本節重點總結 :
- newCmdCreate 調用cobra的Run函數
- 調用RunCreate構建resourceBuilder對象
- 調用visit方法創建資源
- 底層使用resetclient 和k8s-api通信
架構圖
![kubectl_create.png]()
create的流程 NewCmdCreate
- 代碼入口 D:\go_path\src\github.com\kubernetes\kubernetes\staging\src\k8s.io\kubectl\pkg\cmd\create\create.go
創建Create選項對象
o := NewCreateOptions(ioStreams)
初始化cmd
cmd := &cobra.Command{
Use: "create -f FILENAME",
DisableFlagsInUseLine: true,
Short: i18n.T("Create a resource from a file or from stdin"),
Long: createLong,
Example: createExample,
Run: func(cmd *cobra.Command, args []string) {
if cmdutil.IsFilenameSliceEmpty(o.FilenameOptions.Filenames, o.FilenameOptions.Kustomize) {
ioStreams.ErrOut.Write([]byte("Error: must specify one of -f and -k\n\n"))
defaultRunFunc := cmdutil.DefaultSubCommandRun(ioStreams.ErrOut)
defaultRunFunc(cmd, args)
return
}
cmdutil.CheckErr(o.Complete(f, cmd))
cmdutil.CheckErr(o.ValidateArgs(cmd, args))
cmdutil.CheckErr(o.RunCreate(f, cmd))
},
}
設置選項
// bind flag structs
o.RecordFlags.AddFlags(cmd)
usage := "to use to create the resource"
cmdutil.AddFilenameOptionFlags(cmd, &o.FilenameOptions, usage)
cmdutil.AddValidateFlags(cmd)
cmd.Flags().BoolVar(&o.EditBeforeCreate, "edit", o.EditBeforeCreate, "Edit the API resource before creating")
cmd.Flags().Bool("windows-line-endings", runtime.GOOS == "windows",
"Only relevant if --edit=true. Defaults to the line ending native to your platform.")
cmdutil.AddApplyAnnotationFlags(cmd)
cmdutil.AddDryRunFlag(cmd)
cmd.Flags().StringVarP(&o.Selector, "selector", "l", o.Selector, "Selector (label query) to filter on, supports '=', '==', and '!='.(e.g. -l key1=value1,key2=value2)")
cmd.Flags().StringVar(&o.Raw, "raw", o.Raw, "Raw URI to POST to the server. Uses the transport specified by the kubeconfig file.")
cmdutil.AddFieldManagerFlagVar(cmd, &o.fieldManager, "kubectl-create")
o.PrintFlags.AddFlags(cmd)
綁定創建子命令
// create subcommands
cmd.AddCommand(NewCmdCreateNamespace(f, ioStreams))
cmd.AddCommand(NewCmdCreateQuota(f, ioStreams))
cmd.AddCommand(NewCmdCreateSecret(f, ioStreams))
cmd.AddCommand(NewCmdCreateConfigMap(f, ioStreams))
cmd.AddCommand(NewCmdCreateServiceAccount(f, ioStreams))
cmd.AddCommand(NewCmdCreateService(f, ioStreams))
cmd.AddCommand(NewCmdCreateDeployment(f, ioStreams))
cmd.AddCommand(NewCmdCreateClusterRole(f, ioStreams))
cmd.AddCommand(NewCmdCreateClusterRoleBinding(f, ioStreams))
cmd.AddCommand(NewCmdCreateRole(f, ioStreams))
cmd.AddCommand(NewCmdCreateRoleBinding(f, ioStreams))
cmd.AddCommand(NewCmdCreatePodDisruptionBudget(f, ioStreams))
cmd.AddCommand(NewCmdCreatePriorityClass(f, ioStreams))
cmd.AddCommand(NewCmdCreateJob(f, ioStreams))
cmd.AddCommand(NewCmdCreateCronJob(f, ioStreams))
cmd.AddCommand(NewCmdCreateIngress(f, ioStreams))
核心的cmd.Run函數
校驗文件參數
if cmdutil.IsFilenameSliceEmpty(o.FilenameOptions.Filenames, o.FilenameOptions.Kustomize) {
ioStreams.ErrOut.Write([]byte("Error: must specify one of -f and -k\n\n"))
defaultRunFunc := cmdutil.DefaultSubCommandRun(ioStreams.ErrOut)
defaultRunFunc(cmd, args)
return
}
完善並填充所需字段
cmdutil.CheckErr(o.Complete(f, cmd))
校驗參數
cmdutil.CheckErr(o.ValidateArgs(cmd, args))
核心的RunCreate
- 位置 D:\go_path\src\github.com\kubernetes\kubernetes\staging\src\k8s.io\kubectl\pkg\cmd\create\create.go
cmdutil.CheckErr(o.RunCreate(f, cmd))
如果配置了apiserver的raw-uri就直接發送請求
if len(o.Raw) > 0 {
restClient, err := f.RESTClient()
if err != nil {
return err
}
return rawhttp.RawPost(restClient, o.IOStreams, o.Raw, o.FilenameOptions.Filenames[0])
}
如果配置了創建前 edit就執行 RunEditOnCreate
if o.EditBeforeCreate {
return RunEditOnCreate(f, o.PrintFlags, o.RecordFlags, o.IOStreams, cmd, &o.FilenameOptions, o.fieldManager)
}
根據配置中的validate決定是否開啓validate
- --validate=true: 使用一種模式校驗一下配置，模式是true的
- 意思是避免yaml中配置錯了
schema, err := f.Validator(cmdutil.GetFlagBool(cmd, "validate"))
if err != nil {
return err
}
根據命令行獲取namespace
cmdNamespace, enforceNamespace, err := f.ToRawKubeConfigLoader().Namespace()
if err != nil {
return err
}
構建builder對象
r := f.NewBuilder().
Unstructured().
Schema(schema).
ContinueOnError().
NamespaceParam(cmdNamespace).DefaultNamespace().
FilenameParam(enforceNamespace, &o.FilenameOptions).
LabelSelectorParam(o.Selector).
Flatten().
Do()
err = r.Err()
if err != nil {
return err
}
FilenameParam讀取配置文件
- 除了支持簡單的本地文件，也支持標準輸入和http/https協議訪問的文件，保存爲Visitor
- 代碼位置 D:\go_path\src\github.com\kubernetes\kubernetes\staging\src\k8s.io\cli-runtime\pkg\resource\builder.go
func (b *Builder) FilenameParam(enforceNamespace bool, filenameOptions *FilenameOptions) *Builder {
if errs := filenameOptions.validate(); len(errs) > 0 {
b.errs = append(b.errs, errs...)
return b
}
recursive := filenameOptions.Recursive
paths := filenameOptions.Filenames
for _, s := range paths {
switch {
case s == "-":
b.Stdin()
case strings.Index(s, "http://") == 0 || strings.Index(s, "https://") == 0:
url, err := url.Parse(s)
if err != nil {
b.errs = append(b.errs, fmt.Errorf("the URL passed to filename %q is not valid: %v", s, err))
continue
}
b.URL(defaultHttpGetAttempts, url)
default:
if !recursive {
b.singleItemImplied = true
}
b.Path(recursive, s)
}
}
if filenameOptions.Kustomize != "" {
b.paths = append(
b.paths,
&KustomizeVisitor{
mapper: b.mapper,
dirPath: filenameOptions.Kustomize,
schema: b.schema,
fSys: filesys.MakeFsOnDisk(),
})
}
if enforceNamespace {
b.RequireNamespace()
}
return b
}
調用visit函數創建資源
err = r.Visit(func(info *resource.Info, err error) error {
if err != nil {
return err
}
if err := util.CreateOrUpdateAnnotation(cmdutil.GetFlagBool(cmd, cmdutil.ApplyAnnotationsFlag), info.Object, scheme.DefaultJSONEncoder()); err != nil {
return cmdutil.AddSourceToErr("creating", info.Source, err)
}
if err := o.Recorder.Record(info.Object); err != nil {
klog.V(4).Infof("error recording current command: %v", err)
}
if o.DryRunStrategy != cmdutil.DryRunClient {
if o.DryRunStrategy == cmdutil.DryRunServer {
if err := o.DryRunVerifier.HasSupport(info.Mapping.GroupVersionKind); err != nil {
return cmdutil.AddSourceToErr("creating", info.Source, err)
}
}
obj, err := resource.
NewHelper(info.Client, info.Mapping).
DryRun(o.DryRunStrategy == cmdutil.DryRunServer).
WithFieldManager(o.fieldManager).
Create(info.Namespace, true, info.Object)
if err != nil {
return cmdutil.AddSourceToErr("creating", info.Source, err)
}
info.Refresh(obj, true)
}
- Create函數追蹤底層調用 createResource創建資源
- 位置 D:\go_path\src\github.com\kubernetes\kubernetes\staging\src\k8s.io\cli-runtime\pkg\resource\helper.go
func (m *Helper) createResource(c RESTClient, resource, namespace string, obj runtime.Object, options *metav1.CreateOptions) (runtime.Object, error) {
return c.Post().
NamespaceIfScoped(namespace, m.NamespaceScoped).
Resource(resource).
VersionedParams(options, metav1.ParameterCodec).
Body(obj).
Do(context.TODO()).
Get()
}
- 底層使用 restfulclient .post
- D:\go_path\src\github.com\kubernetes\kubernetes\staging\src\k8s.io\cli-runtime\pkg\resource\interfaces.go
type RESTClient interface {
Get() *rest.Request
Post() *rest.Request
Patch(types.PatchType) *rest.Request
Delete() *rest.Request
Put() *rest.Request
}
本節重點總結 :
- newCmdCreate 調用cobra的Run函數
- 調用RunCreate構建resourceBuilder對象
- 調用visit方法創建資源
- 底層使用resetclient 和k8s-api通信
