ipam: CloudAllocator does not require service or cluster cidr

The inner logic of the controller already omits these fields, do
the same in the command line flags validation, otherwise it forces
the user to set some parameters that will be not used if the ipam
controller is the CloudAllocator

Change-Id: Ib539ca4bdce3e4f45b6b96edc7b581674db77528

Author: aojea

cmd/cloud-controller-manager/nodeipamcontroller.go

@@ -70,59 +70,66 @@ func (nodeIpamController *nodeIPAMController) startNodeIpamControllerWrapper(ini
 func startNodeIpamController(ccmConfig *cloudcontrollerconfig.CompletedConfig, nodeIPAMConfig nodeipamconfig.NodeIPAMControllerConfiguration, ctx genericcontrollermanager.ControllerContext, cloud cloudprovider.Interface) (controller.Interface, bool, error) {
 	var serviceCIDR *net.IPNet
 	var secondaryServiceCIDR *net.IPNet
+	var clusterCIDRs []*net.IPNet
+	var nodeCIDRMaskSizes []int
 
 	// should we start nodeIPAM
 	if !ccmConfig.ComponentConfig.KubeCloudShared.AllocateNodeCIDRs {
 		return nil, false, fmt.Errorf("the AllocateNodeCIDRs is not enabled")
 	}
 
-	// failure: bad cidrs in config
-	clusterCIDRs, dualStack, err := processCIDRs(ccmConfig.ComponentConfig.KubeCloudShared.ClusterCIDR)
-	if err != nil {
-		return nil, false, err
-	}
-
-	// failure: more than one cidr but they are not configured as dual stack
-	if len(clusterCIDRs) > 1 && !dualStack {
-		return nil, false, fmt.Errorf("len of ClusterCIDRs==%v and they are not configured as dual stack (at least one from each IPFamily", len(clusterCIDRs))
-	}
+	// the CloudAllocator ipam does not need service or cluster cidrs since it obtains the data from the cloud directly
+	// for backward compatiblity reasons we don't fail if there are any of those values configured
+	if ipam.CIDRAllocatorType(ccmConfig.ComponentConfig.KubeCloudShared.CIDRAllocatorType) != ipam.CloudAllocatorType {
+		// failure: bad cidrs in config
+		cidrs, dualStack, err := processCIDRs(ccmConfig.ComponentConfig.KubeCloudShared.ClusterCIDR)
+		if err != nil {
+			return nil, false, err
+		}
+		clusterCIDRs = cidrs
 
-	// failure: more than cidrs is not allowed even with dual stack
-	if len(clusterCIDRs) > 2 {
-		return nil, false, fmt.Errorf("len of clusters is:%v > more than max allowed of 2", len(clusterCIDRs))
-	}
+		// failure: more than one cidr but they are not configured as dual stack
+		if len(clusterCIDRs) > 1 && !dualStack {
+			return nil, false, fmt.Errorf("len of ClusterCIDRs==%v and they are not configured as dual stack (at least one from each IPFamily", len(clusterCIDRs))
+		}
 
-	// service cidr processing
-	if len(strings.TrimSpace(nodeIPAMConfig.ServiceCIDR)) != 0 {
-		_, serviceCIDR, err = net.ParseCIDR(nodeIPAMConfig.ServiceCIDR)
-		if err != nil {
-			klog.Warningf("Unsuccessful parsing of service CIDR %v: %v", nodeIPAMConfig.ServiceCIDR, err)
+		// failure: more than cidrs is not allowed even with dual stack
+		if len(clusterCIDRs) > 2 {
+			return nil, false, fmt.Errorf("len of clusters is:%v > more than max allowed of 2", len(clusterCIDRs))
 		}
-	}
 
-	if len(strings.TrimSpace(nodeIPAMConfig.SecondaryServiceCIDR)) != 0 {
-		_, secondaryServiceCIDR, err = net.ParseCIDR(nodeIPAMConfig.SecondaryServiceCIDR)
-		if err != nil {
-			klog.Warningf("Unsuccessful parsing of service CIDR %v: %v", nodeIPAMConfig.SecondaryServiceCIDR, err)
+		// service cidr processing
+		if len(strings.TrimSpace(nodeIPAMConfig.ServiceCIDR)) != 0 {
+			_, serviceCIDR, err = net.ParseCIDR(nodeIPAMConfig.ServiceCIDR)
+			if err != nil {
+				klog.Warningf("Unsuccessful parsing of service CIDR %v: %v", nodeIPAMConfig.ServiceCIDR, err)
+			}
 		}
-	}
 
-	// the following checks are triggered if both serviceCIDR and secondaryServiceCIDR are provided
-	if serviceCIDR != nil && secondaryServiceCIDR != nil {
-		// should be dual stack (from different IPFamilies)
-		dualstackServiceCIDR, err := netutils.IsDualStackCIDRs([]*net.IPNet{serviceCIDR, secondaryServiceCIDR})
-		if err != nil {
-			return nil, false, fmt.Errorf("failed to perform dualstack check on serviceCIDR and secondaryServiceCIDR error:%v", err)
+		if len(strings.TrimSpace(nodeIPAMConfig.SecondaryServiceCIDR)) != 0 {
+			_, secondaryServiceCIDR, err = net.ParseCIDR(nodeIPAMConfig.SecondaryServiceCIDR)
+			if err != nil {
+				klog.Warningf("Unsuccessful parsing of service CIDR %v: %v", nodeIPAMConfig.SecondaryServiceCIDR, err)
+			}
 		}
-		if !dualstackServiceCIDR {
-			return nil, false, fmt.Errorf("serviceCIDR and secondaryServiceCIDR are not dualstack (from different IPfamiles)")
+
+		// the following checks are triggered if both serviceCIDR and secondaryServiceCIDR are provided
+		if serviceCIDR != nil && secondaryServiceCIDR != nil {
+			// should be dual stack (from different IPFamilies)
+			dualstackServiceCIDR, err := netutils.IsDualStackCIDRs([]*net.IPNet{serviceCIDR, secondaryServiceCIDR})
+			if err != nil {
+				return nil, false, fmt.Errorf("failed to perform dualstack check on serviceCIDR and secondaryServiceCIDR error:%v", err)
+			}
+			if !dualstackServiceCIDR {
+				return nil, false, fmt.Errorf("serviceCIDR and secondaryServiceCIDR are not dualstack (from different IPfamiles)")
+			}
 		}
-	}
 
-	// get list of node cidr mask sizes
-	nodeCIDRMaskSizes, err := setNodeCIDRMaskSizes(nodeIPAMConfig, clusterCIDRs)
-	if err != nil {
-		return nil, false, err
+		// get list of node cidr mask sizes
+		nodeCIDRMaskSizes, err = setNodeCIDRMaskSizes(nodeIPAMConfig, clusterCIDRs)
+		if err != nil {
+			return nil, false, err
+		}
 	}
 
 	kubeConfig := ccmConfig.Complete().Kubeconfig