restructure the setup and teardown functions for network.py scripts (Bugfix)

[stanley31huang]

Description

There are some improvement in this PR as following:

1. restructure the setup and teardown functions with context manager library.
2. not bring up the network interfaces if it was down before testing.
3. not shutdown the conduit network interface (master network interface) while testing with an user network interface (slave network interface) (for Linux DSA network)

Resolved issues

#233
#401

Documentation

Reference:

• https://dri.freedesktop.org/docs/drm/networking/dsa/dsa.html
• https://www.kernel.org/doc/Documentation/ABI/testing/sysfs-class-net

Tests

Tested on system with multiple physical network

• all passed results:
  https://certification.canonical.com/hardware/202405-34042/submission/391153/
• eno3 network interface failed as expected (no ethernet cable connected), it's to simulate the test failed and make sure this scripts could restore the network configuration back.
  https://certification.canonical.com/hardware/202405-34042/submission/381308/

Tested on system with DSA network

• the lan2 network interface failed as expected, it's to simulate the iperf server is not stable and make sure this scripts could restore the network configuration back.
  https://certification.canonical.com/hardware/202405-34042/submission/381472/

[codecov]

Codecov Report

Attention: Patch coverage is 92.50000% with 9 lines in your changes missing coverage. Please review.

Project coverage is 45.99%. Comparing base (b92edc5) to head (8fac712).
Report is 132 commits behind head on main.

Files with missing lines	Patch %	Lines
providers/base/bin/network.py	92.50%	4 Missing and 5 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1342      +/-   ##
==========================================
+ Coverage   45.72%   45.99%   +0.26%     
==========================================
  Files         367      367              
  Lines       39134    39184      +50     
  Branches     6618     6629      +11     
==========================================
+ Hits        17894    18021     +127     
+ Misses      20565    20482      -83     
- Partials      675      681       +6     

Flag	Coverage Δ
provider-base	20.66% <91.66%> (+0.74%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[Hook25]

For me it is very hard to understand if this is ok actually, I have a few nitpicks about the code but nothing major. The submissions you provide actually have 2 failed tests, so I'm not sure what is going on there. Could this just randomly fail on some machines? Did you test on just two? Can you please test this on more? This is not ran during sru right?

(Oh and fantastic job with the context manager, I really like that!)

[stanley31huang]

For me it is very hard to understand if this is ok actually, I have a few nitpicks about the code but nothing major. The submissions you provide actually have 2 failed tests, so I'm not sure what is going on there.

Could this just randomly fail on some machines? Did you test on just two? Can you please test this on more?

I am sorry for the confusion on those failed test cases, it's trying to simulate some test failed scenario and make sure the network configuration could be restore. I have added more description for those submissions with failed tests, and attached a new submission without failed tests.

This is not ran during sru right?

I think so, it's not include in the SRU test plan as this is only include in the stress test plan.

(Oh and fantastic job with the context manager, I really like that!)