Add proxy support via environment variables

[apyrgio]

What is the feature and why do you need it:

Most programs detect that they must use a proxy by checking the http_proxy / https_proxy environment variables. See for example this section of requests on proxying: https://github.com/request/request#controlling-proxy-behaviour-using-environment-variables

This is not the case here though, as the user must explicitly override the .proxy argument of the Configuration class, in order to enable proxying.

python/kubernetes/client/configuration.py

Line 99 in b6e4ae8

self.proxy = None

Describe the solution you'd like to see:

The Configuration class should auto-detect the appropriate environment variables and pass them to urllib3, given that urllib3 has chosen not to do it (urllib3/urllib3#1785). If this proposal makes sense, I could open a PR.

[roycaihw]

The Configuration class is generated by openapi-generator: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/python/configuration.mustache. Could you file an issue in openapi-generator to propose adding the behavior?

[apyrgio]

Nice, thanks for pointing me to the template for this class.
So, I've opened an issue to OpenAPI (OpenAPITools/openapi-generator#6786). You can close this issue if you want to, or keep it open to track the progress of the OpenAPI issue.

[fejta-bot]

Issues go stale after 90d of inactivity.
Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle stale

[fejta-bot]

Stale issues rot after 30d of inactivity.
Mark the issue as fresh with /remove-lifecycle rotten.
Rotten issues close after an additional 30d of inactivity.

If this issue is safe to close now please do so with /close.

Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle rotten

[apyrgio]

Closing this issue since this is something that should be resolved on the OpenAPI side (I haven't done so yet though).