add build tags to legacy provider code and make it possible to build kube-controller-manager without any legacyproviders or without particular legacy providers

pkg/controller/nodeipam/nolegacyprovider.go

@@ -0,0 +1,40 @@
+// +build nolegacyproviders
+
+/*
+Copyright 2019 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package nodeipam
+
+import (
+	"net"
+
+	coreinformers "k8s.io/client-go/informers/core/v1"
+	clientset "k8s.io/client-go/kubernetes"
+	cloudprovider "k8s.io/cloud-provider"
+	"k8s.io/klog"
+)
+
+func startLegacyIPAM(
+	ic *Controller,
+	nodeInformer coreinformers.NodeInformer,
+	cloud cloudprovider.Interface,
+	kubeClient clientset.Interface,
+	clusterCIDRs []*net.IPNet,
+	serviceCIDR *net.IPNet,
+	nodeCIDRMaskSize int,
+) {
+	klog.Fatal("Error trying to Init(): legacy cloud provider support disabled at build time")
+}