Improve the refreshing of tokens from inside the cluster

[AlexisZam]

What type of PR is this?

kind/design

What this PR does / why we need it:

Requests from inside the cluster misuse the API to refresh tokens.

Which issue(s) this PR fixes:

Fixes #1948

Special notes for your reviewer:

Does this PR introduce a user-facing change?

NONE

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

[roycaihw]

/assign @yliaog

[yliaog]

thanks for the pr. is there a test to show the pr fixes the problem stated in the issue: #1948

[AlexisZam]

@yliaog This PR fixes a design problem, rather than a bug. As explained in #1948, the code works, but the API is misused. The proposed solution properly uses the API, and brings the in-cluster code in line with the out-of-cluster code.

Compare the in-cluster code:

python/kubernetes/base/config/incluster_config.py

Lines 95 to 100 in 392a8c1

	def _refresh_api_key(client_configuration):
	if self.token_expires_at <= datetime.datetime.now():
	self._read_token_file()
	self._set_config(client_configuration)
	client_configuration.refresh_api_key_hook = _refresh_api_key

and the out-of-cluster code:

python/kubernetes/base/config/kube_config.py

Lines 575 to 579 in 8f80cf4

	def _refresh_api_key(client_configuration):
	if ('expiry' in self.__dict__ and _is_expired(self.expiry)):
	self._load_authentication()
	self._set_config(client_configuration)
	client_configuration.refresh_api_key_hook = _refresh_api_key

[yliaog]

thanks.

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AlexisZam, yliaog

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