admission/webhook: move webhook initializer into plugin

Kubernetes-commit: e19257f2ec87d8091defb7935bb3a161fbb229d0

pkg/admission/BUILD

@@ -80,6 +80,7 @@ filegroup(
         "//staging/src/k8s.io/apiserver/pkg/admission/plugin/namespace/lifecycle:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/config:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/errors:all-srcs",
+        "//staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/initializer:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/mutating:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/namespace:all-srcs",
         "//staging/src/k8s.io/apiserver/pkg/admission/plugin/webhook/request:all-srcs",

pkg/admission/plugin/webhook/initializer/BUILD

@@ -0,0 +1,37 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["initializer.go"],
+    importpath = "k8s.io/apiserver/pkg/admission/plugin/webhook/initializer",
+    visibility = ["//visibility:public"],
+    deps = [
+        "//vendor/k8s.io/apiserver/pkg/admission:go_default_library",
+        "//vendor/k8s.io/apiserver/pkg/admission/plugin/webhook/config:go_default_library",
+    ],
+)
+
+go_test(
+    name = "go_default_test",
+    srcs = ["initializer_test.go"],
+    importpath = "k8s.io/apiserver/pkg/admission/plugin/webhook/initializer",
+    library = ":go_default_library",
+    deps = [
+        "//vendor/k8s.io/apiserver/pkg/admission:go_default_library",
+        "//vendor/k8s.io/apiserver/pkg/admission/plugin/webhook/config:go_default_library",
+    ],
+)
+
+filegroup(
+    name = "package-srcs",
+    srcs = glob(["**"]),
+    tags = ["automanaged"],
+    visibility = ["//visibility:private"],
+)
+
+filegroup(
+    name = "all-srcs",
+    srcs = [":package-srcs"],
+    tags = ["automanaged"],
+    visibility = ["//visibility:public"],
+)

pkg/admission/plugin/webhook/initializer/initializer.go

@@ -0,0 +1,76 @@
+/*
+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 initializer
+
+import (
+	"net/url"
+
+	"k8s.io/apiserver/pkg/admission"
+	webhookconfig "k8s.io/apiserver/pkg/admission/plugin/webhook/config"
+)
+
+// WantsServiceResolver defines a fuction that accepts a ServiceResolver for
+// admission plugins that need to make calls to services.
+type WantsServiceResolver interface {
+	SetServiceResolver(webhookconfig.ServiceResolver)
+}
+
+// ServiceResolver knows how to convert a service reference into an actual
+// location.
+type ServiceResolver interface {
+	ResolveEndpoint(namespace, name string) (*url.URL, error)
+}
+
+// WantsAuthenticationInfoResolverWrapper defines a function that wraps the standard AuthenticationInfoResolver
+// to allow the apiserver to control what is returned as auth info
+type WantsAuthenticationInfoResolverWrapper interface {
+	SetAuthenticationInfoResolverWrapper(webhookconfig.AuthenticationInfoResolverWrapper)
+	admission.InitializationValidator
+}
+
+// PluginInitializer is used for initialization of the webhook admission plugin.
+type PluginInitializer struct {
+	serviceResolver                   webhookconfig.ServiceResolver
+	authenticationInfoResolverWrapper webhookconfig.AuthenticationInfoResolverWrapper
+}
+
+var _ admission.PluginInitializer = &PluginInitializer{}
+
+// NewPluginInitializer constructs new instance of PluginInitializer
+func NewPluginInitializer(
+	authenticationInfoResolverWrapper webhookconfig.AuthenticationInfoResolverWrapper,
+	serviceResolver webhookconfig.ServiceResolver,
+) *PluginInitializer {
+	return &PluginInitializer{
+		authenticationInfoResolverWrapper: authenticationInfoResolverWrapper,
+		serviceResolver:                   serviceResolver,
+	}
+}
+
+// Initialize checks the initialization interfaces implemented by each plugin
+// and provide the appropriate initialization data
+func (i *PluginInitializer) Initialize(plugin admission.Interface) {
+	if wants, ok := plugin.(WantsServiceResolver); ok {
+		wants.SetServiceResolver(i.serviceResolver)
+	}
+
+	if wants, ok := plugin.(WantsAuthenticationInfoResolverWrapper); ok {
+		if i.authenticationInfoResolverWrapper != nil {
+			wants.SetAuthenticationInfoResolverWrapper(i.authenticationInfoResolverWrapper)
+		}
+	}
+}

pkg/admission/plugin/webhook/initializer/initializer_test.go

@@ -0,0 +1,54 @@
+/*
+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 initializer
+
+import (
+	"net/url"
+	"testing"
+
+	"k8s.io/apiserver/pkg/admission"
+	"k8s.io/apiserver/pkg/admission/plugin/webhook/config"
+)
+
+type doNothingAdmission struct{}
+
+func (doNothingAdmission) Admit(a admission.Attributes) error { return nil }
+func (doNothingAdmission) Handles(o admission.Operation) bool { return false }
+func (doNothingAdmission) Validate() error                    { return nil }
+
+type fakeServiceResolver struct{}
+
+func (f *fakeServiceResolver) ResolveEndpoint(namespace, name string) (*url.URL, error) {
+	return nil, nil
+}
+
+type serviceWanter struct {
+	doNothingAdmission
+	got ServiceResolver
+}
+
+func (s *serviceWanter) SetServiceResolver(sr config.ServiceResolver) { s.got = sr }
+
+func TestWantsServiceResolver(t *testing.T) {
+	sw := &serviceWanter{}
+	fsr := &fakeServiceResolver{}
+	i := NewPluginInitializer(nil, fsr)
+	i.Initialize(sw)
+	if got, ok := sw.got.(*fakeServiceResolver); !ok || got != fsr {
+		t.Errorf("plumbing fail - %v %v#", ok, got)
+	}
+}