plugins/meta/portmap: add an iptables-based host port mapping plugin

plugins/meta/portmap/portmap_suite_test.go

@@ -0,0 +1,103 @@
+// Copyright 2017 CNI 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 main
+
+import (
+	"fmt"
+	"net"
+	"time"
+
+	"github.com/containernetworking/plugins/pkg/ns"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestPortmap(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "portmap Suite")
+}
+
+// OpenEchoServer opens a server that handles one connection before closing.
+// It opens on a random port and sends the port number on portChan when
+// the server is up and running. If an error is encountered, closes portChan.
+// If closeChan is closed, closes the socket.
+func OpenEchoServer(portChan chan<- int, closeChan <-chan interface{}) error {
+	laddr, err := net.ResolveTCPAddr("tcp", "0.0.0.0:0")
+	if err != nil {
+		close(portChan)
+		return err
+	}
+	sock, err := net.ListenTCP("tcp", laddr)
+	if err != nil {
+		close(portChan)
+		return err
+	}
+	defer sock.Close()
+
+	switch addr := sock.Addr().(type) {
+	case *net.TCPAddr:
+		portChan <- addr.Port
+	default:
+		close(portChan)
+		return fmt.Errorf("addr cast failed!")
+	}
+	for {
+		select {
+		case <-closeChan:
+			break
+		default:
+		}
+
+		sock.SetDeadline(time.Now().Add(time.Second))
+		con, err := sock.AcceptTCP()
+		if err != nil {
+			if opErr, ok := err.(*net.OpError); ok && opErr.Timeout() {
+				continue
+			}
+			continue
+		}
+
+		buf := make([]byte, 512)
+		con.Read(buf)
+		con.Write(buf)
+		con.Close()
+	}
+}
+
+func RunEchoServerInNS(netNS ns.NetNS) (int, chan interface{}, error) {
+	portChan := make(chan int)
+	closeChan := make(chan interface{})
+
+	go func() {
+		err := netNS.Do(func(ns.NetNS) error {
+			OpenEchoServer(portChan, closeChan)
+			return nil
+		})
+		// Somehow the ns.Do failed
+		if err != nil {
+			close(portChan)
+		}
+	}()
+
+	portNum := <-portChan
+	if portNum == 0 {
+		return 0, nil, fmt.Errorf("failed to execute server")
+	}
+
+	return portNum, closeChan, nil
+}