Numerous codepaths have emerged that create k8s configs, k8s clients,
and make k8s api requests.
This branch consolidates k8s client creation and APIs. The primary
change migrates most codepaths to call `k8s.NewAPI` to instantiate a
`KubernetesAPI` struct from `pkg`. `KubernetesAPI` implements the
`kubernetes.Interface` (clientset) interface, and also persists a
`client-go` `rest.Config`.
Specific list of changes:
- removes manual GET requests from `k8s.KubernetesAPI`, in favor of
clientsets
- replaces most calls to `k8s.GetConfig`+`kubernetes.NewForConfig` with
a single `k8s.NewAPI`
- introduces a `timeout` param to `k8s.NewAPI`, currently only used by
healthchecks
- removes `NewClientSet` in `controller/k8s/clientset.go` in favor of
`k8s.NewAPI`
- removes `httpClient` and `clientset` from `HealthChecker`, use
`KubernetesAPI` instead
Signed-off-by: Andrew Seigner <siggy@buoyant.io>
Currently, cli/cmd/root.go provides a couple of utilities for building
clients to Linkerd's Public API; however these utilities are infallible,
execute health checks, etc.
There are a class of API clients---for instance, when an inject command
wants to acquire configuration from the API---where these checks are
undesirable. The version CLI built such a client, for example.
This change consolidates the various utilities into a single file.
Furthermore, it renames these utilities to clarify they differ.