forked from kubernetes/kubernetes
-
Notifications
You must be signed in to change notification settings - Fork 0
/
dispatcher.go
123 lines (106 loc) · 4.19 KB
/
dispatcher.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
/*
Copyright 2018 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 mutating delegates admission checks to dynamically configured
// mutating webhooks.
package mutating
import (
"context"
"fmt"
"time"
jsonpatch "github.com/evanphx/json-patch"
"github.com/golang/glog"
admissionv1beta1 "k8s.io/api/admission/v1beta1"
"k8s.io/api/admissionregistration/v1beta1"
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/runtime"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
admissionmetrics "k8s.io/apiserver/pkg/admission/metrics"
"k8s.io/apiserver/pkg/admission/plugin/webhook/config"
webhookerrors "k8s.io/apiserver/pkg/admission/plugin/webhook/errors"
"k8s.io/apiserver/pkg/admission/plugin/webhook/generic"
"k8s.io/apiserver/pkg/admission/plugin/webhook/request"
)
type mutatingDispatcher struct {
cm *config.ClientManager
plugin *Plugin
}
func newMutatingDispatcher(p *Plugin) func(cm *config.ClientManager) generic.Dispatcher {
return func(cm *config.ClientManager) generic.Dispatcher {
return &mutatingDispatcher{cm, p}
}
}
var _ generic.Dispatcher = &mutatingDispatcher{}
func (a *mutatingDispatcher) Dispatch(ctx context.Context, attr *generic.VersionedAttributes, relevantHooks []*v1beta1.Webhook) error {
for _, hook := range relevantHooks {
t := time.Now()
err := a.callAttrMutatingHook(ctx, hook, attr)
admissionmetrics.Metrics.ObserveWebhook(time.Since(t), err != nil, attr.Attributes, "admit", hook.Name)
if err == nil {
continue
}
ignoreClientCallFailures := hook.FailurePolicy != nil && *hook.FailurePolicy == v1beta1.Ignore
if callErr, ok := err.(*webhookerrors.ErrCallingWebhook); ok {
if ignoreClientCallFailures {
glog.Warningf("Failed calling webhook, failing open %v: %v", hook.Name, callErr)
utilruntime.HandleError(callErr)
continue
}
glog.Warningf("Failed calling webhook, failing closed %v: %v", hook.Name, err)
}
return apierrors.NewInternalError(err)
}
// convert attr.VersionedObject to the internal version in the underlying admission.Attributes
return a.plugin.scheme.Convert(attr.VersionedObject, attr.Attributes.GetObject(), nil)
}
// note that callAttrMutatingHook updates attr
func (a *mutatingDispatcher) callAttrMutatingHook(ctx context.Context, h *v1beta1.Webhook, attr *generic.VersionedAttributes) error {
// Make the webhook request
request := request.CreateAdmissionReview(attr)
client, err := a.cm.HookClient(h)
if err != nil {
return &webhookerrors.ErrCallingWebhook{WebhookName: h.Name, Reason: err}
}
response := &admissionv1beta1.AdmissionReview{}
if err := client.Post().Context(ctx).Body(&request).Do().Into(response); err != nil {
return &webhookerrors.ErrCallingWebhook{WebhookName: h.Name, Reason: err}
}
if response.Response == nil {
return &webhookerrors.ErrCallingWebhook{WebhookName: h.Name, Reason: fmt.Errorf("Webhook response was absent")}
}
if !response.Response.Allowed {
return webhookerrors.ToStatusErr(h.Name, response.Response.Result)
}
patchJS := response.Response.Patch
if len(patchJS) == 0 {
return nil
}
patchObj, err := jsonpatch.DecodePatch(patchJS)
if err != nil {
return apierrors.NewInternalError(err)
}
objJS, err := runtime.Encode(a.plugin.jsonSerializer, attr.VersionedObject)
if err != nil {
return apierrors.NewInternalError(err)
}
patchedJS, err := patchObj.Apply(objJS)
if err != nil {
return apierrors.NewInternalError(err)
}
// TODO: if we have multiple mutating webhooks, we can remember the json
// instead of encoding and decoding for each one.
if _, _, err := a.plugin.jsonSerializer.Decode(patchedJS, nil, attr.VersionedObject); err != nil {
return apierrors.NewInternalError(err)
}
a.plugin.scheme.Default(attr.VersionedObject)
return nil
}