Kingpin independent commands pattern

cmd_infrastructure.go

package main

import (
	"fmt"

	"github.com/alecthomas/kingpin"
)

type cmd struct {
	*kingpin.CmdClause

	ActionFunc func()
	Name string
}

func addCommand(name string, help string) *cmd {
	cmdClause := kingpinApp.Command(name, help)
	return &cmd {
		CmdClause: cmdClause,
		Name: name,
	}
}

func (c *cmd) Action(action func()) {
	cmdActions[c.Name] = action
	c.ActionFunc = action
}

var cmdActions = make(map[string]func())

func runAction(name string) {
	actionFn, foundAction := cmdActions[name]
	if !foundAction {
		panic(fmt.Sprintf("Action not found: %s", name))
	}

	actionFn()
}

main.go

package main

import (
	"flag"
	"fmt"
	"os"

	"github.com/alecthomas/kingpin"
	"github.com/golang/glog"

	"ah.name/bookminer/util"
)

var kingpinApp = kingpin.New("cfb-cmd", "Computer finds books command runner")

func main() {
	flag.Parse()
	util.SetGlogConfig()
	glog.CopyStandardLogTo("WARNING")

	cmd, err := kingpinApp.Parse(flag.Args())
	if err != nil || cmd == "" {
		fmt.Fprintln(os.Stderr, err)
		kingpinApp.Usage(os.Stderr)
		flag.PrintDefaults()
		os.Exit(1)
	}

	runAction(cmd)
}

some_job.go

func init() {
	cmd := addCommand("refresh-watch", "Refresh a single watch")
	argWatchId := cmd.Arg("watch-id", "Id of watch to refresh").Required().Int64()
	cmd.Action(func() {
		watch.RefreshWatchById(*argWatchId)
	})
}