Re: [PATCH v2 1/2] python: introduce qmp-shell-wrap convenience tool

["Daniel P. Berrangé" <berrange@redhat.com>]

On Tue, Jan 18, 2022 at 08:07:32PM -0500, John Snow wrote:
> On Tue, Jan 18, 2022 at 5:01 AM Daniel P. Berrangé <berrange@redhat.com> wrote:
> >
> > With the current 'qmp-shell' tool developers must first spawn QEMU with
> > a suitable -qmp arg and then spawn qmp-shell in a separate terminal
> > pointing to the right socket.
> >
> > With 'qmp-shell-wrap' developers can ignore QMP sockets entirely and
> > just pass the QEMU command and arguments they want. The program will
> > listen on a UNIX socket and tell QEMU to connect QMP to that.
> >
> > For example, this:
> >
> >  # qmp-shell-wrap -- qemu-system-x86_64 -display none
> >
> > Is roughly equivalent of running:
> >
> >  # qemu-system-x86_64 -display none -qmp qmp-shell-1234 &
> >  # qmp-shell qmp-shell-1234
> >
> > Except that 'qmp-shell-wrap' switches the socket peers around so that
> > it is the UNIX socket server and QEMU is the socket client. This makes
> > QEMU reliably go away when qmp-shell-wrap exits, closing the server
> > socket.
> >
> > Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
> 
> Thanks, I think this is pretty useful.
> 
> Can you look at setup.cfg and see about adding a qmp-shell-wrap entry
> point there? I had intended to wean people off of using /scripts for
> things that rely on the QMP packages, because I'm gonna fork them out
> and then these little forwards won't work without installing something
> anyway.

This looks simple enough but when I test I can't actuall get any of
the existing programs to work this way.

I did:

 $ python setup.py  install --user
 ...snip...
 Processing qemu-0.6.1.0a1-py3.10.egg
 Copying qemu-0.6.1.0a1-py3.10.egg to /home/berrange/.local/lib/python3.10/site-packages
 Adding qemu 0.6.1.0a1 to easy-install.pth file
 Installing aqmp-tui script to /home/berrange/.local/bin
 Installing qemu-ga-client script to /home/berrange/.local/bin
 Installing qmp-shell script to /home/berrange/.local/bin
 Installing qmp-shell-wrap script to /home/berrange/.local/bin
 Installing qom script to /home/berrange/.local/bin
 Installing qom-fuse script to /home/berrange/.local/bin
 Installing qom-get script to /home/berrange/.local/bin
 Installing qom-list script to /home/berrange/.local/bin
 Installing qom-set script to /home/berrange/.local/bin
 Installing qom-tree script to /home/berrange/.local/bin

 Installed /home/berrange/.local/lib/python3.10/site-packages/qemu-0.6.1.0a1-py3.10.egg
 Processing dependencies for qemu==0.6.1.0a1
 Finished processing dependencies for qemu==0.6.1.0a1


$ export PYTHONPATH=/home/berrange/.local/lib/python3.10/site-packages
$ qmp-shell
$ qmp-shell
Traceback (most recent call last):
  File "/home/berrange/.local/bin/qmp-shell", line 33, in <module>
    sys.exit(load_entry_point('qemu==0.6.1.0a1', 'console_scripts', 'qmp-shell')())
  File "/home/berrange/.local/bin/qmp-shell", line 25, in importlib_load_entry_point
    return next(matches).load()
  File "/usr/lib64/python3.10/importlib/metadata/__init__.py", line 162, in load
    module = import_module(match.group('module'))
  File "/usr/lib64/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 992, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 992, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1004, in _find_and_load_unlocked
ModuleNotFoundError: No module named 'qemu'

I can't see why this is failing to find 'qemu' when it exists fine:

$ python
>>> import qemu.aqmp.qmp_shell
>>> qemu.aqmp.qmp_shell.main()
usage: [-h] [-H] [-N] [-v] [-p] [-l LOGFILE] qmp_server
: error: the following arguments are required: qmp_server


Why is 'load_entry_point' unhappy ?

Regards,
Daniel
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