Remove potential Goroutine leak in kubeadm wait.go

There are two writes yet only one read on a non-buffered channel that is
created locally and not passed anywhere else.

Therefore, it could leak one of its two spawned Goroutines if either:
* The provided `f` takes longer than an erroneous result from
  `waiter.WaitForHealthyKubelet`, or;
* The provided `f` completes before an erroneous result from
  `waiter.WaitForHealthyKubelet`.

The fix is to add a one-element buffer so that the channel write happens
for the second Goroutine in these cases, allowing it to finish and freeing
references to the now-buffered channel, letting it to be GC'd.
This commit is contained in:
Louis Jackman
2019-11-08 20:18:43 +00:00
committed by LouisJackman
parent bef8d426f2
commit 62e314a556

View File

@@ -157,7 +157,7 @@ func (w *KubeWaiter) WaitForHealthyKubelet(initalTimeout time.Duration, healthzE
// WaitForKubeletAndFunc waits primarily for the function f to execute, even though it might take some time. If that takes a long time, and the kubelet
// /healthz continuously are unhealthy, kubeadm will error out after a period of exponential backoff
func (w *KubeWaiter) WaitForKubeletAndFunc(f func() error) error {
errorChan := make(chan error)
errorChan := make(chan error, 1)
go func(errC chan error, waiter Waiter) {
if err := waiter.WaitForHealthyKubelet(40*time.Second, fmt.Sprintf("http://localhost:%d/healthz", kubeadmconstants.KubeletHealthzPort)); err != nil {