DPB VLAN system test case and pulled in VLAN related DVSLIB code

[vasant17]

What I did
Pulled in VLAN related DVSLIB files from an upstream PR in to this
Wrote VLAN DPB system test case using the CLI
Why I did it
To test VLAN dependency on DPB via CLI
How I verified it
By running the VS test case
Details if related

vapatil@server09:~/workspace/DPB/sonic-buildimage/src/sonic-swss/tests$ sudo pytest -s -v --pdb --dvsname=vs-jk test_port_dpb_system.py -k test_port_breakout_with_vlan
================================================================================== test session starts ==================================================================================
platform linux2 -- Python 2.7.17, pytest-3.3.0, py-1.8.0, pluggy-0.6.0 -- /usr/bin/python
cachedir: .cache
rootdir: /home/vapatil/workspace/DPB/sonic-buildimage/src/sonic-swss/tests, inifile:
collected 7 items                                                                                                                                                                       

test_port_dpb_system.py::TestPortDPBSystem::test_port_breakout_with_vlan remove extra link dummy
remove extra link Vlan100@Bridge
PASSED                                                                                                   [100%]

================================================================================== 6 tests deselected ===================================================================================
======================================================================= 1 passed, 6 deselected in 100.85 seconds ========================================================================

[praveen-li]

we can use before(bfrBreakOutMode) and after(afrBreakOutMode) too . Also, what about having one more test, where Say Ethernet4 is also part of same VLAN and an additional check is that if Ethernet4 not removed from VLAN.

[vasant17]

Agreed, we can make all different combinations and have lot more test cases. Some of them especially the one that you are describing is covered in test_port_dpb_vlan.py. Here all that I am covering is very basic VLAN dependency test case using CLI command. More will be covered while exercising other options of CLI comamnd.

[vasant17]

BTW, I did think about before and after breakout modes. But they do NOT make sense as I am also doing vice-versa.

[praveen-li]

any reason why this way of having many functions, is chosen instead of one function:

check_vlan_field(self, fvs, f, v):
assert fvs.get(f) == v

[vasant17]

As mentioned, these are the methods copied from several test_.py to here. To create one dvs_vlan.py, which uses dvslib_common functions.I will keep them as it for now.

[praveen-li]

LGTM, btw, plz click resolve conversation if making change\no change.