test ipvs proxy mode when feature gateway set

cmd/kube-proxy/app/server_test.go

@@ -28,8 +28,10 @@ import (
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/diff"
+	utilfeature "k8s.io/apiserver/pkg/util/feature"
 	api "k8s.io/kubernetes/pkg/apis/core"
 	"k8s.io/kubernetes/pkg/proxy/apis/kubeproxyconfig"
+	"k8s.io/kubernetes/pkg/proxy/ipvs"
 	"k8s.io/kubernetes/pkg/util/configz"
 	"k8s.io/kubernetes/pkg/util/iptables"
 	utilpointer "k8s.io/kubernetes/pkg/util/pointer"
@@ -175,6 +177,138 @@ func Test_getProxyMode(t *testing.T) {
 	}
 }
 
+// This is a coarse test, but it offers some modicum of confidence as the code is evolved.
+func Test_getProxyModeEnableFeatureGateway(t *testing.T) {
+	if runtime.GOOS != "linux" {
+		t.Skip("skipping on non-Linux")
+	}
+
+	// enable IPVS feature gateway
+	utilfeature.DefaultFeatureGate.Set("SupportIPVSProxyMode=true")
+
+	var cases = []struct {
+		flag            string
+		iptablesVersion string
+		ipsetVersion    string
+		kernelCompat    bool
+		iptablesError   error
+		ipsetError      error
+		mods            []string
+		expected        string
+	}{
+		{ // flag says userspace
+			flag:     "userspace",
+			expected: proxyModeUserspace,
+		},
+		{ // flag says iptables, error detecting version
+			flag:          "iptables",
+			iptablesError: fmt.Errorf("oops!"),
+			expected:      proxyModeUserspace,
+		},
+		{ // flag says iptables, version too low
+			flag:            "iptables",
+			iptablesVersion: "0.0.0",
+			expected:        proxyModeUserspace,
+		},
+		{ // flag says iptables, version ok, kernel not compatible
+			flag:            "iptables",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    false,
+			expected:        proxyModeUserspace,
+		},
+		{ // flag says iptables, version ok, kernel is compatible
+			flag:            "iptables",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    true,
+			expected:        proxyModeIPTables,
+		},
+		{ // detect, error
+			flag:          "",
+			iptablesError: fmt.Errorf("oops!"),
+			expected:      proxyModeUserspace,
+		},
+		{ // detect, version too low
+			flag:            "",
+			iptablesVersion: "0.0.0",
+			expected:        proxyModeUserspace,
+		},
+		{ // detect, version ok, kernel not compatible
+			flag:            "",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    false,
+			expected:        proxyModeUserspace,
+		},
+		{ // detect, version ok, kernel is compatible
+			flag:            "",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    true,
+			expected:        proxyModeIPTables,
+		},
+		{ // detect, version ok, kernel is compatible
+			flag:            "",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    true,
+			expected:        proxyModeIPTables,
+		},
+		{ // flag says ipvs, ipset version ok, kernel modules installed
+			flag:         "ipvs",
+			mods:         []string{"ip_vs", "ip_vs_rr", "ip_vs_wrr", "ip_vs_sh", "nf_conntrack_ipv4"},
+			ipsetVersion: ipvs.MinIPSetCheckVersion,
+			expected:     proxyModeIPVS,
+		},
+		{ // flag says ipvs, ipset version too low, fallback on iptables mode
+			flag:            "ipvs",
+			mods:            []string{"ip_vs", "ip_vs_rr", "ip_vs_wrr", "ip_vs_sh", "nf_conntrack_ipv4"},
+			ipsetVersion:    "0.0",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    true,
+			expected:        proxyModeIPTables,
+		},
+		{ // flag says ipvs, bad ipset version, fallback on iptables mode
+			flag:            "ipvs",
+			mods:            []string{"ip_vs", "ip_vs_rr", "ip_vs_wrr", "ip_vs_sh", "nf_conntrack_ipv4"},
+			ipsetVersion:    "a.b.c",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    true,
+			expected:        proxyModeIPTables,
+		},
+		{ // flag says ipvs, required kernel modules are not installed, fallback on iptables mode
+			flag:            "ipvs",
+			mods:            []string{"foo", "bar", "baz"},
+			ipsetVersion:    ipvs.MinIPSetCheckVersion,
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    true,
+			expected:        proxyModeIPTables,
+		},
+		{ // flag says ipvs, required kernel modules are not installed, iptables version too old, fallback on userspace mode
+			flag:            "ipvs",
+			mods:            []string{"foo", "bar", "baz"},
+			ipsetVersion:    ipvs.MinIPSetCheckVersion,
+			iptablesVersion: "0.0.0",
+			kernelCompat:    true,
+			expected:        proxyModeUserspace,
+		},
+		{ // flag says ipvs, ipset version too low, iptables version too old, kernel not compatible, fallback on userspace mode
+			flag:            "ipvs",
+			mods:            []string{"ip_vs", "ip_vs_rr", "ip_vs_wrr", "ip_vs_sh", "nf_conntrack_ipv4"},
+			ipsetVersion:    "0.0",
+			iptablesVersion: iptables.MinCheckVersion,
+			kernelCompat:    false,
+			expected:        proxyModeUserspace,
+		},
+	}
+	for i, c := range cases {
+		versioner := &fakeIPTablesVersioner{c.iptablesVersion, c.iptablesError}
+		kcompater := &fakeKernelCompatTester{c.kernelCompat}
+		ipsetver := &fakeIPSetVersioner{c.ipsetVersion, c.ipsetError}
+		khandle := &fakeKernelHandler{c.mods}
+		r := getProxyMode(c.flag, versioner, khandle, ipsetver, kcompater)
+		if r != c.expected {
+			t.Errorf("Case[%d] Expected %q, got %q", i, c.expected, r)
+		}
+	}
+}
+
 // This test verifies that NewProxyServer does not crash when CleanupAndExit is true.
 func TestProxyServerWithCleanupAndExit(t *testing.T) {
 	// Each bind address below is a separate test case