Delete default load balancer source range (0.0.0.0/0) to prevent redundant network security rules.

Author: nilo19

staging/src/k8s.io/legacy-cloud-providers/azure/azure_loadbalancer.go

@@ -102,6 +102,8 @@ const (
 	serviceTagKey = "service"
 	// clusterNameKey is the cluster name key applied for public IP tags.
 	clusterNameKey = "kubernetes-cluster-name"
+
+	defaultLoadBalancerSourceRanges = "0.0.0.0/0"
 )
 
 // GetLoadBalancer returns whether the specified load balancer and its components exist, and
@@ -1130,6 +1132,7 @@ func (az *Cloud) reconcileSecurityGroup(clusterName string, service *v1.Service,
 	if lbIP != nil {
 		destinationIPAddress = *lbIP
 	}
+
 	if destinationIPAddress == "" {
 		destinationIPAddress = "*"
 	}
@@ -1139,6 +1142,12 @@ func (az *Cloud) reconcileSecurityGroup(clusterName string, service *v1.Service,
 		return nil, err
 	}
 	serviceTags := getServiceTags(service)
+	if len(serviceTags) != 0 {
+		if _, ok := sourceRanges[defaultLoadBalancerSourceRanges]; ok {
+			delete(sourceRanges, defaultLoadBalancerSourceRanges)
+		}
+	}
+
 	var sourceAddressPrefixes []string
 	if (sourceRanges == nil || servicehelpers.IsAllowAll(sourceRanges)) && len(serviceTags) == 0 {
 		if !requiresInternalLoadBalancer(service) {

staging/src/k8s.io/legacy-cloud-providers/azure/azure_loadbalancer_test.go

@@ -1891,6 +1891,48 @@ func TestReconcileSecurityGroup(t *testing.T) {
 				},
 			},
 		},
+		{
+			desc:    "reconcileSecurityGroup shall not create unwanted security rules if there is service tags",
+			service: getTestService("test1", v1.ProtocolTCP, map[string]string{ServiceAnnotationAllowedServiceTag: "tag"}, true, 80),
+			wantLb:  true,
+			lbIP:    to.StringPtr("1.1.1.1"),
+			existingSgs: map[string]network.SecurityGroup{"nsg": {
+				Name: to.StringPtr("nsg"),
+				SecurityGroupPropertiesFormat: &network.SecurityGroupPropertiesFormat{
+					SecurityRules: &[]network.SecurityRule{
+						{
+							Name: to.StringPtr("atest1-toBeDeleted"),
+							SecurityRulePropertiesFormat: &network.SecurityRulePropertiesFormat{
+								SourceAddressPrefix:      to.StringPtr("prefix"),
+								SourcePortRange:          to.StringPtr("range"),
+								DestinationAddressPrefix: to.StringPtr("desPrefix"),
+								DestinationPortRange:     to.StringPtr("desRange"),
+							},
+						},
+					},
+				},
+			}},
+			expectedSg: &network.SecurityGroup{
+				Name: to.StringPtr("nsg"),
+				SecurityGroupPropertiesFormat: &network.SecurityGroupPropertiesFormat{
+					SecurityRules: &[]network.SecurityRule{
+						{
+							Name: to.StringPtr("atest1-TCP-80-tag"),
+							SecurityRulePropertiesFormat: &network.SecurityRulePropertiesFormat{
+								Protocol:                 network.SecurityRuleProtocol("Tcp"),
+								SourcePortRange:          to.StringPtr("*"),
+								DestinationPortRange:     to.StringPtr("80"),
+								SourceAddressPrefix:      to.StringPtr("tag"),
+								DestinationAddressPrefix: to.StringPtr("1.1.1.1"),
+								Access:                   network.SecurityRuleAccess("Allow"),
+								Priority:                 to.Int32Ptr(500),
+								Direction:                network.SecurityRuleDirection("Inbound"),
+							},
+						},
+					},
+				},
+			},
+		},
 	}
 
 	for i, test := range testCases {