(ALPHA GCP FEATURE) Add IPAM controller

IPAM controller unifies handling of node pod CIDR range allocation.  It
is intended to supersede the logic that is currently in range_allocator
and cloud_cidr_allocator.

Note: for this change, the other allocators still exist and are the
default.

It supports two modes:
* CIDR range allocations done within the cluster that are then
propagated out to the cloud provider.
* Cloud provider managed IPAM that is then reflected into the cluster.

pkg/controller/node/ipam/test/BUILD

@@ -0,0 +1,21 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["utils.go"],
+    visibility = ["//visibility:public"],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

pkg/controller/node/ipam/test/utils.go

@@ -0,0 +1,31 @@
+/*
+Copyright 2017 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 test
+
+import (
+	"net"
+)
+
+// MustParseCIDR returns the CIDR range parsed from s or panics if the string
+// cannot be parsed.
+func MustParseCIDR(s string) *net.IPNet {
+	_, ret, err := net.ParseCIDR(s)
+	if err != nil {
+		panic(err)
+	}
+	return ret
+}