test_iface_loopback_action.py failed with TypeError: argument of type 'NoneType' is not iterable

[ZhaohuiS]

Description
3 cases for test_iface_loopback_action.py all failed at setup:

iface_loopback_action/test_iface_loopback_action.py::test_loopback_action_basic ERROR [ 33%]
iface_loopback_action/test_iface_loopback_action.py::test_loopback_action_port_flap ERROR [ 66%]
iface_loopback_action/test_iface_loopback_action.py::test_loopback_action_reload ERROR [100%]

It throws TypeError: argument of type 'NoneType' is not iterable

duthost    = <MultiAsicSonicHost bjw-can-2700-1>
ptf_ifaces = ['eth13', 'eth28', 'eth17', 'eth3', 'eth14', 'eth8', ...]
ptf_ifaces_map = {0: 'eth0', 1: 'eth1', 2: 'eth2', 3: 'eth3', ...}
ptf_port_mapping_mode = 'use_orig_interface'
ptfhost    = <tests.common.devices.ptf.PTFHost object at 0x7f9fd9837490>
request    = <SubRequest 'orig_ports_configuration' for <Function test_loopback_action_basic>>
res        = {'stderr_lines': [], u'cmd': [u'cat', u'/proc/net/dev'], u'end': u'2023-03-03 ...acts': {u'discovered_interpreter_python': u'/usr/bin/python'}, 'failed': False}
tbinfo     = {'auto_recover': 'True', 'comment': 'Beijing Lab', 'conf-name': 'testbed-bjw-can-2700-1', 'duts': ['bjw-can-2700-1'], ...}

iface_loopback_action/conftest.py:67: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
iface_loopback_action/iface_loopback_action_helper.py:113: in get_tested_up_ports
    port_dict['portchannel'] = get_portchannel_of_port(config_facts, port)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

config_facts = {'ACL_TABLE': {'DATAACL': {'policy_desc': u'DATAACL', 'ports': [u'PortChannel101', u'PortChannel102', u'PortChannel103...te_limit_interval': u'600', 'state': u'enabled'}, ...}, 'BGP_DEVICE_GLOBAL': {'STATE': {'tsa_enabled': u'false'}}, ...}
port = 'Ethernet8'

    def get_portchannel_of_port(config_facts, port):
        """
        Check if the port is a member of port channel, if it is then return the portchannel, else return Noe
        :param config_facts: DUT running config facts
        :param port: the port which need to check
        :return: portchannel or None
        """
        portchannels = config_facts['PORTCHANNEL'].keys() if 'PORTCHANNEL' in config_facts else []
        for portchannel in portchannels:
            portchannel_members = config_facts['PORTCHANNEL'][portchannel].get('members')
>           if port in portchannel_members:
E           TypeError: argument of type 'NoneType' is not iterable


config_facts = {'ACL_TABLE': {'DATAACL': {'policy_desc': u'DATAACL', 'ports': [u'PortChannel101', u'PortChannel102', u'PortChannel103...te_limit_interval': u'600', 'state': u'enabled'}, ...}, 'BGP_DEVICE_GLOBAL': {'STATE': {'tsa_enabled': u'false'}}, ...}
port       = 'Ethernet8'
portchannel = 'PortChannel104'
portchannel_members = None
portchannels = ['PortChannel104', 'PortChannel101', 'PortChannel103', 'PortChannel102']

iface_loopback_action/iface_loopback_action_helper.py:148: TypeError

Steps to reproduce the issue:

1. Load master image. "build_version": "master.227401-fffeec6ec", image file is here https://sonic-build.azurewebsites.net/ui/sonic/pipelines/139/builds/227401/artifacts?branchName=master
2. Run test_iface_loopback_action.py

Describe the results you received:

Describe the results you expected:

Additional information you deem important:

**Output of `show version`:**

```
(paste your output here)
```

**Attach debug file `sudo generate_dump`:**

```
(paste your output here)
```

[ZhaohuiS]

This issue could be fixed in #7668.
The failed reason is no member key under PORTCHANNEL in config_facts.

[bingwang-ms]

Fixed by #7668