Matteo Scandolo | a428586 | 2020-12-01 18:10:10 -0800 | [diff] [blame] | 1 | /* |
| 2 | Copyright 2014 The Kubernetes Authors. |
| 3 | |
| 4 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | you may not use this file except in compliance with the License. |
| 6 | You may obtain a copy of the License at |
| 7 | |
| 8 | http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | |
| 10 | Unless required by applicable law or agreed to in writing, software |
| 11 | distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | See the License for the specific language governing permissions and |
| 14 | limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package clientcmd |
| 18 | |
| 19 | import ( |
| 20 | "io" |
| 21 | "sync" |
| 22 | |
| 23 | "k8s.io/klog/v2" |
| 24 | |
| 25 | restclient "k8s.io/client-go/rest" |
| 26 | clientcmdapi "k8s.io/client-go/tools/clientcmd/api" |
| 27 | ) |
| 28 | |
| 29 | // DeferredLoadingClientConfig is a ClientConfig interface that is backed by a client config loader. |
| 30 | // It is used in cases where the loading rules may change after you've instantiated them and you want to be sure that |
| 31 | // the most recent rules are used. This is useful in cases where you bind flags to loading rule parameters before |
| 32 | // the parse happens and you want your calling code to be ignorant of how the values are being mutated to avoid |
| 33 | // passing extraneous information down a call stack |
| 34 | type DeferredLoadingClientConfig struct { |
| 35 | loader ClientConfigLoader |
| 36 | overrides *ConfigOverrides |
| 37 | fallbackReader io.Reader |
| 38 | |
| 39 | clientConfig ClientConfig |
| 40 | loadingLock sync.Mutex |
| 41 | |
| 42 | // provided for testing |
| 43 | icc InClusterConfig |
| 44 | } |
| 45 | |
| 46 | // InClusterConfig abstracts details of whether the client is running in a cluster for testing. |
| 47 | type InClusterConfig interface { |
| 48 | ClientConfig |
| 49 | Possible() bool |
| 50 | } |
| 51 | |
| 52 | // NewNonInteractiveDeferredLoadingClientConfig creates a ConfigClientClientConfig using the passed context name |
| 53 | func NewNonInteractiveDeferredLoadingClientConfig(loader ClientConfigLoader, overrides *ConfigOverrides) ClientConfig { |
| 54 | return &DeferredLoadingClientConfig{loader: loader, overrides: overrides, icc: &inClusterClientConfig{overrides: overrides}} |
| 55 | } |
| 56 | |
| 57 | // NewInteractiveDeferredLoadingClientConfig creates a ConfigClientClientConfig using the passed context name and the fallback auth reader |
| 58 | func NewInteractiveDeferredLoadingClientConfig(loader ClientConfigLoader, overrides *ConfigOverrides, fallbackReader io.Reader) ClientConfig { |
| 59 | return &DeferredLoadingClientConfig{loader: loader, overrides: overrides, icc: &inClusterClientConfig{overrides: overrides}, fallbackReader: fallbackReader} |
| 60 | } |
| 61 | |
| 62 | func (config *DeferredLoadingClientConfig) createClientConfig() (ClientConfig, error) { |
| 63 | config.loadingLock.Lock() |
| 64 | defer config.loadingLock.Unlock() |
| 65 | |
| 66 | if config.clientConfig != nil { |
| 67 | return config.clientConfig, nil |
| 68 | } |
| 69 | mergedConfig, err := config.loader.Load() |
| 70 | if err != nil { |
| 71 | return nil, err |
| 72 | } |
| 73 | |
| 74 | var currentContext string |
| 75 | if config.overrides != nil { |
| 76 | currentContext = config.overrides.CurrentContext |
| 77 | } |
| 78 | if config.fallbackReader != nil { |
| 79 | config.clientConfig = NewInteractiveClientConfig(*mergedConfig, currentContext, config.overrides, config.fallbackReader, config.loader) |
| 80 | } else { |
| 81 | config.clientConfig = NewNonInteractiveClientConfig(*mergedConfig, currentContext, config.overrides, config.loader) |
| 82 | } |
| 83 | return config.clientConfig, nil |
| 84 | } |
| 85 | |
| 86 | func (config *DeferredLoadingClientConfig) RawConfig() (clientcmdapi.Config, error) { |
| 87 | mergedConfig, err := config.createClientConfig() |
| 88 | if err != nil { |
| 89 | return clientcmdapi.Config{}, err |
| 90 | } |
| 91 | |
| 92 | return mergedConfig.RawConfig() |
| 93 | } |
| 94 | |
| 95 | // ClientConfig implements ClientConfig |
| 96 | func (config *DeferredLoadingClientConfig) ClientConfig() (*restclient.Config, error) { |
| 97 | mergedClientConfig, err := config.createClientConfig() |
| 98 | if err != nil { |
| 99 | return nil, err |
| 100 | } |
| 101 | |
| 102 | // load the configuration and return on non-empty errors and if the |
| 103 | // content differs from the default config |
| 104 | mergedConfig, err := mergedClientConfig.ClientConfig() |
| 105 | switch { |
| 106 | case err != nil: |
| 107 | if !IsEmptyConfig(err) { |
| 108 | // return on any error except empty config |
| 109 | return nil, err |
| 110 | } |
| 111 | case mergedConfig != nil: |
| 112 | // the configuration is valid, but if this is equal to the defaults we should try |
| 113 | // in-cluster configuration |
| 114 | if !config.loader.IsDefaultConfig(mergedConfig) { |
| 115 | return mergedConfig, nil |
| 116 | } |
| 117 | } |
| 118 | |
| 119 | // check for in-cluster configuration and use it |
| 120 | if config.icc.Possible() { |
| 121 | klog.V(4).Infof("Using in-cluster configuration") |
| 122 | return config.icc.ClientConfig() |
| 123 | } |
| 124 | |
| 125 | // return the result of the merged client config |
| 126 | return mergedConfig, err |
| 127 | } |
| 128 | |
| 129 | // Namespace implements KubeConfig |
| 130 | func (config *DeferredLoadingClientConfig) Namespace() (string, bool, error) { |
| 131 | mergedKubeConfig, err := config.createClientConfig() |
| 132 | if err != nil { |
| 133 | return "", false, err |
| 134 | } |
| 135 | |
| 136 | ns, overridden, err := mergedKubeConfig.Namespace() |
| 137 | // if we get an error and it is not empty config, or if the merged config defined an explicit namespace, or |
| 138 | // if in-cluster config is not possible, return immediately |
| 139 | if (err != nil && !IsEmptyConfig(err)) || overridden || !config.icc.Possible() { |
| 140 | // return on any error except empty config |
| 141 | return ns, overridden, err |
| 142 | } |
| 143 | |
| 144 | if len(ns) > 0 { |
| 145 | // if we got a non-default namespace from the kubeconfig, use it |
| 146 | if ns != "default" { |
| 147 | return ns, false, nil |
| 148 | } |
| 149 | |
| 150 | // if we got a default namespace, determine whether it was explicit or implicit |
| 151 | if raw, err := mergedKubeConfig.RawConfig(); err == nil { |
| 152 | // determine the current context |
| 153 | currentContext := raw.CurrentContext |
| 154 | if config.overrides != nil && len(config.overrides.CurrentContext) > 0 { |
| 155 | currentContext = config.overrides.CurrentContext |
| 156 | } |
| 157 | if context := raw.Contexts[currentContext]; context != nil && len(context.Namespace) > 0 { |
| 158 | return ns, false, nil |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | klog.V(4).Infof("Using in-cluster namespace") |
| 164 | |
| 165 | // allow the namespace from the service account token directory to be used. |
| 166 | return config.icc.Namespace() |
| 167 | } |
| 168 | |
| 169 | // ConfigAccess implements ClientConfig |
| 170 | func (config *DeferredLoadingClientConfig) ConfigAccess() ConfigAccess { |
| 171 | return config.loader |
| 172 | } |