[VS test stability] Chassis test

[prsunny]

The following tests starting consistently failing. Please analyze and fix.

2021-06-25T18:28:41.0688328Z test_virtual_chassis.py::TestVirtualChassis::test_chassis_app_db_sync FAILED [ 86%]
2021-06-25T18:28:51.5768542Z test_virtual_chassis.py::TestVirtualChassis::test_chassis_system_neigh FAILED [ 86%]
2021-06-25T18:29:02.0485211Z test_virtual_chassis.py::TestVirtualChassis::test_chassis_system_lag FAILED [ 87%]

Failure is here

More logs, artifacts for all three attempts could be found at:

https://dev.azure.com/mssonic/build/_build/results?buildId=21347&view=artifacts&pathAsName=false&type=publishedArtifacts

[prsunny]

@vganesan-nokia , @minionatwork , kindly prioritize this issue. Please email me, if you've further questions.

[prsunny]

It is temporarily skipped as part of #1809

[vganesan-nokia]

@vganesan-nokia , @minionatwork , kindly prioritize this issue. Please email me, if you've further questions.

The vs test for virtual chassis is broken due to problems introduced by couple of sonic-buildimage PRs merged on 06/23

(1) The changes from PR sonic-net/sonic-buildimage#7857 introduced problem in construction of config_db.json from /usr/share/sonic/virtual_chassis/default_config.json that is needed for VS virtual chassls tests.

(2) The fabricportlane mapping introduced by PR sonic-net/sonic-buildimage#7629. Along with this PR merging FABRIC_NUM_PORTS in conftest.py should be set to 16 (as stated in PR #1459)

I'll raise two PRs (one in sonic-buildimage and one in sonic-swss) to fix these.

[vganesan-nokia]

Fixed by the following two PRs:

sonic-swss: #1811
sonic-buildimage: sonic-net/sonic-buildimage#8008

These two PRs are dependent on each other. One of the PRs must be merged with known vs test_virtual_chassis.py failures reported in this issue.

[prsunny]

@vganesan-nokia , we also see it consistently failing for two other tests. Can you check if its due to any recent change in code.
#2004

[prsunny]

Please check this run for reference

[vganesan-nokia]

@prsunny, we have to enable the skipped tests in test_virtrual_chassis.py. These are enabled in PR #1811. This PR is yet to be merged.