cobra-cli 将所有参数和标志传递给可执行文件

Question

I have a cobra CLI for my own stuff. Now I want to add commonly used executables eg kubectl , calicoctl as subcommands which will consume all arguments and flags like

mywrapper kubectl get all --all-namespaces
mywrapper kubectl create deployment nginx --image=nginx --port=80

Reproduce cobra project

mkdir mywrapper; cd mywrapper; go mod init mywrapper; cobra-cli init .

And add a subcommand eg kubectl

cobra-cli add kubectl 

Then populate ./cmd/kubectl.go with

package cmd

import (
    "fmt"
    "os/exec"
    "strings"

    "github.com/spf13/cobra"
)

var kubectlCmd = &cobra.Command{
    Use:   "kubectl",
    Short: "run kubectl",
    Run: func(cmd *cobra.Command, args []string) {
        out, err := exec.Command("/bin/bash", "-c", fmt.Sprintf("kubectl %v", strings.Join(args, " "))).Output()
        if err != nil {
            fmt.Println(err)
        }
        fmt.Println(string(out))
    },
}

func init() {
    rootCmd.AddCommand(kubectlCmd)
}

I can now run kubectl command eg go run . kubectl get pods go run . kubectl get pods . But it fails when flags are added eg go run . kubectl get pods --selector app=nginx go run . kubectl get pods --selector app=nginx

Answer 1

Pass your flags after the -- . A double dash (--) is used to signify the end of command options. In our case it is required to distinguish between the flags passed to go and those that aren't. Everything after the double dash wont be considered to be go 's flags.

I tried with gcloud:

package cmd

import (
    "fmt"
    "os/exec"

    "github.com/spf13/cobra"
)

var gcloudCmd = &cobra.Command{
    Use:   "gcloud",
    Short: "run gcloud",
    Run: func(cmd *cobra.Command, args []string) {
        out, err := exec.Command("gcloud", args...).Output()
        if err != nil {
            fmt.Println(err)
        }
        fmt.Println(string(out))
    },
}

func init() {
    rootCmd.AddCommand(gcloudCmd)
}

Then tried:

$ go run . gcloud compute regions list -- --filter="id<1250"

NAME          CPUS  DISKS_GB  ADDRESSES  RESERVED_ADDRESSES  STATUS  TURNDOWN_DATE
asia-east1    0/24  0/4096    0/8        0/8                 UP
europe-west1  0/24  0/4096    0/8        0/8                 UP
us-central1   0/24  0/4096    0/8        0/8                 UP
us-east1      0/24  0/4096    0/8        0/8                 UP
us-west1      0/24  0/4096    0/8        0/8                 UP

Adding more flags:

$ go run . gcloud compute regions list -- --filter="id<1250" --format="table(name,id)"

NAME          ID
asia-east1    1220
europe-west1  1100
us-central1   1000
us-east1      1230
us-west1      1210