fix: Reading env file when running project locally without docker

[hirensoni913]

SUMMARY

Imported load_dotenv in config.py to read the .env file

BEFORE/AFTER SCREENSHOTS OR ANIMATED GIF

TESTING INSTRUCTIONS

ADDITIONAL INFORMATION

• Has associated issue:
• Required feature flags:
• Changes UI
• Includes DB Migration (follow approval process in SIP-59)
  • Migration is atomic, supports rollback & is backwards-compatible
  • Confirm DB migration upgrade and downgrade tested
  • Runtime estimates and downtime expectations provided
• Introduces new feature or API
• Removes existing feature or API

[github-actions]

Congrats on making your first PR and thank you for contributing to Superset! 🎉 ❤️

We hope to see you in our Slack community too! Not signed up? Use our Slack App to self-register.

[rusackas]

LGTM, but pinging @mistercrunch in case he knows of some intricacy I don't :) Thanks for opening this!

[codecov]

Codecov Report

Attention: Patch coverage is 80.00000% with 1 line in your changes missing coverage. Please review.

Project coverage is 83.66%. Comparing base (76d897e) to head (1d9fda8).
Report is 414 commits behind head on master.

Files	Patch %	Lines
superset/config.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           master   #29471       +/-   ##
===========================================
+ Coverage   60.48%   83.66%   +23.18%     
===========================================
  Files        1931      521     -1410     
  Lines       76236    37494    -38742     
  Branches     8568        0     -8568     
===========================================
- Hits        46114    31371    -14743     
+ Misses      28017     6123    -21894     
+ Partials     2105        0     -2105     

Flag	Coverage Δ
hive	49.06% <80.00%> (-0.11%)	⬇️
javascript	?
postgres	77.11% <80.00%> (?)
presto	53.67% <80.00%> (-0.13%)	⬇️
python	83.66% <80.00%> (+20.18%)	⬆️
sqlite	76.58% <80.00%> (?)
unit	59.64% <80.00%> (+2.01%)	⬆️

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.

[rusackas]

Looks like you'll need to run the pre-commit hook to make the linters happy.

[mistercrunch]

Could this potentially be a breaking change in some environments?

I checked that traditionally-set env vars take precedence over .env files here, but there may be a small risk of envrionments where:

1. a [previously unused] .env file exists - maybe some service template at some companies lay a default .env file for all services
2. .env file happens to set something that's not desired / causes a change of behavior

Another potential issue would be around docker-compose and the .env that already exist in the docker/ folder, and just want to make sure that this shouldn't be a problem there either. I can't think of anything but could see edge cases there.

Given issues are super unlikely, I'd like to push this forward, but would like to first:

• add a note in UPDATING.md giving a heads-up to people performing upgrades. Typically they would know whether this might create a change of behavior in their env
• add a note in our docs, letting users know that we support .env files

More generally it would be great for our config system to support more env vars, especially for simple / str parameters, maybe for an approved list of parameter and with a clear prefix, as in SUPERSET__SQLALCHEMY_EXAMPLES_URI. I think this should be a matter of creating a list of params that support this, and for-loop over it while checking for env vars fitting the pattern. + maybe a bit of smart casting to also support boolean, int, maybe even json if we were feeling fancy