Automatic merge from submit-queue (batch tested with PRs 38796, 40823, 40756, 41083, 41105)
Let ReadLogs return when there is a read error.
Fixes a bug in kuberuntime log.
Today, @yujuhong found that once we cancel `kubectl logs -f` with `Ctrl+C`, kuberuntime will keep complaining:
```
27939 kuberuntime_logs.go:192] Failed with err write tcp 10.240.0.4:10250->10.240.0.2:53913: write: broken pipe when writing log for log file "/var/log/pods/5bb76510-ed71-11e6-ad02-42010af00002/busybox_0.log": &{timestamp:{sec:63622095387 nsec:625309193 loc:0x484c440} stream:stdout log:[84 117 101 32 70 101 98 32 32 55 32 50 48 58 49 54 58 50 55 32 85 84 67 32 50 48 49 55 10]}
```
This is because kuberuntime keeps writing to the connection even though it is already closed. Actually, kuberuntime should return and report error whenever there is a writing error.
Ref the [docker code](3a4ae1f661/pkg/stdcopy/stdcopy.go (L159-L167))
I'm still creating the cluster and verifying this fix. Will post the result here after that.
/cc @yujuhong @kubernetes/sig-node-bugs
c6f30d3750