Continue logging failure to contact metadata url, fix conn leak.

pkg/kubelet/config/http.go

@@ -38,6 +38,7 @@ type sourceURL struct {
 	updates     chan<- interface{}
 	data        []byte
 	failureLogs int
+	client      *http.Client
 }
 
 func NewSourceURL(url string, header http.Header, nodeName string, period time.Duration, updates chan<- interface{}) {
@@ -47,6 +48,9 @@ func NewSourceURL(url string, header http.Header, nodeName string, period time.D
 		nodeName: nodeName,
 		updates:  updates,
 		data:     nil,
+		// Timing out requests leads to retries. This client is only used to
+		// read the the manifest URL passed to kubelet.
+		client: &http.Client{Timeout: 10 * time.Second},
 	}
 	glog.V(1).Infof("Watching URL %s", url)
 	go wait.Until(config.run, period, wait.NeverStop)
@@ -59,7 +63,9 @@ func (s *sourceURL) run() {
 		if s.failureLogs < 3 {
 			glog.Warningf("Failed to read pods from URL: %v", err)
 		} else if s.failureLogs == 3 {
-			glog.Warningf("Failed to read pods from URL. Won't log this message anymore: %v", err)
+			glog.Warningf("Failed to read pods from URL. Dropping verbosity of this message to V(4): %v", err)
+		} else {
+			glog.V(4).Infof("Failed to read pods from URL: %v", err)
 		}
 		s.failureLogs++
 	} else {
@@ -80,8 +86,7 @@ func (s *sourceURL) extractFromURL() error {
 		return err
 	}
 	req.Header = s.header
-	client := &http.Client{}
-	resp, err := client.Do(req)
+	resp, err := s.client.Do(req)
 	if err != nil {
 		return err
 	}

pkg/kubelet/config/http_test.go

@@ -44,7 +44,7 @@ func TestURLErrorNotExistNoUpdate(t *testing.T) {
 
 func TestExtractFromHttpBadness(t *testing.T) {
 	ch := make(chan interface{}, 1)
-	c := sourceURL{"http://localhost:49575/_not_found_", http.Header{}, "other", ch, nil, 0}
+	c := sourceURL{"http://localhost:49575/_not_found_", http.Header{}, "other", ch, nil, 0, http.DefaultClient}
 	if err := c.extractFromURL(); err == nil {
 		t.Errorf("Expected error")
 	}
@@ -114,7 +114,7 @@ func TestExtractInvalidPods(t *testing.T) {
 		// TODO: Uncomment when fix #19254
 		// defer testServer.Close()
 		ch := make(chan interface{}, 1)
-		c := sourceURL{testServer.URL, http.Header{}, "localhost", ch, nil, 0}
+		c := sourceURL{testServer.URL, http.Header{}, "localhost", ch, nil, 0, http.DefaultClient}
 		if err := c.extractFromURL(); err == nil {
 			t.Errorf("%s: Expected error", testCase.desc)
 		}
@@ -293,7 +293,7 @@ func TestExtractPodsFromHTTP(t *testing.T) {
 		// TODO: Uncomment when fix #19254
 		// defer testServer.Close()
 		ch := make(chan interface{}, 1)
-		c := sourceURL{testServer.URL, http.Header{}, hostname, ch, nil, 0}
+		c := sourceURL{testServer.URL, http.Header{}, hostname, ch, nil, 0, http.DefaultClient}
 		if err := c.extractFromURL(); err != nil {
 			t.Errorf("%s: Unexpected error: %v", testCase.desc, err)
 			continue
@@ -341,7 +341,7 @@ func TestURLWithHeader(t *testing.T) {
 	ch := make(chan interface{}, 1)
 	header := make(http.Header)
 	header.Set("Metadata-Flavor", "Google")
-	c := sourceURL{testServer.URL, header, "localhost", ch, nil, 0}
+	c := sourceURL{testServer.URL, header, "localhost", ch, nil, 0, http.DefaultClient}
 	if err := c.extractFromURL(); err != nil {
 		t.Fatalf("Unexpected error extracting from URL: %v", err)
 	}