gist for github.com/spf13/cobra describing the use of persistent chaining

persistent_chaining.go

package main

import (
	"fmt"
	"github.com/spf13/cobra"
)

func getFunc(msg string) func(*cobra.Command, []string) {
	return func(cmd *cobra.Command, args []string) {
		fmt.Printf("%s with args %v\n", msg, args)
	}
}

func getSubCmd1() *cobra.Command {
	cmd := &cobra.Command{
		Use:               "cmd1",
		Short:             "cmd1",
		PersistentPreRun:  getFunc("inside cmd1 PersistentPreRun"),
		PreRun:            getFunc("inside cmd1 PreRun"),
		Run:               getFunc("inside cmd1 Run"),
		PostRun:           getFunc("inside cmd1 PostRun"),
		PersistentPostRun: getFunc("inside cmd1 PersistentPostRun"),
	}
	return cmd
}

func getSubCmd2() *cobra.Command {
	cmd := &cobra.Command{
		Use:               "cmd2",
		Short:             "cmd2",
		PreRun:            getFunc("inside cmd2 PreRun"),
		Run:               getFunc("inside cmd2 Run"),
		PostRun:           getFunc("inside cmd2 PostRun"),
		PersistentPostRun: getFunc("inside cmd2 PersistentPostRun"),
	}
	return cmd
}

func getRootCmd() *cobra.Command {
	cmd := &cobra.Command{
		Use:               "test-cobra-chain",
		Short:             "test-cobra-chain",
		PersistentPreRun:  getFunc("inside root PersistentPreRun"),
		PreRun:            getFunc("inside root PreRun"),
		Run:               getFunc("inside root Run"),
		PostRun:           getFunc("inside root PostRun"),
		PersistentPostRun: getFunc("inside root PersistentPostRun"),
	}
	return cmd
}

func main() {
	rootCmd := getRootCmd()
	subCmd1 := getSubCmd1()
	subCmd2 := getSubCmd2()

	subCmd1.AddCommand(subCmd2)
	rootCmd.AddCommand(subCmd1)
	rootCmd.Execute()
}

func init() {
	// nothing done
}

After a slight modification to the gist, i.e.

func init() {
    if err := cobra.EnableChainHooks(); err != nil {
        panic(err)
    }
}

Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ # added EnableChainHooks function to init()
Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ go build
Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ ls
cobrat  main.go
Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ ./cobrat
inside root PersistentPreRun with args []
inside root PreRun with args []
inside root Run with args []
inside root PostRun with args []
inside root PersistentPostRun with args []
Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ ./cobrat cmd1
inside root PersistentPreRun with args []
inside cmd1 PersistentPreRun with args []
inside cmd1 PreRun with args []
inside cmd1 Run with args []
inside cmd1 PostRun with args []
inside cmd1 PersistentPostRun with args []
inside root PersistentPostRun with args []
Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ ./cobrat cmd1 cmd2
inside root PersistentPreRun with args []
inside cmd1 PersistentPreRun with args []
inside cmd2 PreRun with args []
inside cmd2 Run with args []
inside cmd2 PostRun with args []
inside cmd2 PersistentPostRun with args []
inside cmd1 PersistentPostRun with args []
inside root PersistentPostRun with args []
Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ 

On adding an extra DisableChainHooks somewhere in main or wherever, you'll get the following

Dell-n411z:~/golang/default_ws/src/github.com/algrebe/cobrat$ ./cobrat cmd1 cmd2 arg1 arg2
panic: Toggle useChainHooks can be done only once !