stck-nsq-msg/stck-nsq-msg.go

package stcknsqmsg

import (
	"encoding/json"
	"fmt"
	"net"
	"os"
	"stck/stck-nsq-msg/msg"

	"github.com/denisbrodbeck/machineid"
	"github.com/go-viper/mapstructure/v2"
)

type StckNsqMsg struct {
	Type string            `mapstructure:"type"`
	Data StckNsqMsgVariant `mapstructure:"data"`
}

type StckNsqMsgRaw struct {
	Type string                 `mapstructure:"type"`
	Data map[string]interface{} `mapstructure:"data"`
}

type StckNsqMsgVariant interface {
	MsgType() string
}

func (m *StckNsqMsg) ToString() (string, error) {
	b, err := json.Marshal(m)
	if err != nil {
		return "", err
	}
	return string(b), nil
}

func FromString(s string) (StckNsqMsg, error) {
	var rm StckNsqMsgRaw
	var m StckNsqMsg
	err := json.Unmarshal([]byte(s), &rm)
	if err != nil {
		return m, err
	}
	// Cast to strongly typed struct
	m.Type = rm.Type
	switch rm.Type {
	case msg.DeviceHeartbeatMsgType:
		var d msg.DeviceHeartbeatMsg
		err = mapstructure.Decode(rm.Data, &d)
		if err != nil {
			return m, err
		}
		m.Data = &d
	default:
		return m, fmt.Errorf("unknown message type: %s", rm.Type)
	}
	return m, nil
}

func DeviceIdMatches(id1, id2 string) bool {
	return id1 == id2 || id1 == "*" || id2 == "*"
}

func GetLocalIP() (net.IP, error) {
	ifaces, err := net.Interfaces()
	if err != nil {
		return nil, err
	}

	for _, iface := range ifaces {
		addrs, err := iface.Addrs()
		if err != nil {
			return nil, err
		}

		for _, addr := range addrs {
			var ip net.IP
			switch v := addr.(type) {
			case *net.IPNet:
				ip = v.IP
			case *net.IPAddr:
				ip = v.IP
			}

			if ip == nil || ip.IsLoopback() {
				continue
			}

			ip = ip.To4()
			if ip == nil {
				continue // not an ipv4 address
			}

			return ip, nil
		}
	}

	return nil, fmt.Errorf("no non-loopback IP address found")
}

func MakeUniqueMachineID() string {
	ip, err := GetLocalIP()
	if err != nil {
		fmt.Fprintf(os.Stderr, "get local IP failed: %v\n", err)
	}

	machineid, err := machineid.ProtectedID("unique")
	if err != nil {
		fmt.Fprintf(os.Stderr, "get machine ID failed: %v\n", err)
	}

	return fmt.Sprintf("%s-%s", ip.String(), machineid)
}