watcher-decision-engine fails to start with python-ironicclient (4.0.0)

[Min Li]

I install the rokcy release of watcher, the watcher-decision-engine service fails to start, and the error is as follows:

exec watcher-decision-engine --config-file /etc/watcher/watcher.conf
Traceback (most recent call last):
  File "/usr/local/bin/watcher-decision-engine", line 6, in <module>
    from watcher.cmd.decisionengine import main
  File "/usr/local/lib/python2.7/dist-packages/watcher/cmd/decisionengine.py", line 28, in <module>
    from watcher.decision_engine import manager
  File "/usr/local/lib/python2.7/dist-packages/watcher/decision_engine/manager.py", line 41, in <module>
    from watcher.decision_engine.messaging import audit_endpoint
  File "/usr/local/lib/python2.7/dist-packages/watcher/decision_engine/messaging/audit_endpoint.py", line 24, in <module>
    from watcher.decision_engine.audit import continuous as c_handler
  File "/usr/local/lib/python2.7/dist-packages/watcher/decision_engine/audit/continuous.py", line 33, in <module>
    from watcher.decision_engine.audit import base
  File "/usr/local/lib/python2.7/dist-packages/watcher/decision_engine/audit/base.py", line 30, in <module>
    from watcher.decision_engine.strategy.context import default as default_context
  File "/usr/local/lib/python2.7/dist-packages/watcher/decision_engine/strategy/context/default.py", line 18, in <module>
    from watcher.common import clients
  File "/usr/local/lib/python2.7/dist-packages/watcher/common/clients.py", line 17, in <module>
    from ironicclient import client as irclient
  File "/usr/local/lib/python2.7/dist-packages/ironicclient/__init__.py", line 18, in <module>
    from ironicclient import client
  File "/usr/local/lib/python2.7/dist-packages/ironicclient/client.py", line 19, in <module>
    from ironicclient import exc
  File "/usr/local/lib/python2.7/dist-packages/ironicclient/exc.py", line 13, in <module>
    from ironicclient.common.apiclient import exceptions
  File "/usr/local/lib/python2.7/dist-packages/ironicclient/common/apiclient/exceptions.py", line 23, in <module>
    from http import client as http_client
ImportError: No module named http

I checked the python-ironicclient version ：python-ironicclient (4.0.0)

When I downgrade its version to 2.5.0, the service can start successfully.

[licanwei (li-canwei2)]

Hi,
for Rocky release, the version of python-ironicclient is 2.3.0 ~ 2.5.4[1],
so you can't install python-ironicclient (4.0.0) for Rocky.

[1]https://releases.openstack.org/rocky/index.html#rocky-python-ironicclient

[Min Li (limin0801)]

In fact, I install Rocky release of watcher from source, and automatically select the latest version of python-ironicclient (4.0.0) when execute `pip install -r requirements.txt`.
Therefore, I think that the version of python-ironicclient should be restricted in the requirements.txt.
Please see: https://review.opendev.org/#/c/720660/