This commit moves away from using a global variable for default
configuration checking, and instead exposes a method on LoadingRules to
determine whether a particular restclient.Config should be considered
"default". This allows kubectl to provide its own defaults (the same
as before, KUBERNETES_MASTER and the static localhost:8080 values) while
allowing other clients to avoid defining them.
In-cluster config defaulting is now easier to read.
Automatic merge from submit-queue
Fix clientcmd for a non-host cluster client running in a pod.
This is based on @errordeveloper's PR #32438. It fixes a case where default config is invalid and original config, i.e. `mergedConfig` is empty. It also adds a test for the case where default config is invalid and original config is neither invalid nor empty.
cc @errordeveloper @kubernetes/sig-cluster-federation @pwittrock @colhom
This is a follow on from the previous commit that fixed ClientConfig.
Namespace can also be defaulted from ICC, and this correctly handles
that logic. Also add two debugging lines to ensure that it is easier in
the future to uncover problems here.
By removing the default "localhost:8080" behavior several paths in
client config began returning err == ErrEmptyConfig rather than err ==
nil. The code checking for in cluster config was wrong - the logic
should be:
1. If loading the underlying config returns a non-empty error, fail
2. If the underlying config is not equal to the default config,
return that config (it's got user input)
3. If it is possible to use in cluster config, do so
4. Otherwise return the default config (and or default EmptyConfig
error).
