More unit test for configurable pod resolv.conf

pkg/kubelet/network/dns/dns_test.go

@@ -18,7 +18,9 @@ package dns
 
 import (
 	"fmt"
+	"io/ioutil"
 	"net"
+	"os"
 	"strings"
 	"testing"
 
@@ -487,64 +489,134 @@ func TestGetPodDNSCustom(t *testing.T) {
 		UID:       types.UID("testNode"),
 		Namespace: "",
 	}
-	clusterNS := "203.0.113.1"
+
+	testPodNamespace := "testNS"
+	testClusterNameserver := "10.0.0.10"
 	testClusterDNSDomain := "kubernetes.io"
-	testClusterDNS := []net.IP{net.ParseIP(clusterNS)}
+	testSvcDomain := fmt.Sprintf("svc.%s", testClusterDNSDomain)
-	testOptionValue := "3"
+	testNsSvcDomain := fmt.Sprintf("%s.svc.%s", testPodNamespace, testClusterDNSDomain)
+	testNdotsOptionValue := "3"
+	testHostNameserver := "8.8.8.8"
+	testHostDomain := "host.domain"
 
-	configurer := NewConfigurer(recorder, nodeRef, nil, testClusterDNS, testClusterDNSDomain, "")
+	testPod := &v1.Pod{
-
-	pod := &v1.Pod{
 		ObjectMeta: metav1.ObjectMeta{
-			UID:         "",
+			Name:      "test_pod",
-			Name:        "test_pod",
+			Namespace: testPodNamespace,
-			Namespace:   "testNS",
-			Annotations: map[string]string{},
 		},
-		Spec: v1.PodSpec{
-			DNSPolicy: v1.DNSClusterFirst,
-		},
-	}
-	clusterFirstDNSConfig, err := configurer.GetPodDNS(pod)
-	if err != nil {
-		t.Fatalf("Preparing clusterFirstDNSConfig: GetPodDNS(%v), unexpected error: %v", pod, err)
 	}
 
-	// Overwrite DNSPolicy for testing.
+	resolvConfContent := []byte(fmt.Sprintf("nameserver %s\nsearch %s\n", testHostNameserver, testHostDomain))
-	pod.Spec.DNSPolicy = v1.DNSNone
+	tmpfile, err := ioutil.TempFile("", "tmpResolvConf")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove(tmpfile.Name())
+	if _, err := tmpfile.Write(resolvConfContent); err != nil {
+		t.Fatal(err)
+	}
+	if err := tmpfile.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	configurer := NewConfigurer(recorder, nodeRef, nil, []net.IP{net.ParseIP(testClusterNameserver)}, testClusterDNSDomain, tmpfile.Name())
 
 	testCases := []struct {
 		desc                    string
 		customPodDNSFeatureGate bool
+		hostnetwork             bool
+		dnsPolicy               v1.DNSPolicy
 		dnsConfig               *v1.PodDNSConfig
 		expectedDNSConfig       *runtimeapi.DNSConfig
 	}{
 		{
-			desc:              "feature gate is disabled, DNSNone should fallback to DNSClusterFirst",
+			desc:      "feature gate is disabled, DNSNone should fallback to DNSClusterFirst",
-			expectedDNSConfig: clusterFirstDNSConfig,
+			dnsPolicy: v1.DNSNone,
+			expectedDNSConfig: &runtimeapi.DNSConfig{
+				Servers:  []string{testClusterNameserver},
+				Searches: []string{testNsSvcDomain, testSvcDomain, testClusterDNSDomain, testHostDomain},
+				Options:  []string{"ndots:5"},
+			},
 		},
 		{
 			desc: "feature gate is enabled, DNSNone without DNSConfig should have empty DNS settings",
 			customPodDNSFeatureGate: true,
+			dnsPolicy:               v1.DNSNone,
 			expectedDNSConfig:       &runtimeapi.DNSConfig{},
 		},
 		{
 			desc: "feature gate is enabled, DNSNone with DNSConfig should have a merged DNS settings",
 			customPodDNSFeatureGate: true,
+			dnsPolicy:               v1.DNSNone,
 			dnsConfig: &v1.PodDNSConfig{
-				Nameservers: []string{"10.0.0.10"},
+				Nameservers: []string{"203.0.113.1"},
 				Searches:    []string{"my.domain", "second.domain"},
 				Options: []v1.PodDNSConfigOption{
-					{Name: "ndots", Value: &testOptionValue},
+					{Name: "ndots", Value: &testNdotsOptionValue},
 					{Name: "debug"},
 				},
 			},
 			expectedDNSConfig: &runtimeapi.DNSConfig{
-				Servers:  []string{"10.0.0.10"},
+				Servers:  []string{"203.0.113.1"},
 				Searches: []string{"my.domain", "second.domain"},
 				Options:  []string{"ndots:3", "debug"},
 			},
 		},
+		{
+			desc: "feature gate is enabled, DNSClusterFirst with DNSConfig should have a merged DNS settings",
+			customPodDNSFeatureGate: true,
+			dnsPolicy:               v1.DNSClusterFirst,
+			dnsConfig: &v1.PodDNSConfig{
+				Nameservers: []string{"10.0.0.11"},
+				Searches:    []string{"my.domain"},
+				Options: []v1.PodDNSConfigOption{
+					{Name: "ndots", Value: &testNdotsOptionValue},
+					{Name: "debug"},
+				},
+			},
+			expectedDNSConfig: &runtimeapi.DNSConfig{
+				Servers:  []string{testClusterNameserver, "10.0.0.11"},
+				Searches: []string{testNsSvcDomain, testSvcDomain, testClusterDNSDomain, testHostDomain, "my.domain"},
+				Options:  []string{"ndots:3", "debug"},
+			},
+		},
+		{
+			desc: "feature gate is enabled, DNSClusterFirstWithHostNet with DNSConfig should have a merged DNS settings",
+			customPodDNSFeatureGate: true,
+			hostnetwork:             true,
+			dnsPolicy:               v1.DNSClusterFirstWithHostNet,
+			dnsConfig: &v1.PodDNSConfig{
+				Nameservers: []string{"10.0.0.11"},
+				Searches:    []string{"my.domain"},
+				Options: []v1.PodDNSConfigOption{
+					{Name: "ndots", Value: &testNdotsOptionValue},
+					{Name: "debug"},
+				},
+			},
+			expectedDNSConfig: &runtimeapi.DNSConfig{
+				Servers:  []string{testClusterNameserver, "10.0.0.11"},
+				Searches: []string{testNsSvcDomain, testSvcDomain, testClusterDNSDomain, testHostDomain, "my.domain"},
+				Options:  []string{"ndots:3", "debug"},
+			},
+		},
+		{
+			desc: "feature gate is enabled, DNSDefault with DNSConfig should have a merged DNS settings",
+			customPodDNSFeatureGate: true,
+			dnsPolicy:               v1.DNSDefault,
+			dnsConfig: &v1.PodDNSConfig{
+				Nameservers: []string{"10.0.0.11"},
+				Searches:    []string{"my.domain"},
+				Options: []v1.PodDNSConfigOption{
+					{Name: "ndots", Value: &testNdotsOptionValue},
+					{Name: "debug"},
+				},
+			},
+			expectedDNSConfig: &runtimeapi.DNSConfig{
+				Servers:  []string{testHostNameserver, "10.0.0.11"},
+				Searches: []string{testHostDomain, "my.domain"},
+				Options:  []string{"ndots:3", "debug"},
+			},
+		},
 	}
 
 	for _, tc := range testCases {
@@ -552,14 +624,16 @@ func TestGetPodDNSCustom(t *testing.T) {
 			t.Errorf("Failed to set CustomPodDNS feature gate: %v", err)
 		}
 
-		pod.Spec.DNSConfig = tc.dnsConfig
+		testPod.Spec.HostNetwork = tc.hostnetwork
+		testPod.Spec.DNSConfig = tc.dnsConfig
+		testPod.Spec.DNSPolicy = tc.dnsPolicy
 
-		resDNSConfig, err := configurer.GetPodDNS(pod)
+		resDNSConfig, err := configurer.GetPodDNS(testPod)
 		if err != nil {
-			t.Errorf("%s: GetPodDNS(%v), unexpected error: %v", tc.desc, pod, err)
+			t.Errorf("%s: GetPodDNS(%v), unexpected error: %v", tc.desc, testPod, err)
 		}
 		if !dnsConfigsAreEqual(resDNSConfig, tc.expectedDNSConfig) {
-			t.Errorf("%s: GetPodDNS(%v)=%v, want %v", tc.desc, pod, resDNSConfig, tc.expectedDNSConfig)
+			t.Errorf("%s: GetPodDNS(%v)=%v, want %v", tc.desc, testPod, resDNSConfig, tc.expectedDNSConfig)
 		}
 	}
 }