DDNSUpdater/main.go

98 lines
1.9 KiB
Go

package main
import (
"encoding/json"
"fmt"
"io/ioutil"
"net/http"
"os"
"strings"
"time"
)
type Config struct {
UpdateURL string `json:"update_url"`
CheckIntervalSecs int `json:"check_interval_seconds"`
IPCheckURL string `json:"ip_check_url"`
}
func loadConfig(path string) (*Config, error) {
data, err := ioutil.ReadFile(path)
if err != nil {
return nil, err
}
var cfg Config
err = json.Unmarshal(data, &cfg)
if err != nil {
return nil, err
}
return &cfg, nil
}
func getPublicIP(ipURL string) (string, error) {
resp, err := http.Get(ipURL)
if err != nil {
return "", err
}
defer resp.Body.Close()
body, err := ioutil.ReadAll(resp.Body)
if err != nil {
return "", err
}
return strings.TrimSpace(string(body)), nil
}
func updateDDNS(url string) error {
resp, err := http.Get(url)
if err != nil {
return err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
return fmt.Errorf("failed, status code %d", resp.StatusCode)
}
return nil
}
func main() {
cfg, err := loadConfig("config.json")
if err != nil {
fmt.Println("Failed to load config:", err)
os.Exit(1)
}
//var lastIP string
lastIP, err := getPublicIP(cfg.IPCheckURL)
if err != nil {
fmt.Println("Error getting intial public IP:", err)
lastIP = ""
} else {
fmt.Println(time.Now(), "Starting with current IP:", lastIP)
}
ticker := time.NewTicker(time.Duration(cfg.CheckIntervalSecs) * time.Second)
defer ticker.Stop()
for {
ip, err := getPublicIP(cfg.IPCheckURL)
if err != nil {
fmt.Println("Error getting public IP:", err)
} else if ip != lastIP {
fmt.Println(time.Now(), "IP changed to", ip)
if err := updateDDNS(cfg.UpdateURL); err != nil {
fmt.Println("Failed to update DDNS:", err)
} else {
fmt.Println(time.Now(), "DDNS updated successfully")
lastIP = ip
}
} else {
fmt.Println(time.Now(), "IP unchanged:", ip)
}
<-ticker.C
}
}