parse-json-flag.go

package main

import (
	"encoding/json"
	"flag"
	"fmt"
)

type Profile struct {
	Name     string
	Age      uint
	Verified bool
}

// new added
func (this *Profile) String() string {
	b, _ := json.Marshal(*this)
	return string(b)
}

// new added
func (this *Profile) Set(s string) error {
	return json.Unmarshal([]byte(s), this)
}

func main() {
	var version string

	var profile Profile
	flag.StringVar(&version, "setVersion", "1.0.0", "")
	flag.Var(&profile, "setProfile", "")
	flag.Parse()

	fmt.Println("version = ", version)
	fmt.Println("profile = ", profile)
}

If anyone is struggling with escaping the arguments, use:
go run . --setVersion 1 --setProfile \{\"name\":\"aa\",\"age\":22,\"verified\":true\}