Add glue for legacy interface for backward compatibility.

staging/src/k8s.io/client-go/discovery/BUILD

@@ -42,8 +42,7 @@ filegroup(
     name = "all-srcs",
     srcs = [
         ":package-srcs",
-        "//staging/src/k8s.io/client-go/discovery/cached/disk:all-srcs",
+        "//staging/src/k8s.io/client-go/discovery/cached:all-srcs",
-        "//staging/src/k8s.io/client-go/discovery/cached/memory:all-srcs",
         "//staging/src/k8s.io/client-go/discovery/fake:all-srcs",
     ],
     tags = ["automanaged"],

staging/src/k8s.io/client-go/discovery/cached/BUILD

@@ -0,0 +1,31 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["legacy.go"],
+    importmap = "k8s.io/kubernetes/vendor/k8s.io/client-go/discovery/cached",
+    importpath = "k8s.io/client-go/discovery/cached",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//staging/src/k8s.io/client-go/discovery:go_default_library",
+        "//staging/src/k8s.io/client-go/discovery/cached/memory:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [
+        ":package-srcs",
+        "//staging/src/k8s.io/client-go/discovery/cached/disk:all-srcs",
+        "//staging/src/k8s.io/client-go/discovery/cached/memory:all-srcs",
+    ],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

staging/src/k8s.io/client-go/discovery/cached/legacy.go

@@ -0,0 +1,30 @@
+/*
+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 memory
+
+import (
+	"k8s.io/client-go/discovery"
+	"k8s.io/client-go/discovery/cached/memory"
+)
+
+// NewMemCacheClient is DEPRECATED. Use memory.NewMemCacheClient directly.
+func NewMemCacheClient(delegate discovery.DiscoveryInterface) discovery.CachedDiscoveryInterface {
+	return memory.NewMemCacheClient(delegate)
+}
+
+// ErrCacheNotFound is DEPRECATED. Use memory.ErrCacheNotFound directly.
+var ErrCacheNotFound = memory.ErrCacheNotFound