1/*
2Copyright 2017 The Kubernetes Authors.
3
4Licensed under the Apache License, Version 2.0 (the "License");
5you may not use this file except in compliance with the License.
6You may obtain a copy of the License at
7
8    http://www.apache.org/licenses/LICENSE-2.0
9
10Unless required by applicable law or agreed to in writing, software
11distributed under the License is distributed on an "AS IS" BASIS,
12WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13See the License for the specific language governing permissions and
14limitations under the License.
15*/
16
17package webhook
18
19import (
20	stdjson "encoding/json"
21	"fmt"
22	"io"
23	"io/ioutil"
24	"net/http"
25	"net/http/httptest"
26	"os"
27	"reflect"
28	"testing"
29	"time"
30
31	"github.com/stretchr/testify/assert"
32	"github.com/stretchr/testify/require"
33
34	"k8s.io/apimachinery/pkg/runtime"
35	"k8s.io/apimachinery/pkg/runtime/schema"
36	"k8s.io/apimachinery/pkg/runtime/serializer/json"
37	"k8s.io/apimachinery/pkg/util/wait"
38	auditinternal "k8s.io/apiserver/pkg/apis/audit"
39	auditv1 "k8s.io/apiserver/pkg/apis/audit/v1"
40	auditv1beta1 "k8s.io/apiserver/pkg/apis/audit/v1beta1"
41	"k8s.io/apiserver/pkg/audit"
42	"k8s.io/client-go/tools/clientcmd/api/v1"
43)
44
45// newWebhookHandler returns a handler which receives webhook events and decodes the
46// request body. The caller passes a callback which is called on each webhook POST.
47// The object passed to cb is of the same type as list.
48func newWebhookHandler(t *testing.T, list runtime.Object, cb func(events runtime.Object)) http.Handler {
49	s := json.NewSerializer(json.DefaultMetaFactory, audit.Scheme, audit.Scheme, false)
50	return &testWebhookHandler{
51		t:          t,
52		list:       list,
53		onEvents:   cb,
54		serializer: s,
55	}
56}
57
58type testWebhookHandler struct {
59	t *testing.T
60
61	list     runtime.Object
62	onEvents func(events runtime.Object)
63
64	serializer runtime.Serializer
65}
66
67func (t *testWebhookHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
68	err := func() error {
69		body, err := ioutil.ReadAll(r.Body)
70		if err != nil {
71			return fmt.Errorf("read webhook request body: %v", err)
72		}
73
74		obj, _, err := t.serializer.Decode(body, nil, t.list.DeepCopyObject())
75		if err != nil {
76			return fmt.Errorf("decode request body: %v", err)
77		}
78		if reflect.TypeOf(obj).Elem() != reflect.TypeOf(t.list).Elem() {
79			return fmt.Errorf("expected %T, got %T", t.list, obj)
80		}
81		t.onEvents(obj)
82		return nil
83	}()
84
85	if err == nil {
86		io.WriteString(w, "{}")
87		return
88	}
89	// In a goroutine, can't call Fatal.
90	assert.NoError(t.t, err, "failed to read request body")
91	http.Error(w, err.Error(), http.StatusInternalServerError)
92}
93
94func newWebhook(t *testing.T, endpoint string, groupVersion schema.GroupVersion) *backend {
95	config := v1.Config{
96		Clusters: []v1.NamedCluster{
97			{Cluster: v1.Cluster{Server: endpoint, InsecureSkipTLSVerify: true}},
98		},
99	}
100	f, err := ioutil.TempFile("", "k8s_audit_webhook_test_")
101	require.NoError(t, err, "creating temp file")
102
103	defer func() {
104		f.Close()
105		os.Remove(f.Name())
106	}()
107
108	// NOTE(ericchiang): Do we need to use a proper serializer?
109	require.NoError(t, stdjson.NewEncoder(f).Encode(config), "writing kubeconfig")
110
111	retryBackoff := wait.Backoff{
112		Duration: 500 * time.Millisecond,
113		Factor:   1.5,
114		Jitter:   0.2,
115		Steps:    5,
116	}
117	b, err := NewBackend(f.Name(), groupVersion, retryBackoff, nil)
118	require.NoError(t, err, "initializing backend")
119
120	return b.(*backend)
121}
122
123func TestWebhook(t *testing.T) {
124	versions := []schema.GroupVersion{auditv1.SchemeGroupVersion, auditv1beta1.SchemeGroupVersion}
125	for _, version := range versions {
126		gotEvents := false
127
128		s := httptest.NewServer(newWebhookHandler(t, &auditv1.EventList{}, func(events runtime.Object) {
129			gotEvents = true
130		}))
131		defer s.Close()
132
133		backend := newWebhook(t, s.URL, auditv1.SchemeGroupVersion)
134
135		// Ensure this doesn't return a serialization error.
136		event := &auditinternal.Event{}
137		require.NoError(t, backend.processEvents(event), fmt.Sprintf("failed to send events, apiVersion: %s", version))
138		require.True(t, gotEvents, fmt.Sprintf("no events received, apiVersion: %s", version))
139	}
140}
141