Deprecated CLI plugins

[sbesson]

Fixes #22 - see #23 for the previous attempt and #123 for a similar issue.

c81c3e6 ensures the plugins under omero/plugins are sorted before being loaded and registered as controls. 9160a88 renames the upload and metadata plugins as _upload_deprecated.py and _metadata_deprecated.py. This renaming should ensure the plugins are always loaded and registered first so that they can be overriden by another register_only call if the decoupled omero-metadata and omero-upload libraries are also installed.

This PR should be tested in a virtualenvironment in two steps

1. omero-py alone with no plugins installed

python3 -m venv venv
venv/bin/pip install git+git://github.com/snoopycrimecop/omero-py@py3_ci#egg=omero-py
venv/bin/omero upload foo # should display a deprecation warning
venv/bin/omero metadata -h  # should fail
OMERO_DEV_PLUGINS=true venv/bin/omero metadata -h # should display the help

2. omero-py with plugins installed

venv/bin/pip install git+git://github.com/snoopycrimecop/omero-metadata@py3_ci#egg=omero-metadata
venv/bin/pip install git+git://github.com/snoopycrimecop/omero-upload@py3_ci#egg=omero-upload
venv/bin/omero upload foo # should work without warnings
venv/bin/omero metadata -h  # should display the help message

[sbesson]

As suggested by ome/openmicroscopy#6183, the main breaking change associated with this proposal (or the alternate class removal) is that from omero.plugins.metadata would now unambiguously fail in an environment where only omero-py is installed but not omero-metadata.

[dominikl]

With omero-py alone, should OMERO_DEV_PLUGINS=true ./omero metadata ... not display the deprecation warning too?
After installing the plugins I get ModuleNotFoundError: No module named 'path'. For some reason that sounds familiar...

[dominikl]

I also still get the deprecation warning. Maybe I'm missing something...

(venv) ➜  bin pip freeze
future==0.18.2
omero-metadata==0.5.dev2
omero-py==5.6.dev6
omero-upload==0.3.dev2
Pillow==6.2.1
pkg-resources==0.0.0
PyYAML==5.1.2
zeroc-ice==3.6.5
(venv) ➜  bin ./omero upload test.txt
Error loading: /home/dominik/tmp/venv/lib/python3.6/site-packages/omero/plugins/upload.py
Traceback (most recent call last):
  File "/home/dominik/tmp/venv/lib/python3.6/site-packages/omero/cli.py", line 1657, in loadpath
    execfile(str(pathobj), loc)
  File "/home/dominik/tmp/venv/lib/python3.6/site-packages/past/builtins/misc.py", line 87, in execfile
    exec_(code, myglobals, mylocals)
  File "/home/dominik/tmp/venv/lib/python3.6/site-packages/omero/plugins/upload.py", line 17, in <module>
    from omero_upload.cli import UploadControl, HELP
  File "/home/dominik/tmp/venv/lib/python3.6/site-packages/omero_upload/cli.py", line 23, in <module>
    import path
ModuleNotFoundError: No module named 'path'
This module is deprecated as of OMERO 5.5.0. Use the module available from https://pypi.org/project/omero-upload/ instead.
Previously logged in to merge-ci-devspace.openmicroscopy.org:4064 as user-3
...

[sbesson]

With omero-py alone, should OMERO_DEV_PLUGINS=true ./omero metadata ... not display the deprecation warning too?

You are correct, both deprecated plugins should display the same message to end users, I will look into adding some message.

After installing the plugins I get ModuleNotFoundError: No module named 'path'. For some reason that sounds familiar...

That's related to #123. The same exception handling as in ome/omero-dropbox#8 will need to be opened against omero_upload.
I suspect the last error you are seeing is because the omero_upload import fails due to path/omero_ext.path and thus bin ./omero upload test.txt falls back to the deprecated upload plugin.

[will-moore]

All working exactly as described in the description. 👍

[joshmoore]

Thanks, all.