Merge pull request #3037 from smarterclayton/hide_spurious_watch_errors

When connections are broken on Watch, write fewer errors to logs

pkg/client/request.go

@@ -25,6 +25,7 @@ import (
 	"net/url"
 	"path"
 	"strconv"
+	"strings"
 	"time"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
@@ -298,6 +299,9 @@ func (r *Request) Watch() (watch.Interface, error) {
 	}
 	resp, err := client.Do(req)
 	if err != nil {
+		if isProbableEOF(err) {
+			return watch.NewEmptyWatch(), nil
+		}
 		return nil, err
 	}
 	if resp.StatusCode != http.StatusOK {
@@ -310,6 +314,25 @@ func (r *Request) Watch() (watch.Interface, error) {
 	return watch.NewStreamWatcher(watchjson.NewDecoder(resp.Body, r.codec)), nil
 }
 
+// isProbableEOF returns true if the given error resembles a connection termination
+// scenario that would justify assuming that the watch is empty. The watch stream
+// mechanism handles many common partial data errors, so closed connections can be
+// retried in many cases.
+func isProbableEOF(err error) bool {
+	if uerr, ok := err.(*url.Error); ok {
+		err = uerr.Err
+	}
+	switch {
+	case err == io.EOF:
+		return true
+	case err.Error() == "http: can't write HTTP request on broken connection":
+		return true
+	case strings.Contains(err.Error(), "connection reset by peer"):
+		return true
+	}
+	return false
+}
+
 // Stream formats and executes the request, and offers streaming of the response.
 // Returns io.ReadCloser which could be used for streaming of the response, or an error
 func (r *Request) Stream() (io.ReadCloser, error) {