/*
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 auth

import (
	"fmt"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

	storagev1beta1 "k8s.io/api/storage/v1beta1"
	"k8s.io/apimachinery/pkg/api/errors"
	"k8s.io/apimachinery/pkg/api/resource"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/types"
	"k8s.io/apimachinery/pkg/util/wait"
	"k8s.io/apiserver/pkg/authentication/request/bearertoken"
	"k8s.io/apiserver/pkg/authentication/token/tokenfile"
	"k8s.io/apiserver/pkg/authentication/user"
	utilfeature "k8s.io/apiserver/pkg/util/feature"
	utilfeaturetesting "k8s.io/apiserver/pkg/util/feature/testing"
	versionedinformers "k8s.io/client-go/informers"
	externalclientset "k8s.io/client-go/kubernetes"
	restclient "k8s.io/client-go/rest"
	"k8s.io/kubernetes/pkg/api/legacyscheme"
	api "k8s.io/kubernetes/pkg/apis/core"
	"k8s.io/kubernetes/pkg/apis/policy"
	"k8s.io/kubernetes/pkg/auth/nodeidentifier"
	clientset "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset"
	informers "k8s.io/kubernetes/pkg/client/informers/informers_generated/internalversion"
	"k8s.io/kubernetes/pkg/features"
	"k8s.io/kubernetes/pkg/kubeapiserver/authorizer"
	"k8s.io/kubernetes/plugin/pkg/admission/noderestriction"
	"k8s.io/kubernetes/test/integration/framework"
)

func TestNodeAuthorizer(t *testing.T) {
	// Start the server so we know the address
	h := &framework.MasterHolder{Initialized: make(chan struct{})}
	apiServer := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
		<-h.Initialized
		h.M.GenericAPIServer.Handler.ServeHTTP(w, req)
	}))

	const (
		// Define credentials
		tokenMaster      = "master-token"
		tokenNodeUnknown = "unknown-token"
		tokenNode1       = "node1-token"
		tokenNode2       = "node2-token"
	)

	authenticator := bearertoken.New(tokenfile.New(map[string]*user.DefaultInfo{
		tokenMaster:      {Name: "admin", Groups: []string{"system:masters"}},
		tokenNodeUnknown: {Name: "unknown", Groups: []string{"system:nodes"}},
		tokenNode1:       {Name: "system:node:node1", Groups: []string{"system:nodes"}},
		tokenNode2:       {Name: "system:node:node2", Groups: []string{"system:nodes"}},
	}))

	// Build client config, clientset, and informers
	clientConfig := &restclient.Config{Host: apiServer.URL, ContentConfig: restclient.ContentConfig{NegotiatedSerializer: legacyscheme.Codecs}}
	superuserClient, superuserClientExternal := clientsetForToken(tokenMaster, clientConfig)
	informerFactory := informers.NewSharedInformerFactory(superuserClient, time.Minute)
	versionedInformerFactory := versionedinformers.NewSharedInformerFactory(superuserClientExternal, time.Minute)

	// Enabled CSIPersistentVolume feature at startup so volumeattachments get watched
	defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.CSIPersistentVolume, true)()

	// Set up Node+RBAC authorizer
	authorizerConfig := &authorizer.AuthorizationConfig{
		AuthorizationModes:       []string{"Node", "RBAC"},
		InformerFactory:          informerFactory,
		VersionedInformerFactory: versionedInformerFactory,
	}
	nodeRBACAuthorizer, _, err := authorizerConfig.New()
	if err != nil {
		t.Fatal(err)
	}

	// Set up NodeRestriction admission
	nodeRestrictionAdmission := noderestriction.NewPlugin(nodeidentifier.NewDefaultNodeIdentifier())
	nodeRestrictionAdmission.SetInternalKubeClientSet(superuserClient)
	if err := nodeRestrictionAdmission.ValidateInitialization(); err != nil {
		t.Fatal(err)
	}

	// Start the server
	masterConfig := framework.NewIntegrationTestMasterConfig()
	masterConfig.GenericConfig.Authentication.Authenticator = authenticator
	masterConfig.GenericConfig.Authorization.Authorizer = nodeRBACAuthorizer
	masterConfig.GenericConfig.AdmissionControl = nodeRestrictionAdmission

	_, _, closeFn := framework.RunAMasterUsingServer(masterConfig, apiServer, h)
	defer closeFn()

	// Start the informers
	stopCh := make(chan struct{})
	defer close(stopCh)
	informerFactory.Start(stopCh)
	versionedInformerFactory.Start(stopCh)

	// Wait for a healthy server
	for {
		result := superuserClient.Core().RESTClient().Get().AbsPath("/healthz").Do()
		_, err := result.Raw()
		if err == nil {
			break
		}
		t.Log(err)
		time.Sleep(time.Second)
	}

	// Create objects
	if _, err := superuserClient.Core().Secrets("ns").Create(&api.Secret{ObjectMeta: metav1.ObjectMeta{Name: "mysecret"}}); err != nil {
		t.Fatal(err)
	}
	if _, err := superuserClient.Core().Secrets("ns").Create(&api.Secret{ObjectMeta: metav1.ObjectMeta{Name: "mypvsecret"}}); err != nil {
		t.Fatal(err)
	}
	if _, err := superuserClient.Core().ConfigMaps("ns").Create(&api.ConfigMap{ObjectMeta: metav1.ObjectMeta{Name: "myconfigmap"}}); err != nil {
		t.Fatal(err)
	}
	pvName := "mypv"
	if _, err := superuserClientExternal.StorageV1beta1().VolumeAttachments().Create(&storagev1beta1.VolumeAttachment{
		ObjectMeta: metav1.ObjectMeta{Name: "myattachment"},
		Spec: storagev1beta1.VolumeAttachmentSpec{
			Attacher: "foo",
			Source:   storagev1beta1.VolumeAttachmentSource{PersistentVolumeName: &pvName},
			NodeName: "node2",
		},
	}); err != nil {
		t.Fatal(err)
	}
	if _, err := superuserClient.Core().PersistentVolumeClaims("ns").Create(&api.PersistentVolumeClaim{
		ObjectMeta: metav1.ObjectMeta{Name: "mypvc"},
		Spec: api.PersistentVolumeClaimSpec{
			AccessModes: []api.PersistentVolumeAccessMode{api.ReadOnlyMany},
			Resources:   api.ResourceRequirements{Requests: api.ResourceList{api.ResourceStorage: resource.MustParse("1")}},
		},
	}); err != nil {
		t.Fatal(err)
	}

	if _, err := superuserClient.Core().PersistentVolumes().Create(&api.PersistentVolume{
		ObjectMeta: metav1.ObjectMeta{Name: "mypv"},
		Spec: api.PersistentVolumeSpec{
			AccessModes:            []api.PersistentVolumeAccessMode{api.ReadOnlyMany},
			Capacity:               api.ResourceList{api.ResourceStorage: resource.MustParse("1")},
			ClaimRef:               &api.ObjectReference{Namespace: "ns", Name: "mypvc"},
			PersistentVolumeSource: api.PersistentVolumeSource{AzureFile: &api.AzureFilePersistentVolumeSource{ShareName: "default", SecretName: "mypvsecret"}},
		},
	}); err != nil {
		t.Fatal(err)
	}

	getSecret := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().Secrets("ns").Get("mysecret", metav1.GetOptions{})
			return err
		}
	}
	getPVSecret := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().Secrets("ns").Get("mypvsecret", metav1.GetOptions{})
			return err
		}
	}
	getConfigMap := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().ConfigMaps("ns").Get("myconfigmap", metav1.GetOptions{})
			return err
		}
	}
	getPVC := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().PersistentVolumeClaims("ns").Get("mypvc", metav1.GetOptions{})
			return err
		}
	}
	getPV := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().PersistentVolumes().Get("mypv", metav1.GetOptions{})
			return err
		}
	}
	getVolumeAttachment := func(client externalclientset.Interface) func() error {
		return func() error {
			_, err := client.StorageV1beta1().VolumeAttachments().Get("myattachment", metav1.GetOptions{})
			return err
		}
	}

	createNode2NormalPod := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().Pods("ns").Create(&api.Pod{
				ObjectMeta: metav1.ObjectMeta{Name: "node2normalpod"},
				Spec: api.PodSpec{
					NodeName:   "node2",
					Containers: []api.Container{{Name: "image", Image: "busybox"}},
					Volumes: []api.Volume{
						{Name: "secret", VolumeSource: api.VolumeSource{Secret: &api.SecretVolumeSource{SecretName: "mysecret"}}},
						{Name: "cm", VolumeSource: api.VolumeSource{ConfigMap: &api.ConfigMapVolumeSource{LocalObjectReference: api.LocalObjectReference{Name: "myconfigmap"}}}},
						{Name: "pvc", VolumeSource: api.VolumeSource{PersistentVolumeClaim: &api.PersistentVolumeClaimVolumeSource{ClaimName: "mypvc"}}},
					},
				},
			})
			return err
		}
	}
	updateNode2NormalPodStatus := func(client clientset.Interface) func() error {
		return func() error {
			startTime := metav1.NewTime(time.Now())
			_, err := client.Core().Pods("ns").UpdateStatus(&api.Pod{
				ObjectMeta: metav1.ObjectMeta{Name: "node2normalpod"},
				Status:     api.PodStatus{StartTime: &startTime},
			})
			return err
		}
	}
	deleteNode2NormalPod := func(client clientset.Interface) func() error {
		return func() error {
			zero := int64(0)
			return client.Core().Pods("ns").Delete("node2normalpod", &metav1.DeleteOptions{GracePeriodSeconds: &zero})
		}
	}

	createNode2MirrorPod := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().Pods("ns").Create(&api.Pod{
				ObjectMeta: metav1.ObjectMeta{
					Name:        "node2mirrorpod",
					Annotations: map[string]string{api.MirrorPodAnnotationKey: "true"},
				},
				Spec: api.PodSpec{
					NodeName:   "node2",
					Containers: []api.Container{{Name: "image", Image: "busybox"}},
				},
			})
			return err
		}
	}
	deleteNode2MirrorPod := func(client clientset.Interface) func() error {
		return func() error {
			zero := int64(0)
			return client.Core().Pods("ns").Delete("node2mirrorpod", &metav1.DeleteOptions{GracePeriodSeconds: &zero})
		}
	}

	createNode2 := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().Nodes().Create(&api.Node{ObjectMeta: metav1.ObjectMeta{Name: "node2"}})
			return err
		}
	}
	updateNode2Status := func(client clientset.Interface) func() error {
		return func() error {
			_, err := client.Core().Nodes().UpdateStatus(&api.Node{
				ObjectMeta: metav1.ObjectMeta{Name: "node2"},
				Status:     api.NodeStatus{},
			})
			return err
		}
	}
	deleteNode2 := func(client clientset.Interface) func() error {
		return func() error {
			return client.Core().Nodes().Delete("node2", nil)
		}
	}
	createNode2NormalPodEviction := func(client clientset.Interface) func() error {
		return func() error {
			return client.Policy().Evictions("ns").Evict(&policy.Eviction{
				TypeMeta: metav1.TypeMeta{
					APIVersion: "policy/v1beta1",
					Kind:       "Eviction",
				},
				ObjectMeta: metav1.ObjectMeta{
					Name:      "node2normalpod",
					Namespace: "ns",
				},
			})
		}
	}
	createNode2MirrorPodEviction := func(client clientset.Interface) func() error {
		return func() error {
			return client.Policy().Evictions("ns").Evict(&policy.Eviction{
				TypeMeta: metav1.TypeMeta{
					APIVersion: "policy/v1beta1",
					Kind:       "Eviction",
				},
				ObjectMeta: metav1.ObjectMeta{
					Name:      "node2mirrorpod",
					Namespace: "ns",
				},
			})
		}
	}

	capacity := 50
	updatePVCCapacity := func(client clientset.Interface) func() error {
		return func() error {
			capacity++
			statusString := fmt.Sprintf("{\"status\": {\"capacity\": {\"storage\": \"%dG\"}}}", capacity)
			patchBytes := []byte(statusString)
			_, err := client.Core().PersistentVolumeClaims("ns").Patch("mypvc", types.StrategicMergePatchType, patchBytes, "status")
			return err
		}
	}

	updatePVCPhase := func(client clientset.Interface) func() error {
		return func() error {
			patchBytes := []byte(`{"status":{"phase": "Bound"}}`)
			_, err := client.Core().PersistentVolumeClaims("ns").Patch("mypvc", types.StrategicMergePatchType, patchBytes, "status")
			return err
		}
	}

	nodeanonClient, _ := clientsetForToken(tokenNodeUnknown, clientConfig)
	node1Client, node1ClientExternal := clientsetForToken(tokenNode1, clientConfig)
	node2Client, node2ClientExternal := clientsetForToken(tokenNode2, clientConfig)

	// all node requests from node1 and unknown node fail
	expectForbidden(t, getSecret(nodeanonClient))
	expectForbidden(t, getPVSecret(nodeanonClient))
	expectForbidden(t, getConfigMap(nodeanonClient))
	expectForbidden(t, getPVC(nodeanonClient))
	expectForbidden(t, getPV(nodeanonClient))
	expectForbidden(t, createNode2NormalPod(nodeanonClient))
	expectForbidden(t, createNode2MirrorPod(nodeanonClient))
	expectForbidden(t, deleteNode2NormalPod(nodeanonClient))
	expectForbidden(t, deleteNode2MirrorPod(nodeanonClient))
	expectForbidden(t, createNode2MirrorPodEviction(nodeanonClient))
	expectForbidden(t, createNode2(nodeanonClient))
	expectForbidden(t, updateNode2Status(nodeanonClient))
	expectForbidden(t, deleteNode2(nodeanonClient))

	expectForbidden(t, getSecret(node1Client))
	expectForbidden(t, getPVSecret(node1Client))
	expectForbidden(t, getConfigMap(node1Client))
	expectForbidden(t, getPVC(node1Client))
	expectForbidden(t, getPV(node1Client))
	expectForbidden(t, createNode2NormalPod(nodeanonClient))
	expectForbidden(t, createNode2MirrorPod(node1Client))
	expectNotFound(t, deleteNode2MirrorPod(node1Client))
	expectNotFound(t, createNode2MirrorPodEviction(node1Client))
	expectForbidden(t, createNode2(node1Client))
	expectForbidden(t, updateNode2Status(node1Client))
	expectForbidden(t, deleteNode2(node1Client))

	// related object requests from node2 fail
	expectForbidden(t, getSecret(node2Client))
	expectForbidden(t, getPVSecret(node2Client))
	expectForbidden(t, getConfigMap(node2Client))
	expectForbidden(t, getPVC(node2Client))
	expectForbidden(t, getPV(node2Client))

	expectForbidden(t, createNode2NormalPod(nodeanonClient))
	// mirror pod and self node lifecycle is allowed
	expectAllowed(t, createNode2MirrorPod(node2Client))
	expectAllowed(t, deleteNode2MirrorPod(node2Client))
	expectAllowed(t, createNode2MirrorPod(node2Client))
	expectAllowed(t, createNode2MirrorPodEviction(node2Client))
	expectAllowed(t, createNode2(node2Client))
	expectAllowed(t, updateNode2Status(node2Client))
	expectAllowed(t, deleteNode2(node2Client))

	// create a pod as an admin to add object references
	expectAllowed(t, createNode2NormalPod(superuserClient))

	// unidentifiable node and node1 are still forbidden
	expectForbidden(t, getSecret(nodeanonClient))
	expectForbidden(t, getPVSecret(nodeanonClient))
	expectForbidden(t, getConfigMap(nodeanonClient))
	expectForbidden(t, getPVC(nodeanonClient))
	expectForbidden(t, getPV(nodeanonClient))
	expectForbidden(t, createNode2NormalPod(nodeanonClient))
	expectForbidden(t, updateNode2NormalPodStatus(nodeanonClient))
	expectForbidden(t, deleteNode2NormalPod(nodeanonClient))
	expectForbidden(t, createNode2NormalPodEviction(nodeanonClient))
	expectForbidden(t, createNode2MirrorPod(nodeanonClient))
	expectForbidden(t, deleteNode2MirrorPod(nodeanonClient))
	expectForbidden(t, createNode2MirrorPodEviction(nodeanonClient))

	expectForbidden(t, getSecret(node1Client))
	expectForbidden(t, getPVSecret(node1Client))
	expectForbidden(t, getConfigMap(node1Client))
	expectForbidden(t, getPVC(node1Client))
	expectForbidden(t, getPV(node1Client))
	expectForbidden(t, createNode2NormalPod(node1Client))
	expectForbidden(t, updateNode2NormalPodStatus(node1Client))
	expectForbidden(t, deleteNode2NormalPod(node1Client))
	expectForbidden(t, createNode2NormalPodEviction(node1Client))
	expectForbidden(t, createNode2MirrorPod(node1Client))
	expectNotFound(t, deleteNode2MirrorPod(node1Client))
	expectNotFound(t, createNode2MirrorPodEviction(node1Client))

	// node2 can get referenced objects now
	expectAllowed(t, getSecret(node2Client))
	expectAllowed(t, getPVSecret(node2Client))
	expectAllowed(t, getConfigMap(node2Client))
	expectAllowed(t, getPVC(node2Client))
	expectAllowed(t, getPV(node2Client))

	expectForbidden(t, createNode2NormalPod(node2Client))
	expectAllowed(t, updateNode2NormalPodStatus(node2Client))
	expectAllowed(t, deleteNode2NormalPod(node2Client))
	expectAllowed(t, createNode2MirrorPod(node2Client))
	expectAllowed(t, deleteNode2MirrorPod(node2Client))
	// recreate as an admin to test eviction
	expectAllowed(t, createNode2NormalPod(superuserClient))
	expectAllowed(t, createNode2MirrorPod(superuserClient))
	expectAllowed(t, createNode2NormalPodEviction(node2Client))
	expectAllowed(t, createNode2MirrorPodEviction(node2Client))

	// re-create a pod as an admin to add object references
	expectAllowed(t, createNode2NormalPod(superuserClient))

	// ExpandPersistentVolumes feature disabled
	defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.ExpandPersistentVolumes, false)()
	expectForbidden(t, updatePVCCapacity(node1Client))
	expectForbidden(t, updatePVCCapacity(node2Client))

	// ExpandPersistentVolumes feature enabled
	defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.ExpandPersistentVolumes, true)()
	expectForbidden(t, updatePVCCapacity(node1Client))
	expectAllowed(t, updatePVCCapacity(node2Client))
	expectForbidden(t, updatePVCPhase(node2Client))

	// Disabled CSIPersistentVolume feature
	defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.CSIPersistentVolume, false)()
	expectForbidden(t, getVolumeAttachment(node1ClientExternal))
	expectForbidden(t, getVolumeAttachment(node2ClientExternal))
	// Enabled CSIPersistentVolume feature
	defer utilfeaturetesting.SetFeatureGateDuringTest(t, utilfeature.DefaultFeatureGate, features.CSIPersistentVolume, true)()
	expectForbidden(t, getVolumeAttachment(node1ClientExternal))
	expectAllowed(t, getVolumeAttachment(node2ClientExternal))
}

// expect executes a function a set number of times until it either returns the
// expected error or executes too many times. It returns if the retries timed
// out and the last error returned by the method.
func expect(t *testing.T, f func() error, wantErr func(error) bool) (timeout bool, lastErr error) {
	t.Helper()
	err := wait.PollImmediate(time.Second, 30*time.Second, func() (bool, error) {
		t.Helper()
		lastErr = f()
		if wantErr(lastErr) {
			return true, nil
		}
		t.Logf("unexpected response, will retry: %v", lastErr)
		return false, nil
	})
	return err == nil, lastErr
}

func expectForbidden(t *testing.T, f func() error) {
	t.Helper()
	if ok, err := expect(t, f, errors.IsForbidden); !ok {
		t.Errorf("Expected forbidden error, got %v", err)
	}
}

func expectNotFound(t *testing.T, f func() error) {
	t.Helper()
	if ok, err := expect(t, f, errors.IsNotFound); !ok {
		t.Errorf("Expected notfound error, got %v", err)
	}
}

func expectAllowed(t *testing.T, f func() error) {
	t.Helper()
	if ok, err := expect(t, f, func(e error) bool { return e == nil }); !ok {
		t.Errorf("Expected no error, got %v", err)
	}
}