cmd/kubectl/kubectl.go
func main() {
...
command := cmd.NewDefaultKubectlCommand()
...
if err := command.Execute(); err != nil {
os.Exit(1)
}
}
pkg/kubectl/cmd/cmd.go中
func NewDefaultKubectlCommand() *cobra.Command {
return NewDefaultKubectlCommandWithArgs(NewDefaultPluginHandler(plugin.ValidPluginFilenamePrefixes), os.Args, os.Stdin, os.Stdout, os.Stderr)
}
func NewDefaultKubectlCommandWithArgs(pluginHandler PluginHandler, args []string, in io.Reader, out, errout io.Writer) *cobra.Command {
cmd := NewKubectlCommand(in, out, errout)
if pluginHandler == nil {
return cmd
}
if len(args) > 1 {
cmdPathPieces := args[1:]
// only look for suitable extension executables if
// the specified command does not already exist
if _, _, err := cmd.Find(cmdPathPieces); err != nil {
if err := HandlePluginCommand(pluginHandler, cmdPathPieces); err != nil {
fmt.Fprintf(errout, "%v\n", err)
os.Exit(1)
}
}
}
return cmd
}
func NewDefaultPluginHandler(validPrefixes []string) *DefaultPluginHandler {
return &DefaultPluginHandler{
ValidPrefixes: validPrefixes,
}
}
// Lookup implements PluginHandler
func (h *DefaultPluginHandler) Lookup(filename string) (string, bool) {
for _, prefix := range h.ValidPrefixes {
path, err := exec.LookPath(fmt.Sprintf("%s-%s", prefix, filename))
if err != nil || len(path) == 0 {
continue
}
return path, true
}
return "", false
}
func NewKubectlCommand(in io.Reader, out, err io.Writer) *cobra.Command {
...
cmds := &cobra.Command{
...
}
...
ioStreams := genericclioptions.IOStreams{In: in, Out: out, ErrOut: err}
...
groups := templates.CommandGroups{
...
}
...
groups.Add(cmds)
...
return cmds
}
vendor/k8s.io/kubectl/pkg/util/templates/command_groups.go中
type CommandGroups []CommandGroup
func (g CommandGroups) Add(c *cobra.Command) {
for _, group := range g {
c.AddCommand(group.Commands...)
}
}
