ['--fork'] + list(args),
>> +                            stdout=subprocess.PIPE,
>> +                            stderr=subprocess.STDOUT,
>> +                            universal_newlines=True)
>> +    exitcode = subp.wait()
>> +    if exitcode < 0:
>> +        sys.stderr.write('qemu-nbd received signal %i: %s\n' %
>> +                         (-exitcode,
>> +                          ' '.join(qemu_nbd_args + ['--fork'] + list(args))))
>> +    return exitcode, subp.communicate()[0]
>> +
> 
> Reviewed-by: Eric Blake <eblake@redhat.com>

Thanks for reviewing!

Max