Fix DNS suffix search list issue for Windows container and workaround in kube-proxy.

pkg/proxy/winuserspace/BUILD

@@ -22,6 +22,8 @@ go_library(
     deps = [
         "//pkg/api:go_default_library",
         "//pkg/proxy:go_default_library",
+        "//pkg/util/exec:go_default_library",
+        "//pkg/util/ipconfig:go_default_library",
         "//pkg/util/netsh:go_default_library",
         "//pkg/util/slice:go_default_library",
         "//vendor:github.com/golang/glog",
@@ -35,6 +37,7 @@ go_test(
     name = "go_default_test",
     srcs = [
         "proxier_test.go",
+        "proxysocket_test.go",
         "roundrobin_test.go",
     ],
     library = ":go_default_library",

pkg/proxy/winuserspace/proxier.go

@@ -50,6 +50,7 @@ type serviceInfo struct {
 	socket              proxySocket
 	timeout             time.Duration
 	activeClients       *clientCache
+	dnsClients          *dnsClientCache
 	sessionAffinityType api.ServiceAffinity
 }
 
@@ -260,6 +261,7 @@ func (proxier *Proxier) addServicePortPortal(servicePortPortalName ServicePortPo
 		socket:              sock,
 		timeout:             timeout,
 		activeClients:       newClientCache(),
+		dnsClients:          newDnsClientCache(),
 		sessionAffinityType: api.ServiceAffinityNone, // default
 	}
 	proxier.setServiceInfo(servicePortPortalName, si)

pkg/proxy/winuserspace/proxysocket_test.go

+/*
+Copyright 2017 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 winuserspace
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestPackUnpackDnsMsgUnqualifiedName(t *testing.T) {
+	msg := &dnsMsg{}
+	var buffer [4096]byte
+
+	msg.header.id = 1
+	msg.header.qdCount = 1
+	msg.question = make([]dnsQuestion, msg.header.qdCount)
+	msg.question[0].qClass = 0x01
+	msg.question[0].qType = 0x01
+	msg.question[0].qName.name = "kubernetes"
+
+	length, ok := msg.packDnsMsg(buffer[:])
+	if !ok {
+		t.Errorf("Pack DNS message failed.")
+	}
+
+	unpackedMsg := &dnsMsg{}
+	if !unpackedMsg.unpackDnsMsg(buffer[:length]) {
+		t.Errorf("Unpack DNS message failed.")
+	}
+
+	if !reflect.DeepEqual(msg, unpackedMsg) {
+		t.Errorf("Pack and Unpack DNS message are not consistent.")
+	}
+}
+
+func TestPackUnpackDnsMsgFqdn(t *testing.T) {
+	msg := &dnsMsg{}
+	var buffer [4096]byte
+
+	msg.header.id = 1
+	msg.header.qdCount = 1
+	msg.question = make([]dnsQuestion, msg.header.qdCount)
+	msg.question[0].qClass = 0x01
+	msg.question[0].qType = 0x01
+	msg.question[0].qName.name = "kubernetes.default.svc.cluster.local"
+
+	length, ok := msg.packDnsMsg(buffer[:])
+	if !ok {
+		t.Errorf("Pack DNS message failed.")
+	}
+
+	unpackedMsg := &dnsMsg{}
+	if !unpackedMsg.unpackDnsMsg(buffer[:length]) {
+		t.Errorf("Unpack DNS message failed.")
+	}
+
+	if !reflect.DeepEqual(msg, unpackedMsg) {
+		t.Errorf("Pack and Unpack DNS message are not consistent.")
+	}
+}
+
+func TestPackUnpackDnsMsgEmptyName(t *testing.T) {
+	msg := &dnsMsg{}
+	var buffer [4096]byte
+
+	msg.header.id = 1
+	msg.header.qdCount = 1
+	msg.question = make([]dnsQuestion, msg.header.qdCount)
+	msg.question[0].qClass = 0x01
+	msg.question[0].qType = 0x01
+	msg.question[0].qName.name = ""
+
+	length, ok := msg.packDnsMsg(buffer[:])
+	if !ok {
+		t.Errorf("Pack DNS message failed.")
+	}
+
+	unpackedMsg := &dnsMsg{}
+	if !unpackedMsg.unpackDnsMsg(buffer[:length]) {
+		t.Errorf("Unpack DNS message failed.")
+	}
+
+	if !reflect.DeepEqual(msg, unpackedMsg) {
+		t.Errorf("Pack and Unpack DNS message are not consistent.")
+	}
+}
+
+func TestPackUnpackDnsMsgMultipleQuestions(t *testing.T) {
+	msg := &dnsMsg{}
+	var buffer [4096]byte
+
+	msg.header.id = 1
+	msg.header.qdCount = 2
+	msg.question = make([]dnsQuestion, msg.header.qdCount)
+	msg.question[0].qClass = 0x01
+	msg.question[0].qType = 0x01
+	msg.question[0].qName.name = "kubernetes"
+	msg.question[1].qClass = 0x01
+	msg.question[1].qType = 0x1c
+	msg.question[1].qName.name = "kubernetes.default"
+
+	length, ok := msg.packDnsMsg(buffer[:])
+	if !ok {
+		t.Errorf("Pack DNS message failed.")
+	}
+
+	unpackedMsg := &dnsMsg{}
+	if !unpackedMsg.unpackDnsMsg(buffer[:length]) {
+		t.Errorf("Unpack DNS message failed.")
+	}
+
+	if !reflect.DeepEqual(msg, unpackedMsg) {
+		t.Errorf("Pack and Unpack DNS message are not consistent.")
+	}
+}

pkg/util/BUILD

@@ -65,6 +65,7 @@ filegroup(
         "//pkg/util/interrupt:all-srcs",
         "//pkg/util/intstr:all-srcs",
         "//pkg/util/io:all-srcs",
+        "//pkg/util/ipconfig:all-srcs",
         "//pkg/util/iptables:all-srcs",
         "//pkg/util/json:all-srcs",
         "//pkg/util/keymutex:all-srcs",

pkg/util/ipconfig/BUILD

+package(default_visibility = ["//visibility:public"])
+
+licenses(["notice"])
+
+load(
+    "@io_bazel_rules_go//go:def.bzl",
+    "go_library",
+    "go_test",
+)
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "doc.go",
+        "ipconfig.go",
+    ],
+    tags = ["automanaged"],
+    deps = [
+        "//pkg/util/exec:go_default_library",
+        "//vendor:github.com/golang/glog",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["ipconfig_test.go"],
+    library = ":go_default_library",
+    tags = ["automanaged"],
+    deps = ["//pkg/util/exec:go_default_library"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+)

pkg/util/ipconfig/doc.go

+/*
+Copyright 2016 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 ipconfig provides an interface and implementations for running Windows ipconfig commands.
+package ipconfig // import "k8s.io/kubernetes/pkg/util/ipconfig"

pkg/util/ipconfig/ipconfig.go

+/*
+Copyright 2016 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 ipconfig
+
+import (
+	"runtime"
+	"strings"
+	"sync"
+
+	"github.com/golang/glog"
+
+	utilexec "k8s.io/kubernetes/pkg/util/exec"
+)
+
+// Interface is an injectable interface for running ipconfig commands.  Implementations must be goroutine-safe.
+type Interface interface {
+	// GetDnsSuffixSearchList returns the list of DNS suffix to search
+	GetDnsSuffixSearchList() ([]string, error)
+}
+
+const (
+	cmdIpconfig string = "ipconfig"
+
+	cmdDefaultArgs string = "/all"
+
+	dnsSuffixSearchLisLabel string = "DNS Suffix Search List"
+)
+
+// runner implements Interface in terms of exec("ipconfig").
+type runner struct {
+	mu   sync.Mutex
+	exec utilexec.Interface
+}
+
+// New returns a new Interface which will exec ipconfig.
+func New(exec utilexec.Interface) Interface {
+	runner := &runner{
+		exec: exec,
+	}
+	return runner
+}
+
+// GetDnsSuffixSearchList returns the list of DNS suffix to search
+func (runner *runner) GetDnsSuffixSearchList() ([]string, error) {
+	// Parse the DNS suffix search list from ipconfig output
+	// ipconfig /all on Windows displays the entry of DNS suffix search list
+	// An example output contains:
+	//
+	// DNS Suffix Search List. . . . . . : example1.com
+	//                                     example2.com
+	//
+	// TODO: this does not work when the label is localized
+	suffixList := []string{}
+	if runtime.GOOS != "windows" {
+		glog.V(1).Infof("ipconfig not supported on GOOS=%s", runtime.GOOS)
+		return suffixList, nil
+	}
+
+	out, err := runner.exec.Command(cmdIpconfig, cmdDefaultArgs).Output()
+
+	if err == nil {
+		lines := strings.Split(string(out), "\n")
+		for i, line := range lines {
+			if trimmed := strings.TrimSpace(line); strings.HasPrefix(trimmed, dnsSuffixSearchLisLabel) {
+				if parts := strings.Split(trimmed, ":"); len(parts) > 1 {
+					if trimmed := strings.TrimSpace(parts[1]); trimmed != "" {
+						suffixList = append(suffixList, strings.TrimSpace(parts[1]))
+					}
+					for j := i + 1; j < len(lines); j++ {
+						if trimmed := strings.TrimSpace(lines[j]); trimmed != "" && !strings.Contains(trimmed, ":") {
+							suffixList = append(suffixList, trimmed)
+						} else {
+							break
+						}
+					}
+				}
+				break
+			}
+		}
+	} else {
+		glog.V(1).Infof("Running %s %s failed: %v", cmdIpconfig, cmdDefaultArgs, err)
+	}
+
+	return suffixList, err
+}

pkg/util/ipconfig/ipconfig_test.go

+/*
+Copyright 2016 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 ipconfig
+
+import (
+	"testing"
+
+	"k8s.io/kubernetes/pkg/util/exec"
+)
+
+func TestGetDnsSuffixSearchList(t *testing.T) {
+	// Simple test
+	ipconfigInterface := New(exec.New())
+
+	_, err := ipconfigInterface.GetDnsSuffixSearchList()
+	if err != nil {
+		t.Errorf("expected success, got %v", err)
+	}
+}