Re: [Qemu-devel] [PATCH 4/5] iotests: Add @use_log to VM.run_job()

[John Snow <jsnow@redhat.com>]

On 6/27/19 6:32 PM, Max Reitz wrote:
> unittest-style tests generally do not use the log file, but VM.run_job()
> can still be useful to them.  Add a parameter to it that hides its
> output from the log file.
> 
> Signed-off-by: Max Reitz <mreitz@redhat.com>

Wondering out loud:

can log() (and by extension qmp_log, and run_job) be made to use the
python logging module and we can configure the logging environment
instead of bespoke arguments to avoid ever engaging the log?

We could theoretically just pre-disable iotests log output for unittest
style tests, unless you run in debug mode where we allow it.

I don't have a specific proposal for how to accomplish this, I think
there are some nuances to Python logging that I don't quite understand.
Maybe Cleber Rosa can help advise?

I'd like to toy with this idea; it seems like this won't be the last
time we want to turn output on/off.

--js

> ---
>  tests/qemu-iotests/iotests.py | 18 +++++++++++++-----
>  1 file changed, 13 insertions(+), 5 deletions(-)
> 
> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
> index 3ecef5bc90..ce74177ab1 100644
> --- a/tests/qemu-iotests/iotests.py
> +++ b/tests/qemu-iotests/iotests.py
> @@ -542,7 +542,7 @@ class VM(qtest.QEMUQtestMachine):
>  
>      # Returns None on success, and an error string on failure
>      def run_job(self, job, auto_finalize=True, auto_dismiss=False,
> -                pre_finalize=None, wait=60.0):
> +                pre_finalize=None, use_log=True, wait=60.0):
>          match_device = {'data': {'device': job}}
>          match_id = {'data': {'id': job}}
>          events = [
> @@ -557,7 +557,8 @@ class VM(qtest.QEMUQtestMachine):
>          while True:
>              ev = filter_qmp_event(self.events_wait(events))
>              if ev['event'] != 'JOB_STATUS_CHANGE':
> -                log(ev)
> +                if use_log:
> +                    log(ev)
>                  continue
>              status = ev['data']['status']
>              if status == 'aborting':
> @@ -565,13 +566,20 @@ class VM(qtest.QEMUQtestMachine):
>                  for j in result['return']:
>                      if j['id'] == job:
>                          error = j['error']
> -                        log('Job failed: %s' % (j['error']))
> +                        if use_log:
> +                            log('Job failed: %s' % (j['error']))
>              elif status == 'pending' and not auto_finalize:
>                  if pre_finalize:
>                      pre_finalize()
> -                self.qmp_log('job-finalize', id=job)
> +                if use_log:
> +                    self.qmp_log('job-finalize', id=job)
> +                else:
> +                    self.qmp('job-finalize', id=job)
>              elif status == 'concluded' and not auto_dismiss:
> -                self.qmp_log('job-dismiss', id=job)
> +                if use_log:
> +                    self.qmp_log('job-dismiss', id=job)
> +                else:
> +                    self.qmp('job-dismiss', id=job)
>              elif status == 'null':
>                  return error
>  
>