kube-proxy: add --write-config flag

Add --write-config flag to kube-proxy to write the default configuration
values to the specified file location.

cmd/kube-proxy/app/server_test.go

@@ -18,15 +18,19 @@ package app
 
 import (
 	"fmt"
+	"reflect"
 	"runtime"
 	"strings"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/util/diff"
 	"k8s.io/kubernetes/pkg/api"
 	"k8s.io/kubernetes/pkg/apis/componentconfig"
+	"k8s.io/kubernetes/pkg/util"
 	"k8s.io/kubernetes/pkg/util/iptables"
 )
 
@@ -132,14 +136,17 @@ func Test_getProxyMode(t *testing.T) {
 
 // This test verifies that Proxy Server does not crash when CleanupAndExit is true.
 func TestProxyServerWithCleanupAndExit(t *testing.T) {
-	options := Options{
-		config: &componentconfig.KubeProxyConfiguration{
-			BindAddress: "0.0.0.0",
-		},
-		CleanupAndExit: true,
+	options, err := NewOptions()
+	if err != nil {
+		t.Fatal(err)
 	}
 
-	proxyserver, err := NewProxyServer(options.config, options.CleanupAndExit, options.master)
+	options.config = &componentconfig.KubeProxyConfiguration{
+		BindAddress: "0.0.0.0",
+	}
+	options.CleanupAndExit = true
+
+	proxyserver, err := NewProxyServer(options.config, options.CleanupAndExit, options.scheme, options.master)
 
 	assert.Nil(t, err)
 	assert.NotNil(t, proxyserver)
@@ -203,3 +210,82 @@ func TestGetConntrackMax(t *testing.T) {
 		}
 	}
 }
+
+func TestLoadConfig(t *testing.T) {
+	yaml := `apiVersion: componentconfig/v1alpha1
+bindAddress: 9.8.7.6
+clientConnection:
+  acceptContentTypes: "abc"
+  burst: 100
+  contentType: content-type
+  kubeconfig: "/path/to/kubeconfig"
+  qps: 7
+clusterCIDR: "1.2.3.0/24"
+configSyncPeriod: 15s
+conntrack:
+  max: 4
+  maxPerCore: 2
+  min: 1
+  tcpCloseWaitTimeout: 10s
+  tcpEstablishedTimeout: 20s
+featureGates: "all"
+healthzBindAddress: 1.2.3.4:12345
+hostnameOverride: "foo"
+iptables:
+  masqueradeAll: true
+  masqueradeBit: 17
+  minSyncPeriod: 10s
+  syncPeriod: 60s
+kind: KubeProxyConfiguration
+metricsBindAddress: 2.3.4.5:23456
+mode: "iptables"
+oomScoreAdj: 17
+portRange: "2-7"
+resourceContainer: /foo
+udpTimeoutMilliseconds: 123ms
+`
+
+	expected := &componentconfig.KubeProxyConfiguration{
+		BindAddress: "9.8.7.6",
+		ClientConnection: componentconfig.ClientConnectionConfiguration{
+			AcceptContentTypes: "abc",
+			Burst:              100,
+			ContentType:        "content-type",
+			KubeConfigFile:     "/path/to/kubeconfig",
+			QPS:                7,
+		},
+		ClusterCIDR:      "1.2.3.0/24",
+		ConfigSyncPeriod: metav1.Duration{Duration: 15 * time.Second},
+		Conntrack: componentconfig.KubeProxyConntrackConfiguration{
+			Max:                   4,
+			MaxPerCore:            2,
+			Min:                   1,
+			TCPCloseWaitTimeout:   metav1.Duration{Duration: 10 * time.Second},
+			TCPEstablishedTimeout: metav1.Duration{Duration: 20 * time.Second},
+		},
+		FeatureGates:       "all",
+		HealthzBindAddress: "1.2.3.4:12345",
+		HostnameOverride:   "foo",
+		IPTables: componentconfig.KubeProxyIPTablesConfiguration{
+			MasqueradeAll: true,
+			MasqueradeBit: util.Int32Ptr(17),
+			MinSyncPeriod: metav1.Duration{Duration: 10 * time.Second},
+			SyncPeriod:    metav1.Duration{Duration: 60 * time.Second},
+		},
+		MetricsBindAddress: "2.3.4.5:23456",
+		Mode:               "iptables",
+		OOMScoreAdj:        util.Int32Ptr(17),
+		PortRange:          "2-7",
+		ResourceContainer:  "/foo",
+		UDPIdleTimeout:     metav1.Duration{Duration: 123 * time.Millisecond},
+	}
+
+	options, err := NewOptions()
+	assert.NoError(t, err)
+
+	config, err := options.loadConfig([]byte(yaml))
+	assert.NoError(t, err)
+	if !reflect.DeepEqual(expected, config) {
+		t.Fatalf("unexpected config, diff = %s", diff.ObjectDiff(config, expected))
+	}
+}