cloudflare-dns-updater/dns.go

package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
)

type IpResponse struct {
	Ip string `json:"ip"`
}

type DnsRecord struct {
	Id      string `json:"id"`
	Name    string `json:"name"`
	Type    string `json:"type"`
	Content string `json:"content"`
	Ttl     int    `json:"ttl"`
	Proxied bool   `json:"proxied"`
}

type DnsRecords struct {
	Result []DnsRecord `json:"result"`
}

func getIp() (string, error) {
	// Get IP from ipify and return it as a IpResponse

	ipUrl := "https://api.ipify.org?format=json"
	resp, err := http.Get(ipUrl)
	if err != nil {
		return "", err
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return "", err
	}

	var ipResponse IpResponse
	if err := json.Unmarshal(body, &ipResponse); err != nil {
		return "", err
	}
	return ipResponse.Ip, nil

}

type DnsUpdater struct {
	config *Config
}

func (d *DnsUpdater) CheckIfRecordsExist(recordName string) (DnsRecord, error) {
	cloudFlareUrl := "https://api.cloudflare.com/client/v4/zones/" + d.config.ZoneID + "/dns_records?name=" + recordName + "&type=A"
	log.Printf("CloudFlare URL: %s", cloudFlareUrl)

	req, err := http.NewRequest("GET", cloudFlareUrl, nil)
	if err != nil {
		return DnsRecord{}, err
	}
	req.Header.Set("X-Auth-Email", d.config.Email)
	req.Header.Set("Authorization", "Bearer "+d.config.AuthKey)
	req.Header.Set("Content-Type", "application/json")
	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return DnsRecord{}, err
	}
	defer resp.Body.Close()
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return DnsRecord{}, err
	}

	log.Printf("Body: %s", string(body))

	var dnsRecords DnsRecords
	if err := json.Unmarshal(body, &dnsRecords); err != nil {
		return DnsRecord{}, err
	}
	log.Printf("DNS Records: %+v", dnsRecords)

	// Check if the record exists
	for _, record := range dnsRecords.Result {
		if record.Name == recordName && record.Type == "A" {
			return record, nil
		}
	}
	return DnsRecord{}, nil
}

func (d *DnsUpdater) Update(record DnsRecord) error {
	ip, err := getIp()
	if err != nil {
		return err
	}
	if d.config.ForceIP != "" {
		ip = d.config.ForceIP
	}
	if record.Content == ip {
		return nil
	}

	record.Content = ip
	record.Ttl = 3600

	cloudFlareUrl := "https://api.cloudflare.com/client/v4/zones/" + d.config.ZoneID + "/dns_records/" + record.Id

	body, err := json.Marshal(record)
	if err != nil {
		return err
	}

	req, err := http.NewRequest("PATCH", cloudFlareUrl, bytes.NewBuffer(body))
	if err != nil {
		return err
	}
	req.Header.Set("X-Auth-Email", d.config.Email)
	req.Header.Set("Authorization", "Bearer "+d.config.AuthKey)
	req.Header.Set("Content-Type", "application/json")

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	body, err = io.ReadAll(resp.Body)
	if err != nil {
		return err
	}
	if resp.StatusCode != 200 {
		return fmt.Errorf("failed to update DNS: %s", string(body))
	}
	log.Printf("Updated DNS: %s", string(body))
	return nil
}

func (d *DnsUpdater) Create(recordName string) error {
	ip, err := getIp()
	if err != nil {
		return err
	}
	if d.config.ForceIP != "" {
		ip = d.config.ForceIP
	}
	record := DnsRecord{
		Name:    recordName,
		Type:    "A",
		Content: ip,
		Ttl:     3600,
		Proxied: false,
	}

	cloudFlareUrl := "https://api.cloudflare.com/client/v4/zones/" + d.config.ZoneID + "/dns_records"

	body, err := json.Marshal(record)
	if err != nil {
		return err
	}

	req, err := http.NewRequest("POST", cloudFlareUrl, bytes.NewBuffer(body))
	if err != nil {
		return err
	}
	req.Header.Set("X-Auth-Email", d.config.Email)
	req.Header.Set("Authorization", "Bearer "+d.config.AuthKey)
	req.Header.Set("Content-Type", "application/json")

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return err
	}
	defer resp.Body.Close()
	body, err = io.ReadAll(resp.Body)
	if err != nil {
		return err
	}
	if resp.StatusCode != 200 {
		return fmt.Errorf("failed to create DNS: %s", string(body))
	}
	log.Printf("Created DNS: %s", string(body))
	return nil
}