Use a unix socket instead udp for reception of metrics (#2652)

internal/ingress/metric/collector/collector_test.go

@@ -0,0 +1,66 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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 collector
+
+import (
+	"fmt"
+	"net"
+	"sync/atomic"
+	"testing"
+	"time"
+)
+
+func TestNewUDPLogListener(t *testing.T) {
+	var count uint64
+
+	fn := func(message []byte) {
+		t.Logf("message: %v", string(message))
+		atomic.AddUint64(&count, 1)
+	}
+
+	tmpFile := fmt.Sprintf("/tmp/test-socket-%v", time.Now().Nanosecond())
+
+	l, err := net.Listen("unix", tmpFile)
+	if err != nil {
+		t.Fatalf("unexpected error creating unix socket: %v", err)
+	}
+	if l == nil {
+		t.Fatalf("expected a listener but none returned")
+	}
+
+	defer l.Close()
+
+	go func() {
+		for {
+			conn, err := l.Accept()
+			if err != nil {
+				continue
+			}
+
+			go handleMessages(conn, fn)
+		}
+	}()
+
+	conn, _ := net.Dial("unix", tmpFile)
+	conn.Write([]byte("message"))
+	conn.Close()
+
+	time.Sleep(1 * time.Millisecond)
+	if count != 1 {
+		t.Errorf("expected only one message from the UDP listern but %v returned", count)
+	}
+}