1/* 2Copyright 2018 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 options 18 19import ( 20 "fmt" 21 "strings" 22 23 "github.com/spf13/pflag" 24 25 "k8s.io/apimachinery/pkg/util/sets" 26 "k8s.io/apiserver/pkg/admission" 27 "k8s.io/apiserver/pkg/server" 28 genericoptions "k8s.io/apiserver/pkg/server/options" 29 "k8s.io/client-go/informers" 30 "k8s.io/client-go/rest" 31 "k8s.io/component-base/featuregate" 32) 33 34// AdmissionOptions holds the admission options. 35// It is a wrap of generic AdmissionOptions. 36type AdmissionOptions struct { 37 // GenericAdmission holds the generic admission options. 38 GenericAdmission *genericoptions.AdmissionOptions 39 // DEPRECATED flag, should use EnabledAdmissionPlugins and DisabledAdmissionPlugins. 40 // They are mutually exclusive, specify both will lead to an error. 41 PluginNames []string 42} 43 44// NewAdmissionOptions creates a new instance of AdmissionOptions 45// Note: 46// In addition it calls RegisterAllAdmissionPlugins to register 47// all kube-apiserver admission plugins. 48// 49// Provides the list of RecommendedPluginOrder that holds sane values 50// that can be used by servers that don't care about admission chain. 51// Servers that do care can overwrite/append that field after creation. 52func NewAdmissionOptions() *AdmissionOptions { 53 options := genericoptions.NewAdmissionOptions() 54 // register all admission plugins 55 RegisterAllAdmissionPlugins(options.Plugins) 56 // set RecommendedPluginOrder 57 options.RecommendedPluginOrder = AllOrderedPlugins 58 // set DefaultOffPlugins 59 options.DefaultOffPlugins = DefaultOffAdmissionPlugins() 60 61 return &AdmissionOptions{ 62 GenericAdmission: options, 63 } 64} 65 66// AddFlags adds flags related to admission for kube-apiserver to the specified FlagSet 67func (a *AdmissionOptions) AddFlags(fs *pflag.FlagSet) { 68 fs.StringSliceVar(&a.PluginNames, "admission-control", a.PluginNames, ""+ 69 "Admission is divided into two phases. "+ 70 "In the first phase, only mutating admission plugins run. "+ 71 "In the second phase, only validating admission plugins run. "+ 72 "The names in the below list may represent a validating plugin, a mutating plugin, or both. "+ 73 "The order of plugins in which they are passed to this flag does not matter. "+ 74 "Comma-delimited list of: "+strings.Join(a.GenericAdmission.Plugins.Registered(), ", ")+".") 75 fs.MarkDeprecated("admission-control", "Use --enable-admission-plugins or --disable-admission-plugins instead. Will be removed in a future version.") 76 fs.Lookup("admission-control").Hidden = false 77 78 a.GenericAdmission.AddFlags(fs) 79} 80 81// Validate verifies flags passed to kube-apiserver AdmissionOptions. 82// Kube-apiserver verifies PluginNames and then call generic AdmissionOptions.Validate. 83func (a *AdmissionOptions) Validate() []error { 84 if a == nil { 85 return nil 86 } 87 var errs []error 88 if a.PluginNames != nil && 89 (a.GenericAdmission.EnablePlugins != nil || a.GenericAdmission.DisablePlugins != nil) { 90 errs = append(errs, fmt.Errorf("admission-control and enable-admission-plugins/disable-admission-plugins flags are mutually exclusive")) 91 } 92 93 registeredPlugins := sets.NewString(a.GenericAdmission.Plugins.Registered()...) 94 for _, name := range a.PluginNames { 95 if !registeredPlugins.Has(name) { 96 errs = append(errs, fmt.Errorf("admission-control plugin %q is unknown", name)) 97 } 98 } 99 100 errs = append(errs, a.GenericAdmission.Validate()...) 101 102 return errs 103} 104 105// ApplyTo adds the admission chain to the server configuration. 106// Kube-apiserver just call generic AdmissionOptions.ApplyTo. 107func (a *AdmissionOptions) ApplyTo( 108 c *server.Config, 109 informers informers.SharedInformerFactory, 110 kubeAPIServerClientConfig *rest.Config, 111 features featuregate.FeatureGate, 112 pluginInitializers ...admission.PluginInitializer, 113) error { 114 if a == nil { 115 return nil 116 } 117 118 if a.PluginNames != nil { 119 // pass PluginNames to generic AdmissionOptions 120 a.GenericAdmission.EnablePlugins, a.GenericAdmission.DisablePlugins = computePluginNames(a.PluginNames, a.GenericAdmission.RecommendedPluginOrder) 121 } 122 123 return a.GenericAdmission.ApplyTo(c, informers, kubeAPIServerClientConfig, features, pluginInitializers...) 124} 125 126// explicitly disable all plugins that are not in the enabled list 127func computePluginNames(explicitlyEnabled []string, all []string) (enabled []string, disabled []string) { 128 return explicitlyEnabled, sets.NewString(all...).Difference(sets.NewString(explicitlyEnabled...)).List() 129} 130