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move admission to genericapiserver

This commit is contained in:
deads2k 2017-01-17 16:42:13 -05:00
parent 0c810c8cb6
commit 0243c13f2a
8 changed files with 716 additions and 0 deletions
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10
pkg/admission/OWNERS Normal file
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approvers:
- davidopp
- derekwaynecarr
- erictune
- lavalamp
- liggitt
reviewers:
- deads2k
- ncdc
- smarterclayton

85
pkg/admission/attributes.go Normal file
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/*
Copyright 2014 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 admission
import (
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apiserver/pkg/authentication/user"
)
type attributesRecord struct {
kind schema.GroupVersionKind
namespace string
name string
resource schema.GroupVersionResource
subresource string
operation Operation
object runtime.Object
oldObject runtime.Object
userInfo user.Info
}
func NewAttributesRecord(object runtime.Object, oldObject runtime.Object, kind schema.GroupVersionKind, namespace, name string, resource schema.GroupVersionResource, subresource string, operation Operation, userInfo user.Info) Attributes {
return &attributesRecord{
kind: kind,
namespace: namespace,
name: name,
resource: resource,
subresource: subresource,
operation: operation,
object: object,
oldObject: oldObject,
userInfo: userInfo,
}
}
func (record *attributesRecord) GetKind() schema.GroupVersionKind {
return record.kind
}
func (record *attributesRecord) GetNamespace() string {
return record.namespace
}
func (record *attributesRecord) GetName() string {
return record.name
}
func (record *attributesRecord) GetResource() schema.GroupVersionResource {
return record.resource
}
func (record *attributesRecord) GetSubresource() string {
return record.subresource
}
func (record *attributesRecord) GetOperation() Operation {
return record.operation
}
func (record *attributesRecord) GetObject() runtime.Object {
return record.object
}
func (record *attributesRecord) GetOldObject() runtime.Object {
return record.oldObject
}
func (record *attributesRecord) GetUserInfo() user.Info {
return record.userInfo
}

49
pkg/admission/chain.go Normal file
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/*
Copyright 2014 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 admission
// chainAdmissionHandler is an instance of admission.Interface that performs admission control using a chain of admission handlers
type chainAdmissionHandler []Interface
// NewChainHandler creates a new chain handler from an array of handlers. Used for testing.
func NewChainHandler(handlers ...Interface) Interface {
return chainAdmissionHandler(handlers)
}
// Admit performs an admission control check using a chain of handlers, and returns immediately on first error
func (admissionHandler chainAdmissionHandler) Admit(a Attributes) error {
for _, handler := range admissionHandler {
if !handler.Handles(a.GetOperation()) {
continue
}
err := handler.Admit(a)
if err != nil {
return err
}
}
return nil
}
// Handles will return true if any of the handlers handles the given operation
func (admissionHandler chainAdmissionHandler) Handles(operation Operation) bool {
for _, handler := range admissionHandler {
if handler.Handles(operation) {
return true
}
}
return false
}

154
pkg/admission/chain_test.go Normal file
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/*
Copyright 2015 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 admission
import (
"fmt"
"testing"
"k8s.io/apimachinery/pkg/runtime/schema"
)
type FakeHandler struct {
*Handler
name string
admit bool
admitCalled bool
}
func (h *FakeHandler) Admit(a Attributes) (err error) {
h.admitCalled = true
if h.admit {
return nil
}
return fmt.Errorf("Don't admit")
}
func makeHandler(name string, admit bool, ops ...Operation) Interface {
return &FakeHandler{
name: name,
admit: admit,
Handler: NewHandler(ops...),
}
}
func TestAdmit(t *testing.T) {
tests := []struct {
name string
operation Operation
chain chainAdmissionHandler
accept bool
calls map[string]bool
}{
{
name: "all accept",
operation: Create,
chain: []Interface{
makeHandler("a", true, Update, Delete, Create),
makeHandler("b", true, Delete, Create),
makeHandler("c", true, Create),
},
calls: map[string]bool{"a": true, "b": true, "c": true},
accept: true,
},
{
name: "ignore handler",
operation: Create,
chain: []Interface{
makeHandler("a", true, Update, Delete, Create),
makeHandler("b", false, Delete),
makeHandler("c", true, Create),
},
calls: map[string]bool{"a": true, "c": true},
accept: true,
},
{
name: "ignore all",
operation: Connect,
chain: []Interface{
makeHandler("a", true, Update, Delete, Create),
makeHandler("b", false, Delete),
makeHandler("c", true, Create),
},
calls: map[string]bool{},
accept: true,
},
{
name: "reject one",
operation: Delete,
chain: []Interface{
makeHandler("a", true, Update, Delete, Create),
makeHandler("b", false, Delete),
makeHandler("c", true, Create),
},
calls: map[string]bool{"a": true, "b": true},
accept: false,
},
}
for _, test := range tests {
err := test.chain.Admit(NewAttributesRecord(nil, nil, schema.GroupVersionKind{}, "", "", schema.GroupVersionResource{}, "", test.operation, nil))
accepted := (err == nil)
if accepted != test.accept {
t.Errorf("%s: unexpected result of admit call: %v\n", test.name, accepted)
}
for _, h := range test.chain {
fake := h.(*FakeHandler)
_, shouldBeCalled := test.calls[fake.name]
if shouldBeCalled != fake.admitCalled {
t.Errorf("%s: handler %s not called as expected: %v", test.name, fake.name, fake.admitCalled)
continue
}
}
}
}
func TestHandles(t *testing.T) {
chain := chainAdmissionHandler{
makeHandler("a", true, Update, Delete, Create),
makeHandler("b", true, Delete, Create),
makeHandler("c", true, Create),
}
tests := []struct {
name string
operation Operation
chain chainAdmissionHandler
expected bool
}{
{
name: "all handle",
operation: Create,
expected: true,
},
{
name: "none handle",
operation: Connect,
expected: false,
},
{
name: "some handle",
operation: Delete,
expected: true,
},
}
for _, test := range tests {
handles := chain.Handles(test.operation)
if handles != test.expected {
t.Errorf("Unexpected handles result. Expected: %v. Actual: %v", test.expected, handles)
}
}
}

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pkg/admission/errors.go Normal file
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/*
Copyright 2015 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 admission
import (
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/api/meta"
"k8s.io/apimachinery/pkg/runtime/schema"
utilerrors "k8s.io/apimachinery/pkg/util/errors"
)
func extractResourceName(a Attributes) (name string, resource schema.GroupResource, err error) {
name = "Unknown"
resource = a.GetResource().GroupResource()
obj := a.GetObject()
if obj != nil {
accessor, err := meta.Accessor(obj)
if err != nil {
return "", schema.GroupResource{}, err
}
// this is necessary because name object name generation has not occurred yet
if len(accessor.GetName()) > 0 {
name = accessor.GetName()
} else if len(accessor.GetGenerateName()) > 0 {
name = accessor.GetGenerateName()
}
}
return name, resource, nil
}
// NewForbidden is a utility function to return a well-formatted admission control error response
func NewForbidden(a Attributes, internalError error) error {
// do not double wrap an error of same type
if apierrors.IsForbidden(internalError) {
return internalError
}
name, resource, err := extractResourceName(a)
if err != nil {
return apierrors.NewInternalError(utilerrors.NewAggregate([]error{internalError, err}))
}
return apierrors.NewForbidden(resource, name, internalError)
}
// NewNotFound is a utility function to return a well-formatted admission control error response
func NewNotFound(a Attributes) error {
name, resource, err := extractResourceName(a)
if err != nil {
return apierrors.NewInternalError(err)
}
return apierrors.NewNotFound(resource, name)
}

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/*
Copyright 2015 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 admission
import (
"time"
"k8s.io/apimachinery/pkg/util/sets"
)
const (
// timeToWaitForReady is the amount of time to wait to let an admission controller to be ready to satisfy a request.
// this is useful when admission controllers need to warm their caches before letting requests through.
timeToWaitForReady = 10 * time.Second
)
// ReadyFunc is a function that returns true if the admission controller is ready to handle requests.
type ReadyFunc func() bool
// Handler is a base for admission control handlers that
// support a predefined set of operations
type Handler struct {
operations sets.String
readyFunc ReadyFunc
}
// Handles returns true for methods that this handler supports
func (h *Handler) Handles(operation Operation) bool {
return h.operations.Has(string(operation))
}
// NewHandler creates a new base handler that handles the passed
// in operations
func NewHandler(ops ...Operation) *Handler {
operations := sets.NewString()
for _, op := range ops {
operations.Insert(string(op))
}
return &Handler{
operations: operations,
}
}
// SetReadyFunc allows late registration of a ReadyFunc to know if the handler is ready to process requests.
func (h *Handler) SetReadyFunc(readyFunc ReadyFunc) {
h.readyFunc = readyFunc
}
// WaitForReady will wait for the readyFunc (if registered) to return ready, and in case of timeout, will return false.
func (h *Handler) WaitForReady() bool {
// there is no ready func configured, so we return immediately
if h.readyFunc == nil {
return true
}
return h.waitForReadyInternal(time.After(timeToWaitForReady))
}
func (h *Handler) waitForReadyInternal(timeout <-chan time.Time) bool {
// there is no configured ready func, so return immediately
if h.readyFunc == nil {
return true
}
for !h.readyFunc() {
select {
case <-time.After(100 * time.Millisecond):
case <-timeout:
return h.readyFunc()
}
}
return true
}

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/*
Copyright 2014 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 admission
import (
"io"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apiserver/pkg/authentication/user"
)
// Attributes is an interface used by AdmissionController to get information about a request
// that is used to make an admission decision.
type Attributes interface {
// GetName returns the name of the object as presented in the request. On a CREATE operation, the client
// may omit name and rely on the server to generate the name. If that is the case, this method will return
// the empty string
GetName() string
// GetNamespace is the namespace associated with the request (if any)
GetNamespace() string
// GetResource is the name of the resource being requested. This is not the kind. For example: pods
GetResource() schema.GroupVersionResource
// GetSubresource is the name of the subresource being requested. This is a different resource, scoped to the parent resource, but it may have a different kind.
// For instance, /pods has the resource "pods" and the kind "Pod", while /pods/foo/status has the resource "pods", the sub resource "status", and the kind "Pod"
// (because status operates on pods). The binding resource for a pod though may be /pods/foo/binding, which has resource "pods", subresource "binding", and kind "Binding".
GetSubresource() string
// GetOperation is the operation being performed
GetOperation() Operation
// GetObject is the object from the incoming request prior to default values being applied
GetObject() runtime.Object
// GetOldObject is the existing object. Only populated for UPDATE requests.
GetOldObject() runtime.Object
// GetKind is the type of object being manipulated. For example: Pod
GetKind() schema.GroupVersionKind
// GetUserInfo is information about the requesting user
GetUserInfo() user.Info
}
// Interface is an abstract, pluggable interface for Admission Control decisions.
type Interface interface {
// Admit makes an admission decision based on the request attributes
Admit(a Attributes) (err error)
// Handles returns true if this admission controller can handle the given operation
// where operation can be one of CREATE, UPDATE, DELETE, or CONNECT
Handles(operation Operation) bool
}
// Operation is the type of resource operation being checked for admission control
type Operation string
// Operation constants
const (
Create Operation = "CREATE"
Update Operation = "UPDATE"
Delete Operation = "DELETE"
Connect Operation = "CONNECT"
)
// PluginInitializer is used for initialization of shareable resources between admission plugins.
// After initialization the resources have to be set separately
type PluginInitializer interface {
Initialize(plugin Interface)
}
// Validator holds Validate functions, which are responsible for validation of initialized shared resources
// and should be implemented on admission plugins
type Validator interface {
Validate() error
}
// ConfigProvider provides a way to get configuration for an admission plugin based on its name
type ConfigProvider interface {
ConfigFor(pluginName string) (io.Reader, error)
}

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/*
Copyright 2014 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 admission
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"reflect"
"sort"
"sync"
"github.com/golang/glog"
)
// Factory is a function that returns an Interface for admission decisions.
// The config parameter provides an io.Reader handler to the factory in
// order to load specific configurations. If no configuration is provided
// the parameter is nil.
type Factory func(config io.Reader) (Interface, error)
// All registered admission options.
var (
pluginsMutex sync.Mutex
plugins = make(map[string]Factory)
// PluginEnabledFn checks whether a plugin is enabled. By default, if you ask about it, it's enabled.
PluginEnabledFn = func(name string, config io.Reader) bool {
return true
}
)
// PluginEnabledFunc is a function type that can provide an external check on whether an admission plugin may be enabled
type PluginEnabledFunc func(name string, config io.Reader) bool
// GetPlugins enumerates the names of all registered plugins.
func GetPlugins() []string {
pluginsMutex.Lock()
defer pluginsMutex.Unlock()
keys := []string{}
for k := range plugins {
keys = append(keys, k)
}
sort.Strings(keys)
return keys
}
// RegisterPlugin registers a plugin Factory by name. This
// is expected to happen during app startup.
func RegisterPlugin(name string, plugin Factory) {
pluginsMutex.Lock()
defer pluginsMutex.Unlock()
_, found := plugins[name]
if found {
glog.Fatalf("Admission plugin %q was registered twice", name)
}
glog.V(1).Infof("Registered admission plugin %q", name)
plugins[name] = plugin
}
// getPlugin creates an instance of the named plugin. It returns `false` if the
// the name is not known. The error is returned only when the named provider was
// known but failed to initialize. The config parameter specifies the io.Reader
// handler of the configuration file for the cloud provider, or nil for no configuration.
func getPlugin(name string, config io.Reader) (Interface, bool, error) {
pluginsMutex.Lock()
defer pluginsMutex.Unlock()
f, found := plugins[name]
if !found {
return nil, false, nil
}
config1, config2, err := splitStream(config)
if err != nil {
return nil, true, err
}
if !PluginEnabledFn(name, config1) {
return nil, true, nil
}
ret, err := f(config2)
return ret, true, err
}
// splitStream reads the stream bytes and constructs two copies of it.
func splitStream(config io.Reader) (io.Reader, io.Reader, error) {
if config == nil || reflect.ValueOf(config).IsNil() {
return nil, nil, nil
}
configBytes, err := ioutil.ReadAll(config)
if err != nil {
return nil, nil, err
}
return bytes.NewBuffer(configBytes), bytes.NewBuffer(configBytes), nil
}
// NewFromPlugins returns an admission.Interface that will enforce admission control decisions of all
// the given plugins.
func NewFromPlugins(pluginNames []string, configProvider ConfigProvider, pluginInitializer PluginInitializer) (Interface, error) {
plugins := []Interface{}
for _, pluginName := range pluginNames {
pluginConfig, err := configProvider.ConfigFor(pluginName)
if err != nil {
return nil, err
}
plugin, err := InitPlugin(pluginName, pluginConfig, pluginInitializer)
if err != nil {
return nil, err
}
if plugin != nil {
plugins = append(plugins, plugin)
}
}
return chainAdmissionHandler(plugins), nil
}
// InitPlugin creates an instance of the named interface.
func InitPlugin(name string, config io.Reader, pluginInitializer PluginInitializer) (Interface, error) {
if name == "" {
glog.Info("No admission plugin specified.")
return nil, nil
}
plugin, found, err := getPlugin(name, config)
if err != nil {
return nil, fmt.Errorf("Couldn't init admission plugin %q: %v", name, err)
}
if !found {
return nil, fmt.Errorf("Unknown admission plugin: %s", name)
}
pluginInitializer.Initialize(plugin)
// ensure that plugins have been properly initialized
if err := Validate(plugin); err != nil {
return nil, err
}
return plugin, nil
}
// Validate will call the Validate function in each plugin if they implement
// the Validator interface.
func Validate(plugin Interface) error {
if validater, ok := plugin.(Validator); ok {
err := validater.Validate()
if err != nil {
return err
}
}
return nil
}
type PluginInitializers []PluginInitializer
func (pp PluginInitializers) Initialize(plugin Interface) {
for _, p := range pp {
p.Initialize(plugin)
}
}