Voltage and Current sensors CLI tests

[bmridul]

Description of PR

Sonic-mgmt tests for CLI introduced as part of Sensormon. HLD - sonic-net/SONiC#1394

Summary:
Added tests for Sensormon supported CLIs for
show platform voltage
show platform current

Type of change

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

Back port request

• 201911
• 202012
• 202205
• 202305

Approach

What is the motivation for this PR?

Added first set of sonic mgmt tests for Sensormon feature.

How did you verify/test it?

Ran the tests on the DUT.

Any platform specific information?

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

Any. Should be applicable to all.

Documentation

HLD link provided above.

[mssonicbld]

The pre-commit check detected issues in the files touched by this pull request.
The pre-commit check is a mandatory check, please fix detected issues.

Detailed pre-commit check results:
trim trailing whitespace.................................................Passed
fix end of files.........................................................Passed
check yaml...........................................(no files to check)Skipped
check for added large files..............................................Passed
check python ast.........................................................Failed
- hook id: check-ast
- exit code: 1

tests/platform_tests/cli/test_show_platform.py: failed parsing with CPython 3.8.10:

Traceback (most recent call last):
File "/home/AzDevOps/.cache/pre-commit/repoc03rpkpp/py_env-python3/lib/python3.8/site-packages/pre_commit_hooks/check_ast.py", line 21, in main
ast.parse(f.read(), filename=filename)
File "/usr/lib/python3.8/ast.py", line 47, in parse
return compile(source, filename, mode, flags,
File "tests/platform_tests/cli/test_show_platform.py", line 368
check_show_platform_sensor_output(cmd, duthost):
^
SyntaxError: invalid syntax
...
[truncated extra lines, please run pre-commit locally to view full check results]

To run the pre-commit checks locally, you can follow below steps:

1. Ensure that default python is python3. In sonic-mgmt docker container, default python is python2. You can run
   the check by activating the python3 virtual environment in sonic-mgmt docker container or outside of sonic-mgmt
   docker container.
2. Ensure that the pre-commit package is installed:

sudo pip install pre-commit

3. Go to repository root folder
4. Install the pre-commit hooks:

pre-commit install

5. Use pre-commit to check staged file:

pre-commit

6. Alternatively, you can check committed files using:

pre-commit run --from-ref <commit_id> --to-ref <commit_id>

[cyw233]

Hey @bmridul, could you sync this PR with the latest master as it's been here for quite a while, please? It's also a good chance to rerun the PR checks. Thanks!

[cyw233]

Wha is this : for? Is this a typo?

[cyw233]

What is hostname here and the ones in below? Should them be duthost.hostname?

[cyw233]

typo here, should be num_expected_cols

[cyw233]

Ditto the extra :

[cyw233]

Are we sure it's Not with a capital N? I think it'd better if we can lowercase raw_output_lines[0].strip() and then do the comparison, so we don't need to worry about the cases.

[spilkey-cisco]

Can this also check that the alarm status for every line of sensor data reads false, indicating no alarm? Perhaps test_thermal.py can instead be copied/expanded for coverage of sensors of other types (voltage, current, etc.)