- Why I did it
* To support systems with dynamic port configuration
* Apply lazy initialization to faster the speed of loading platform API
- How I did it
* Add module.py to implement dynamic port configuration (aka line card model)
* Adjust chassis.py, platform.py, thermal.py, sfp.py to support dynamic port configuration
* Optimize existing code
- How to verify it
Platform regression on MSN4700, MSN3800 and MSN2700, 100% pass
Unit test covers all new changes.
- Why I did it
Add NVIDIA Copyright header to "mellanox" files
- How I did it
Add NVIDIA Copyright header as a comment for Mellanox files
- How to verify it
Sanity tests and PR checkers.
- Why I did it
Remove EEPROM cache file and use DB instead
- How I did it
Read EEPROM data from DB if possible
If data is not ready in DB, read from hardware using a visitor pattern
- How to verify it
Manual test and regression
#### Why I did it
Recently, CLI sfputil replace the old sonic platform utils with sonic platform API. However, sonic platform API does not support SFP low power mode and reset related operation. The PR is to fix it.
The change to replace platform utils with sonic platform API was reverted on 202012, once this PR is merged, we can cherry-pick these two PRs to 202012 together.
#### How I did it
In low power mode and reset related operation, use "docker exec" if the command is running on host side.
