-
Notifications
You must be signed in to change notification settings - Fork 403
/
authentication.go
172 lines (150 loc) · 6.05 KB
/
authentication.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
/*
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 filters
import (
"errors"
"net/http"
"strings"
"time"
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/runtime/schema"
"k8s.io/apiserver/pkg/authentication/authenticator"
"k8s.io/apiserver/pkg/endpoints/handlers/responsewriters"
genericapirequest "k8s.io/apiserver/pkg/endpoints/request"
"k8s.io/component-base/metrics"
"k8s.io/component-base/metrics/legacyregistry"
"k8s.io/klog"
)
/*
* By default, all the following metrics are defined as falling under
* ALPHA stability level https://github.com/kubernetes/enhancements/blob/master/keps/sig-instrumentation/20190404-kubernetes-control-plane-metrics-stability.md#stability-classes)
*
* Promoting the stability level of the metric is a responsibility of the component owner, since it
* involves explicitly acknowledging support for the metric across multiple releases, in accordance with
* the metric stability policy.
*/
const (
successLabel = "success"
failureLabel = "failure"
errorLabel = "error"
)
var (
authenticatedUserCounter = metrics.NewCounterVec(
&metrics.CounterOpts{
Name: "authenticated_user_requests",
Help: "Counter of authenticated requests broken out by username.",
StabilityLevel: metrics.ALPHA,
},
[]string{"username"},
)
authenticatedAttemptsCounter = metrics.NewCounterVec(
&metrics.CounterOpts{
Name: "authentication_attempts",
Help: "Counter of authenticated attempts.",
StabilityLevel: metrics.ALPHA,
},
[]string{"result"},
)
authenticationLatency = metrics.NewHistogramVec(
&metrics.HistogramOpts{
Name: "authentication_duration_seconds",
Help: "Authentication duration in seconds broken out by result.",
Buckets: metrics.ExponentialBuckets(0.001, 2, 15),
StabilityLevel: metrics.ALPHA,
},
[]string{"result"},
)
)
func init() {
legacyregistry.MustRegister(authenticatedUserCounter)
legacyregistry.MustRegister(authenticatedAttemptsCounter)
legacyregistry.MustRegister(authenticationLatency)
}
// WithAuthentication creates an http handler that tries to authenticate the given request as a user, and then
// stores any such user found onto the provided context for the request. If authentication fails or returns an error
// the failed handler is used. On success, "Authorization" header is removed from the request and handler
// is invoked to serve the request.
func WithAuthentication(handler http.Handler, auth authenticator.Request, failed http.Handler, apiAuds authenticator.Audiences) http.Handler {
if auth == nil {
klog.Warningf("Authentication is disabled")
return handler
}
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
authenticationStart := time.Now()
if len(apiAuds) > 0 {
req = req.WithContext(authenticator.WithAudiences(req.Context(), apiAuds))
}
resp, ok, err := auth.AuthenticateRequest(req)
if err != nil || !ok {
if err != nil {
klog.Errorf("Unable to authenticate the request due to an error: %v", err)
authenticatedAttemptsCounter.WithLabelValues(errorLabel).Inc()
authenticationLatency.WithLabelValues(errorLabel).Observe(time.Since(authenticationStart).Seconds())
} else if !ok {
authenticatedAttemptsCounter.WithLabelValues(failureLabel).Inc()
authenticationLatency.WithLabelValues(failureLabel).Observe(time.Since(authenticationStart).Seconds())
}
failed.ServeHTTP(w, req)
return
}
if len(apiAuds) > 0 && len(resp.Audiences) > 0 && len(authenticator.Audiences(apiAuds).Intersect(resp.Audiences)) == 0 {
klog.Errorf("Unable to match the audience: %v , accepted: %v", resp.Audiences, apiAuds)
failed.ServeHTTP(w, req)
return
}
// authorization header is not required anymore in case of a successful authentication.
req.Header.Del("Authorization")
req = req.WithContext(genericapirequest.WithUser(req.Context(), resp.User))
authenticatedUserCounter.WithLabelValues(compressUsername(resp.User.GetName())).Inc()
authenticatedAttemptsCounter.WithLabelValues(successLabel).Inc()
authenticationLatency.WithLabelValues(successLabel).Observe(time.Since(authenticationStart).Seconds())
handler.ServeHTTP(w, req)
})
}
func Unauthorized(s runtime.NegotiatedSerializer, supportsBasicAuth bool) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
if supportsBasicAuth {
w.Header().Set("WWW-Authenticate", `Basic realm="kubernetes-master"`)
}
ctx := req.Context()
requestInfo, found := genericapirequest.RequestInfoFrom(ctx)
if !found {
responsewriters.InternalError(w, req, errors.New("no RequestInfo found in the context"))
return
}
gv := schema.GroupVersion{Group: requestInfo.APIGroup, Version: requestInfo.APIVersion}
responsewriters.ErrorNegotiated(apierrors.NewUnauthorized("Unauthorized"), s, gv, w, req)
})
}
// compressUsername maps all possible usernames onto a small set of categories
// of usernames. This is done both to limit the cardinality of the
// authorized_user_requests metric, and to avoid pushing actual usernames in the
// metric.
func compressUsername(username string) string {
switch {
// Known internal identities.
case username == "admin" ||
username == "client" ||
username == "kube_proxy" ||
username == "kubelet" ||
username == "system:serviceaccount:kube-system:default":
return username
// Probably an email address.
case strings.Contains(username, "@"):
return "email_id"
// Anything else (custom service accounts, custom external identities, etc.)
default:
return "other"
}
}