Add a test to check if pfcwd gets started after load_minigraph

[ZhaohuiS]

Signed-off-by: Zhaohui Sun zhaohuisun@microsoft.com

Description of PR

Summary:
Fixes # (issue)

Type of change

• Bug fix
• Testbed and Framework(new/improvement)
• Test case(new/improvement)

Back port request

• 201911

Approach

What is the motivation for this PR?

To fix #4740.
Add a test to check if pfcwd gets started after load_minigraph.

How did you do it?

Add a new test case test_default_cfg_after_load_mg, steps are:

1. Add a fixture to enable pfcwd configuration in init_cfg.json file.
2. run shell command: config load_minigraph -y
3. Check if pfcwd gets started with command: pfcwd show config

How did you verify/test it?

Run test case test_default_cfg_after_load_mg in tests/pfcwd/test_pfc_config.py.

Any platform specific information?

Supported testbed topology if it's a new test case?

Documentation

[antonptashnik]

@ZhaohuiS can you please say if default PFCWD config should be enabled on config reload ? I see the field default_pfcwd_status in config_db.json so I suspect it should be taken into account on config reload too to decide on PFCWD status. Thanks for the answer in advance!

[ZhaohuiS]

@ZhaohuiS can you please say if default PFCWD config should be enabled on config reload ? I see the field default_pfcwd_status in config_db.json so I suspect it should be taken into account on config reload too to decide on PFCWD status. Thanks for the answer in advance!

@antonptashnik I think in my case, I covered config load_minigraph to address #4740. It's probably better to check it for config reload as well, need the confirmation from @neethajohn