Merge pull request #58520 from porridge/fix-connreset

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>. Make IsConnectionReset work with more error implementations. **What this PR does / why we need it**: This fixes the code to correctly navigate error hierarchy, and actually work. **Which issue(s) this PR fixes** An improvement for #55860 **Special notes for your reviewer**: Integration-testing this code is somewhat hard. What I did to reproduce this condition reliably was: 1. use iptables to let the TCP handshake packets through but reject payload-carrying packets with: ``` sudo iptables -t raw -I PREROUTING -d localhost --protocol tcp --dport 443 -j NOTRACK sudo iptables -t filter -I INPUT -d localhost --protocol tcp --dport 443 -m string --algo bm --string http -j REJECT --reject-with tcp-reset ``` 2. start a dummy server with: `nc -l -4 localhost 443` 3. make the client issue a GET on localhost:443 Then I added instrumentation to the place in k8s.io/client-go/rest/request.go which calls this code, to discover the actual error hierarchy. I think another way to test this would be to run a dummy server which would listen() on a socket, accept() and then close() the incoming connection straight away. **Release note**: ```release-note Correctly handle transient connection reset errors on GET requests from client library. ```

Merge pull request #58520 from porridge/fix-connreset
c9c69013 · Kubernetes Submit Queue · GitHub · db8335f4 · 313128d7 · c9c69013
Unverified Commit c9c69013 authored Jan 20, 2018 by Kubernetes Submit Queue Committed by GitHub Jan 20, 2018
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Showing with 12 additions and 2 deletions

util.go staging/src/k8s.io/apimachinery/pkg/util/net/util.go +12 -2

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--- a/staging/src/k8s.io/apimachinery/pkg/util/net/util.go
+++ b/staging/src/k8s.io/apimachinery/pkg/util/net/util.go
@@ -18,6 +18,8 @@ package net
 import (
 	"net"
+	"net/url"
+	"os"
 	"reflect"
 	"syscall"
 )
@@ -38,8 +40,16 @@ func IPNetEqual(ipnet1, ipnet2 *net.IPNet) bool {
 // Returns if the given err is "connection reset by peer" error.
 func IsConnectionReset(err error) bool {
-	opErr, ok := err.(*net.OpError)
+	if urlErr, ok := err.(*url.Error); ok {
-	if ok && opErr.Err.Error() == syscall.ECONNRESET.Error() {
+		err = urlErr.Err
+	}
+	if opErr, ok := err.(*net.OpError); ok {
+		err = opErr.Err
+	}
+	if osErr, ok := err.(*os.SyscallError); ok {
+		err = osErr.Err
+	}
+	if errno, ok := err.(syscall.Errno); ok && errno == syscall.ECONNRESET {
 		return true
 	}
 	return false