Suppress 'use of closed network connection' error in iowatcher

pkg/client/request.go

@@ -511,7 +511,9 @@ func (r *Request) Watch() (watch.Interface, error) {
 	}
 	resp, err := client.Do(req)
 	if err != nil {
-		if isProbableEOF(err) {
+		// The watch stream mechanism handles many common partial data errors, so closed
+		// connections can be retried in many cases.
+		if util.IsProbableEOF(err) {
 			return watch.NewEmptyWatch(), nil
 		}
 		return nil, err
@@ -525,25 +527,6 @@ 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
 // Any non-2xx http status code causes an error.  If we get a non-2xx code, we try to convert the body into an APIStatus object.

pkg/util/http.go

+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"io"
+	"net/url"
+	"strings"
+)
+
+// IsProbableEOF returns true if the given error resembles a connection termination
+// scenario that would justify assuming that the watch is empty.
+// These errors are what the Go http stack returns back to us which are general
+// connection closure errors (strongly correlated) and callers that need to
+// differentiate probable errors in connection behavior between normal "this is
+// disconnected" should use the method.
+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
+	case strings.Contains(strings.ToLower(err.Error()), "use of closed network connection"):
+		return true
+	}
+	return false
+}

pkg/watch/iowatcher.go

@@ -101,7 +101,12 @@ func (sw *StreamWatcher) receive() {
 			case io.ErrUnexpectedEOF:
 				glog.V(1).Infof("Unexpected EOF during watch stream event decoding: %v", err)
 			default:
-				glog.Errorf("Unable to decode an event from the watch stream: %v", err)
+				msg := "Unable to decode an event from the watch stream: %v"
+				if util.IsProbableEOF(err) {
+					glog.V(5).Infof(msg, err)
+				} else {
+					glog.Errorf(msg, err)
+				}
 			}
 			return
 		}