kube-proxy detect IP family based on nodeIP

We were detecting the IP family that kube-proxy should use
based on the bind address, however, this is not valid when
using an unspecified address, because on those cases
kube-proxy adopts the IP family of the address reported
in the Node API object.

The IP family will be determined by the nodeIP used by the proxier
The order of precedence is:
1. config.bindAddress if bindAddress is not 0.0.0.0 or ::
2. the primary IP from the Node object, if set
3. if no IP is found it defaults to 127.0.0.1 and IPv4

Signed-off-by: Antonio Ojea <antonio.ojea.garcia@gmail.com>

cmd/kube-proxy/app/server_test.go

@@ -36,36 +36,9 @@ import (
 
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	componentbaseconfig "k8s.io/component-base/config"
-	"k8s.io/component-base/configz"
 	kubeproxyconfig "k8s.io/kubernetes/pkg/proxy/apis/config"
 )
 
-// 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
-	bindAddresses := []string{
-		"0.0.0.0",
-		"::",
-	}
-	for _, addr := range bindAddresses {
-		options := NewOptions()
-
-		options.config = &kubeproxyconfig.KubeProxyConfiguration{
-			BindAddress: addr,
-		}
-		options.CleanupAndExit = true
-
-		proxyserver, err := NewProxyServer(options)
-
-		assert.Nil(t, err, "unexpected error in NewProxyServer, addr: %s", addr)
-		assert.NotNil(t, proxyserver, "nil proxy server obj, addr: %s", addr)
-		assert.NotNil(t, proxyserver.IptInterface, "nil iptables intf, addr: %s", addr)
-
-		// Clean up config for next test case
-		configz.Delete(kubeproxyconfig.GroupName)
-	}
-}
-
 func TestGetConntrackMax(t *testing.T) {
 	ncores := runtime.NumCPU()
 	testCases := []struct {