-
Notifications
You must be signed in to change notification settings - Fork 0
/
main.go
229 lines (207 loc) · 6.86 KB
/
main.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
package webhook
import (
"crypto/tls"
"encoding/json"
"fmt"
"io/ioutil"
"net"
"net/http"
"os"
"github.com/spf13/cobra"
v1 "k8s.io/api/admission/v1"
"k8s.io/api/admission/v1beta1"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/klog/v2"
"github.com/grepplabs/spring-config-decryptor/pkg/decryptor"
"github.com/oklog/run"
)
const (
defaultEnvEncryptKey = "ENCRYPT_KEY"
)
var (
tlsCertFile string
tlsKeyFile string
listenPort int
healthzPort int
encryptKeyFile string
)
// CmdWebhook is used by agnhost Cobra.
var CmdWebhook = &cobra.Command{
Use: "webhook",
Short: "Kubernetes mutating webhook decrypting configmaps and secrets encrypted with Spring Cloud Config asymmetric key",
Args: cobra.MaximumNArgs(0),
Run: main,
}
func init() {
CmdWebhook.Flags().StringVar(&tlsCertFile, "tls-cert-file", "", "File containing the default x509 Certificate for HTTPS. (CA cert, if any, concatenated after server cert).")
CmdWebhook.Flags().StringVar(&tlsKeyFile, "tls-private-key-file", "", "File containing the default x509 private key matching --tls-cert-file.")
CmdWebhook.Flags().IntVar(&listenPort, "secure-port", 6443, "port number to listen on for secure TLS connections")
CmdWebhook.Flags().IntVar(&healthzPort, "healthz-port", 6081, "port number to listen on for insecure healthz connections")
CmdWebhook.Flags().StringVar(&encryptKeyFile, "encrypt-key-file", "", fmt.Sprintf("The file with RSA private key. If empty the key is read from environment variable %s ", defaultEnvEncryptKey))
}
// admitv1beta1Func handles a v1beta1 admission
type admitv1beta1Func func(v1beta1.AdmissionReview) *v1beta1.AdmissionResponse
// admitv1beta1Func handles a v1 admission
type admitv1Func func(v1.AdmissionReview) *v1.AdmissionResponse
// admitHandler is a handler, for both validators and mutators, that supports multiple admission review versions
type admitHandler struct {
v1beta1 admitv1beta1Func
v1 admitv1Func
}
func newDelegateToV1AdmitHandler(f admitv1Func) admitHandler {
return admitHandler{
v1beta1: delegateV1beta1AdmitToV1(f),
v1: f,
}
}
func delegateV1beta1AdmitToV1(f admitv1Func) admitv1beta1Func {
return func(review v1beta1.AdmissionReview) *v1beta1.AdmissionResponse {
in := v1.AdmissionReview{Request: convertAdmissionRequestToV1(review.Request)}
out := f(in)
return convertAdmissionResponseToV1beta1(out)
}
}
// serve handles the http portion of a request prior to handing to an admit function
func serve(w http.ResponseWriter, r *http.Request, admit admitHandler) {
var body []byte
if r.Body != nil {
if data, err := ioutil.ReadAll(r.Body); err == nil {
body = data
}
}
// verify the content type is accurate
contentType := r.Header.Get("Content-Type")
if contentType != "application/json" {
klog.Errorf("contentType=%s, expect application/json", contentType)
return
}
klog.V(5).Info(fmt.Sprintf("handling request: %s", body))
deserializer := codecs.UniversalDeserializer()
obj, gvk, err := deserializer.Decode(body, nil, nil)
if err != nil {
msg := fmt.Sprintf("Request could not be decoded: %v", err)
klog.Error(msg)
http.Error(w, msg, http.StatusBadRequest)
return
}
var responseObj runtime.Object
switch *gvk {
case v1beta1.SchemeGroupVersion.WithKind("AdmissionReview"):
requestedAdmissionReview, ok := obj.(*v1beta1.AdmissionReview)
if !ok {
klog.Errorf("Expected v1beta1.AdmissionReview but got: %T", obj)
return
}
responseAdmissionReview := &v1beta1.AdmissionReview{}
responseAdmissionReview.SetGroupVersionKind(*gvk)
responseAdmissionReview.Response = admit.v1beta1(*requestedAdmissionReview)
responseAdmissionReview.Response.UID = requestedAdmissionReview.Request.UID
responseObj = responseAdmissionReview
case v1.SchemeGroupVersion.WithKind("AdmissionReview"):
requestedAdmissionReview, ok := obj.(*v1.AdmissionReview)
if !ok {
klog.Errorf("Expected v1.AdmissionReview but got: %T", obj)
return
}
responseAdmissionReview := &v1.AdmissionReview{}
responseAdmissionReview.SetGroupVersionKind(*gvk)
responseAdmissionReview.Response = admit.v1(*requestedAdmissionReview)
responseAdmissionReview.Response.UID = requestedAdmissionReview.Request.UID
responseObj = responseAdmissionReview
default:
msg := fmt.Sprintf("Unsupported group version kind: %v", gvk)
klog.Error(msg)
http.Error(w, msg, http.StatusBadRequest)
return
}
respBytes, err := json.Marshal(responseObj)
if err != nil {
klog.Error(err)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
klog.V(5).Info(fmt.Sprintf("sending response: %s", respBytes))
w.Header().Set("Content-Type", "application/json")
if _, err := w.Write(respBytes); err != nil {
klog.Error(err)
}
}
func main(_ *cobra.Command, _ []string) {
var g run.Group
{
healthzAddr := fmt.Sprintf(":%d", healthzPort)
l, err := net.Listen("tcp", healthzAddr)
if err != nil {
klog.Error(err)
os.Exit(1)
}
g.Add(func() error {
mux := http.NewServeMux()
mux.HandleFunc("/healthz", func(w http.ResponseWriter, req *http.Request) { _, _ = w.Write([]byte("ok")) })
mux.HandleFunc("/livez", func(w http.ResponseWriter, req *http.Request) { _, _ = w.Write([]byte("ok")) })
klog.Info("listening for insecure healthz connections", "address", healthzAddr)
srv := &http.Server{
Handler: mux,
}
return srv.Serve(l)
}, func(error) {
_ = l.Close()
})
}
{
listenAddr := fmt.Sprintf(":%d", listenPort)
l, err := net.Listen("tcp", listenAddr)
if err != nil {
klog.Error(err)
os.Exit(1)
}
g.Add(func() error {
encryptKey, err := getEncryptKey()
if err != nil {
return err
}
configDecryptor, err := decryptor.NewDecryptor(encryptKey)
if err != nil {
return err
}
admissionReviewMutator := NewAdmissionReviewMutator(configDecryptor)
mux := http.NewServeMux()
mux.HandleFunc("/configmaps", func(w http.ResponseWriter, r *http.Request) {
serve(w, r, newDelegateToV1AdmitHandler(admissionReviewMutator.admitConfigMaps))
})
mux.HandleFunc("/secrets", func(w http.ResponseWriter, r *http.Request) {
serve(w, r, newDelegateToV1AdmitHandler(admissionReviewMutator.admitSecrets))
})
klog.Info("listening for secure connections", "address", listenAddr)
sCert, err := tls.LoadX509KeyPair(tlsCertFile, tlsKeyFile)
if err != nil {
return err
}
l = tls.NewListener(l, &tls.Config{
Certificates: []tls.Certificate{sCert},
})
srv := &http.Server{
Handler: mux,
}
return srv.Serve(l)
}, func(error) {
_ = l.Close()
})
}
err := g.Run()
if err != nil {
klog.Error(err)
os.Exit(1)
}
}
func getEncryptKey() ([]byte, error) {
if len(encryptKeyFile) != 0 {
return ioutil.ReadFile(encryptKeyFile)
} else {
value := os.Getenv(defaultEnvEncryptKey)
if value == "" {
return nil, fmt.Errorf("missing private key error, provide key in the env variable %s or use --encrypt-key-file flag", defaultEnvEncryptKey)
}
return []byte(value), nil
}
}