Fix test_cont_link_flap

[bingwang-ms]

Signed-off-by: bingwang [email protected]

Description of PR

Summary:
Fixes # (issue)
Test case test_cont_link_flap consistently failed on master image. It was because recent update in show library made show ip route sum not availabe on lattest image. As a result, the command show ip route sum will not be able to retrieve routes count and an exception was thrown.

07/12/2020 17:51:39 INFO link_flap_utils.py:check_bgp_routes:195: IPv4 routes at end: 
07/12/2020 17:51:39 ERROR utilities.py:wait_until:43: Exception caught while checking check_bgp_routes: ValueError('could not convert string to float: ',)
07/12/2020 17:51:39 DEBUG utilities.py:wait_until:50: check_bgp_routes is False, wait 1 seconds and check again

This commit replaces 'show ip route sum' with vtysh command to fix the issue.

Type of change

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

Approach

What is the motivation for this PR?

This PR is to fix test_cont_link_flap on master image.

How did you do it?

This commit replaces show ip route sum with vtysh command to fix the issue.

How did you verify/test it?

Verified on DX010-4, running lattest image.

py.test --inventory ../ansible/str,../ansible/veos --host-pattern str-dx010-4 --module-path ../ansible --testbed vms7-t0-dx010-4 --testbed_file ../ansible/testbed.csv --junit-xml=tr.xml --log-cli-level warn --collect_techsupport=False --topology=t0,any,util  platform_tests/link_flap/test_cont_link_flap.py
========================================================================================= test session starts =========================================================================================
collected 1 item                                                                                                                                                                                      

platform_tests/link_flap/test_cont_link_flap.py::TestContLinkFlap::test_cont_link_flap ^@^@^@^@^@^@^@^@PASSED                                                                                                   [100%]

------------------------------------------------------------------ generated xml file: /data/Networking-acs-sonic-mgmt/tests/tr.xml -------------------------------------------------------------------
===================================================================================== 1 passed in 2664.16 seconds =====================================================================================

Any platform specific information?

No.

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

No.

Documentation

[yxieca]

can you wrap this in a help function to call "show ip route summary" first, if not successful, call the vtysh command to return the result?

[bingwang-ms]

Why do we need that? The show ip route is actually calling vtysh -c inside.

[yxieca]

We should use cli command whenever possible. not having the command is an image issue and it will be addressed.

[bingwang-ms]

Agree. So I think we should drop this PR and let the issue to surface out since they have confirmed that this is an image issue. What do you think?

[yxieca]

We can keep this PR. But put the work-around at a helper function that can be updated in the future would help.

[bingwang-ms]

If the workaround is added, how could we find such issue?

[bingwang-ms]

Closed. PR sonic-net/sonic-utilities#1302 addressed it.