feat: option to add own IP api, and better error checks

cmd/simple-ddns-client/main.go

@@ -18,18 +18,17 @@ this program. If not, see <https://www.gnu.org/licenses/>.
 package main
 
 import (
-	"bytes"
 	"context"
 	"encoding/json"
 	"flag"
 	"fmt"
-	"io"
 	"log"
 	"net"
-	"net/http"
 	"os"
 	"strings"
 	"time"
+
+	utils "git.nadeko.net/fijxu/simple-ddns-client/internal"
 )
 
 type Porkbun struct {
@@ -53,10 +52,10 @@ type Config struct {
 	UpdateInterval int     `json:"updateInterval"`
 	Provider       string  `json:"provider"`
 	DnsServer      string  `json:"dnsServer"`
+	PublicIpApi    string  `json:"publicIpApi"`
 	Porkbun        Porkbun `json:"porkbun"`
 }
 
-var client *http.Client
 var config *Config
 
 // https://stackoverflow.com/questions/59889882/specifying-dns-server-for-lookup-in-go
@@ -80,22 +79,32 @@ var resolver = &net.Resolver{
 
 // TODO: Use UPNP, NAT-PMP or with PCP
 func getIpAddress() string {
-	req := doGetRequest("https://api.ipify.org")
+	req, err := utils.DoGetRequest(config.PublicIpApi)
+	if err != nil {
+		log.Print("Failed to retrieve public ip address from " + config.PublicIpApi + ": " + err.Error())
+		return ""
+	}
 	return string(req)
 }
 
 func (p *Porkbun) updateIp() {
 	dnsIp, err := resolver.LookupHost(context.Background(), p.Domain)
 	if err != nil {
-		log.Print("Failed to retrieve IP address for domain " + p.Domain)
+		log.Print("Failed to retrieve IP address for domain " + p.Domain + ": " + err.Error())
+		return
 	}
-
-	log.Print("Current IP of the record " + p.Domain + " is " + dnsIp[0])
+	if len(dnsIp) > 1 {
+		log.Fatal("The record '" + p.Domain + "' can't contain more than 1 IP address!")
+	}
+	if string(dnsIp[0]) == p.Data.Ip {
+		log.Print("No need to update the IP address of domain '" + p.Domain + "'. IP is already " + p.Data.Ip)
+		return
+	}
+	log.Print("Current IP of the record '" + p.Domain + "' is " + dnsIp[0])
 
 	p.Data.Ip = getIpAddress()
-
-	if string(dnsIp[0]) == p.Data.Ip {
-		log.Print("No need to update the IP address of domain " + p.Domain + ". IP is already " + p.Data.Ip)
+	if p.Data.Ip == "" {
+		log.Print("Failed to retrieve current public IP address")
 		return
 	}
 
@@ -111,7 +120,11 @@ func (p *Porkbun) updateIp() {
 	data, _ := json.Marshal(&p.Data)
 	queryUrl := domain + "/" + p.Type + "/" + subDomain
 
-	res := doPostRequest("https://api.porkbun.com/api/json/v3/dns/editByNameType/"+queryUrl, data)
+	res, err := utils.DoPostRequest("https://api.porkbun.com/api/json/v3/dns/editByNameType/"+queryUrl, data)
+	if err != nil {
+		log.Print("Failed to update public IP address: " + err.Error())
+		return
+	}
 
 	// Porkbun returns `{"status":"SUCCESS"}` if the IP address has been
 	// updated successfully
@@ -145,40 +158,7 @@ func loadConfig(configPath string) *Config {
 	return config
 }
 
-func doGetRequest(url string) []byte {
-	request, err := http.NewRequest("GET", url, nil)
-	if err != nil {
-		log.Fatal(err.Error())
-	}
-	res, err := client.Do(request)
-	if err != nil {
-		log.Fatal(err.Error())
-	}
-	defer res.Body.Close()
-
-	body, err := io.ReadAll(res.Body)
-
-	return body
-}
-
-func doPostRequest(url string, data []byte) []byte {
-	request, err := http.NewRequest("POST", url, bytes.NewBuffer(data))
-	if err != nil {
-		log.Fatal(err.Error())
-	}
-	res, err := client.Do(request)
-	if err != nil {
-		log.Fatal(err.Error())
-	}
-	defer res.Body.Close()
-
-	body, err := io.ReadAll(res.Body)
-
-	return body
-}
-
 func init() {
-	client = &http.Client{}
 	var configPath string
 
 	flag.StringVar(&configPath, "c", "/etc/simple-ddns-client/config.json", "config.json path")

config.json.example

@@ -2,6 +2,7 @@
 	"updateInterval": 60,
 	"dnsServer": "1.1.1.1:53",
 	"provider": "porkbun",
+	"publicIpApi": "https://api.ipify.org",
 	"porkbun": {
 		"apiKey": "pk1_xxx",
 		"secretApiKey": "sk1_xxx",

go.mod

@@ -1,3 +1,3 @@
-module git.nadeko.net/simple-ddns-client
+module git.nadeko.net/fijxu/simple-ddns-client
 
 go 1.23.4

internal/utils.go

@@ -0,0 +1,49 @@
+package utils
+
+import (
+	"bytes"
+	"io"
+	"net/http"
+)
+
+var client = &http.Client{}
+
+func DoGetRequest(url string) ([]byte, error) {
+	request, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	res, err := client.Do(request)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	return body, nil
+}
+
+func DoPostRequest(url string, data []byte) ([]byte, error) {
+	request, err := http.NewRequest("POST", url, bytes.NewBuffer(data))
+	if err != nil {
+		return nil, err
+	}
+
+	res, err := client.Do(request)
+	if err != nil {
+		return nil, err
+	}
+	defer res.Body.Close()
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	return body, nil
+}