Support usage line when running as kubectl plugin #2017
Description
When running as a kubectl plugin[1] we want the help text to look like a builtin
kubectl command. For example if we create a program kubectl-cobra:
$ cat main.go
package main
import (
"fmt"
"github.com/spf13/cobra"
)
func main() {
root := &cobra.Command{
Use: "kubectl cobra",
}
sub := &cobra.Command{
Use: "subcmd",
Run: func(cmd *cobra.Command, args []string) {
fmt.Println("kubectl cobra subcmd")
},
}
root.AddCommand(sub)
root.Execute()
}When we run it we get unwanted output:
$ kubectl cobra
Usage:
kubectl [command]
Available Commands:
completion Generate the autocompletion script for the specified shell
help Help about any command
subcmd
Flags:
-h, --help help for kubectl
Use "kubectl [command] --help" for more information about a command.
$ kubectl cobra subcmd -h
Usage:
kubectl subcmd [flags]
Flags:
-h, --help help for subcmd
The wanted output:
$ kubectl cobra
Usage:
kubectl cobra [command]
Available Commands:
completion Generate the autocompletion script for the specified shell
help Help about any command
subcmd
Flags:
-h, --help help for kubectl cobra
Use "kubectl cobra [command] --help" for more information about a command.
$ kubectl cobra subcmd -h
Usage:
kubectl cobra subcmd [flags]
Flags:
-h, --help help for subcmd
The problem is we don't have a way to set the command name, it is guessed
best on the first word of the Use field. SetUsageFunc() and SetUsageTemplate()
are not helpful in fixing this issue since it require re-implementing too much
logic and template which a user really don't want to re-implement.
Maybe we need SetNameFunc(), or Name field?
Workaround
If can get the wanted output using:
root := &cobra.Command{
Use: "kubectl\u00A0cobra",
}It works for help output, but I did not check if this affects shell completion.
[1] https://kubernetes.io/docs/tasks/extend-kubectl/kubectl-plugins/