fix: ignore unknown env vars

[matthewelwell]

Related to this issue.

The purpose is to prevent the application from hard crashing when unrecognised environment variables are provided.

[rolodato]

The error is not about unknown environment variables, it only happens if you try to use defined aliases

edge-proxy/src/edge_proxy/settings.py

Lines 119 to 121 in 6cde1e8

	validation_alias=AliasChoices(
	"api_poll_frequency_seconds",
	"api_poll_frequency",

[rolodato]

This is already the default per https://docs.pydantic.dev/latest/api/config/#pydantic.config.ConfigDict.extra

[matthewelwell]

Hmm... yes, but it's overridden specifically in the BaseSettings class as per this.

That being said, I expected (based on this) that something like docker run --rm -e FOO_BAR=foo flagsmith/edge-proxy:2.17.0 would also generate the error, but it didn't.

Probably more investigation is needed, although the solution I added here does prevent the error reported in the issue when using API_POLL_FREQUENCY, but perhaps it also has some other knock on effects that need investigating before (if) we merge this.

[matthewelwell]

I have tested the behaviour and verified that the code here does resolve the issue - it prevents the exception as well as behaving as expected if you to set API_POLL_FREQUENCY environment variable (or any other aliased name of a given setting).

I think we should go ahead and merge this.