[pytest] Add condition check to skip tests in unsupported topo.

[EmmaLin11]

Signed-off-by: Emma Lin emma_lin@edge-core.com

Description of PR

Summary:
Perform some tests in unsupported topology will failed.
Add condition check to skip tests in unsupported topology.

bgp_speaker: skip tests in t1 & ptf
bgp_fact: skip tests in ptf
dhcp_relay: skip tests in t1 & ptf
vrf: only support t0 topology, other topologies need to be filtered

Type of change

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

Approach

How did you do it?

Add condition check to skip tests in unsupported topo.

How did you verify/test it?

Perform pytest to confirm bgp_speaker/bgp_fact/dhcp_relay/vrf tests are skipped in unsupported topology.

Any platform specific information?

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

Documentation

[lguohan]

is this by design that vrf won't work for t0 topology?

[Minkang-Tsai]

Run vrf on t0 only.

[lguohan]

why use topo name here, not type?

[Minkang-Tsai]

Because we meet setup error on t0-56 as below

>       g_vars['vrf_intfs'] = get_vrf_intfs(cfg_facts)

test_vrf.py:426:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

cfg_facts = {'ACL_TABLE': {'DATAACL': {'policy_desc': 'DATAACL', 'ports': ['PortChannel0001', 'PortChannel0002', 'PortChannel0003'...BUFFER_POOL': {'ingress_lossy_pool': {'mode': 'dynamic', 'size': '32736769', 'type': 'ingress', 'xoff': '19457'}}, ...}

    def get_vrf_intfs(cfg_facts):
        intf_tables = ['INTERFACE', 'PORTCHANNEL_INTERFACE', 'VLAN_INTERFACE', 'LOOPBACK_INTERFACE']
        vrf_intfs = {}

        for table in intf_tables:
            for intf, attrs in cfg_facts.get(table, {}).iteritems():
                if '|' not in intf:
>                   vrf = attrs['vrf_name']
E                   KeyError: 'vrf_name'

test_vrf.py:115: KeyError

[lguohan]

the test should be fixed to support t0-56. you can open an issue to ask support vrf support in t0-56. but we should have uniform rule to decide whether a test can or cannot be run on certain topology. otherwise, the maintenance cost is too high.

[yxieca]

@linemma we will use markers to solve this issue at test execution level. Having test protect against topology again could be redundant.