* Simplify port-forwarding code
Simplifies the establishment of a port-forwarding by moving the common
logic into `PortForward.Init()`
Stemmed from this
[comment](https://github.com/linkerd/linkerd2/pull/2937#discussion_r295078800)
Signed-off-by: Alejandro Pedraza <alejandro@buoyant.io>
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>
It's sometimes helpful to spotcheck proxy metrics from a specific pod,
but doing so with kubectl requires a few steps.
Introduce a new `linkerd metrics` command. When given a pod name and
namespace, returns a dump of the proxy's /metrics endpoint.
Also modify the k8s.portforward module to accept initialized k8s config
and client objects, to enable testing.
Fixes#2350.
Signed-off-by: Andrew Seigner <siggy@buoyant.io>
Alejandro Pedraza
Andrew Seigner
Andrew Seigner