Make nat test less racy and accurate

Signed-off-by: Michael Crosby <crosbymichael@gmail.com>

integration-cli/docker_cli_nat_test.go

@@ -1,13 +1,11 @@
 package main
 
 import (
-	"encoding/json"
 	"fmt"
 	"net"
 	"os/exec"
+	"strings"
 	"testing"
-
-	"github.com/docker/docker/daemon"
 )
 
 func TestNetworkNat(t *testing.T) {
@@ -26,39 +24,23 @@ func TestNetworkNat(t *testing.T) {
 		t.Fatalf("Error retrieving the up for eth0: %s", err)
 	}
 
-	runCmd := exec.Command(dockerBinary, "run", "-d", "-p", "8080", "busybox", "nc", "-lp", "8080")
+	runCmd := exec.Command(dockerBinary, "run", "-dt", "-p", "8080:8080", "busybox", "nc", "-lp", "8080")
 	out, _, err := runCommandWithOutput(runCmd)
 	errorOut(err, t, fmt.Sprintf("run1 failed with errors: %v (%s)", err, out))
 
 	cleanedContainerID := stripTrailingCharacters(out)
 
-	inspectCmd := exec.Command(dockerBinary, "inspect", cleanedContainerID)
-	inspectOut, _, err := runCommandWithOutput(inspectCmd)
-	errorOut(err, t, fmt.Sprintf("out should've been a container id: %v %v", inspectOut, err))
-
-	containers := []*daemon.Container{}
-	if err := json.Unmarshal([]byte(inspectOut), &containers); err != nil {
-		t.Fatalf("Error inspecting the container: %s", err)
-	}
-	if len(containers) != 1 {
-		t.Fatalf("Unepexted container count. Expected 0, recieved: %d", len(containers))
-	}
-
-	port8080, exists := containers[0].NetworkSettings.Ports["8080/tcp"]
-	if !exists || len(port8080) == 0 {
-		t.Fatal("Port 8080/tcp not found in NetworkSettings")
-	}
-
-	runCmd = exec.Command(dockerBinary, "run", "-p", "8080", "busybox", "sh", "-c", fmt.Sprintf("echo hello world | nc -w 30 %s %s", ifaceIp, port8080[0].HostPort))
+	runCmd = exec.Command(dockerBinary, "run", "busybox", "sh", "-c", fmt.Sprintf("echo hello world | nc -w 30 %s 8080", ifaceIp))
 	out, _, err = runCommandWithOutput(runCmd)
 	errorOut(err, t, fmt.Sprintf("run2 failed with errors: %v (%s)", err, out))
 
 	runCmd = exec.Command(dockerBinary, "logs", cleanedContainerID)
 	out, _, err = runCommandWithOutput(runCmd)
 	errorOut(err, t, fmt.Sprintf("failed to retrieve logs for container: %v %v", cleanedContainerID, err))
+	out = strings.Trim(out, "\r\n")
 
-	if expected := "hello world\n"; out != expected {
-		t.Fatalf("Unexpected output. Expected: %s, recieved: -->%s<--", expected, out)
+	if expected := "hello world"; out != expected {
+		t.Fatalf("Unexpected output. Expected: %q, received: %q for iface %s", expected, out, ifaceIp)
 	}
 
 	killCmd := exec.Command(dockerBinary, "kill", cleanedContainerID)