Cobra: child command is not calling the parents PersistentPreRun function

[algrebe]

Hi, I've been reading the documentation on the readme that says that the When the subcommand is executed, it will run the root command's PersistentPreRun but not the root command's PersistentPostRun , but the PersistentPreRun isn't getting executed.

package main

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

func main() {
    var rootCmd = &cobra.Command{
        Use:   "root [sub]",
        Short: "My root command",
        PersistentPreRun: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside rootCmd PersistentPreRun with args: %v\n", args)
        },
        PreRun: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside rootCmd PreRun with args: %v\n", args)
        },
        Run: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside rootCmd Run with args: %v\n", args)
        },
        PostRun: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside rootCmd PostRun with args: %v\n", args)
        },
        PersistentPostRun: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside rootCmd PersistentPostRun with args: %v\n", args)
        },
    }

    var subCmd = &cobra.Command{
        Use:   "sub [no options!]",
        Short: "My subcommand",
        PersistentPreRun: func(cmd *cobra.Command, args []string) {
                fmt.Printf("Inside subCmd PersistentPreRun with args: %v\n", args)
        },
        PreRun: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside subCmd PreRun with args: %v\n", args)
        },
        Run: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside subCmd Run with args: %v\n", args)
        },
        PostRun: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside subCmd PostRun with args: %v\n", args)
        },
        PersistentPostRun: func(cmd *cobra.Command, args []string) {
            fmt.Printf("Inside subCmd PersistentPostRun with args: %v\n", args)
        },
    }

    rootCmd.AddCommand(subCmd)
    _ = rootCmd.Execute()
}

root@vagrant-ubuntu-vivid-64:/tmp# go version
go version go1.5.2 linux/amd64

root@vagrant-ubuntu-vivid-64:/tmp# go build test.go

root@vagrant-ubuntu-vivid-64:/tmp# ./test 
Inside rootCmd PersistentPreRun with args: []
Inside rootCmd PreRun with args: []
Inside rootCmd Run with args: []
Inside rootCmd PostRun with args: []
Inside rootCmd PersistentPostRun with args: []

root@vagrant-ubuntu-vivid-64:/tmp# ./test sub arg1 arg2 arg3
Inside subCmd PersistentPreRun with args: [arg1 arg2 arg3]
Inside subCmd PreRun with args: [arg1 arg2 arg3]
Inside subCmd Run with args: [arg1 arg2 arg3]
Inside subCmd PostRun with args: [arg1 arg2 arg3]
Inside subCmd PersistentPostRun with args: [arg1 arg2 arg3]

the second example should have also had the output "Inside rootCmd PersistentPreRun" right ?

[eparis]

No, you overwrote the PersistentPreRun in the subcommand. If you didn't define a PersistentPreRun in the subcommand, as in the README, then the root PersistentPreRun would be run...

[algrebe]

@eparis Is there any way of chaining PersistentPreRuns ? I'd like it to run the parent and then the child.

[eparis]

Today the only option is to call the parent pre run in your pre run. Patches to cobra to allow persistent chaining would be welcome :)

[algrebe]

@eparis thank you. I've already got something working.I would like to know what would gel well with your existing naming convention.
Right now I have PreRunChain and PreRunChainE and PostRunChain and PostRunChainE

[Julio-Guerra]

Just fell into this trap too. As the commands are structured into a tree, it makes unnatural not calling {Pre, Post}*Run() during a tree walk. So at least it should be documented as ""do it yourself ;)

[lucymhdavies]

Came across this issue myself.

This suggestion is the way to go:

Today the only option is to call the parent pre run in your pre run. Patches to cobra to allow persistent chaining would be welcome :)

As an example, I added this to my child command's PersistentPreRun:

// Call parent pre-run
if rootCmd.PersistentPreRun != nil {
    rootCmd.PersistentPreRun(cmd, args)
}

[justinfx]

Just got caught out on this as well and found this thread. I didn't want my subcommand to have direct knowledge of an ancestor command so I did something like this:

func callPersistentPreRun(cmd *cobra.Command, args []string) { 
    if parent := cmd.Parent(); parent != nil { 
        if parent.PersistentPreRun != nil { 
            parent.PersistentPreRun(parent, args) 
        } 
    } 
} 

sub := &cobra.Command{ 
    ... 
    PersistentPreRun: func(cmd *cobra.Command, args []string) { 
        callPersistentPreRun(cmd, args) 
        ... 
    }, 
},