Golang基于Digital Ocean DNS的个人动态域名解析插件DDNS的使用

什么是DDNS

动态DNS(DDNS)是一种自动更新域名系统(DNS)中名称服务器的方法，通常实时更新其配置的主机名、地址或其他信息。

动机

虽然有DynDNS、No-IP等服务可以远程访问PC，但我们真的需要它们吗？这是一个免费的DDNS解决方案(感谢Digital Ocean Networking DNS)。

安装

从发布页面下载二进制文件，并启动它：

ddns

或者使用Docker镜像：

docker run \
  -v /path/to/config.yml:/config/ddns.yml \
  skibish/ddns -conf-file /config/ddns.yml

文档

运行ddns -h查看帮助，输出如下：

Usage of ./ddns:
  -conf-file string
        Location of the configuration file. If not provided, searches current directory, then $HOME for ddns.yml file
  -ver
        Show version

你需要在Digital Ocean Networks面板中设置你的域名，并在域名提供商配置中将域名指向Digital Ocean NS记录。

配置文件示例

ddns.yml配置文件示例：

# DDNS configuration file.

# Mandatory, DigitalOcean API token.
# It can be also set using environment variable DDNS_TOKEN.
token: ""

# By default, IP check occurs every 5 minutes.
# It can be also set using environment variable DDNS_CHECKPERIOD.
checkPeriod: "5m"

# By default, timeout to external resources is set to 10 seconds.
# It can be also set using environment variable DDNS_REQUESTTIMEOUT.
requestTimeout: "10s"

# By default, IPv6 address is not requested.
# IPv6 address can be forced by setting it to `true`.
# It can be also set using environment variable DDNS_IPV6.
ipv6: false

# List of domains and their records to update.
domains:
  example.com:
  # More details about the fields can be found here:
  # https://developers.digitalocean.com/documentation/v2/#create-a-new-domain-record
  - type: "A"
    name: "www"
  - type: "TXT"
    name: "demo"

    # By default, is set to "{{.IP}}" (key .IP is reserved).
    # Supports Go template engine.
    # Additional keys can be set in "params" block below.
    data: "My IP is {{.IP}} and I am {{.mood}}"

    # By default, 1800 seconds (5 minutes).
    ttl: 1800

# By default, params is empty.
params:
  mood: "cool"

# By default, notifications is empty.
notifications:

  # Gotify (https://gotify.net)
- type: "gotify"
  app_url: "https://gotify.example.com"
  app_token: ""
  title: "DDNS" 

  # SMTP
- type: "smtp"
  user: "foo@bar.com"
  password: "1234"
  host: "localhost"
  port: "468"
  from: "bar@foo.com"
  to: "foo@foo.com"
  subject: "My DDNS sending me a message"

  # Telegram (https://telegram.org)
- type: "telegram"
  token: "telegram bot token"
  chat_id: "1234"

Go代码示例

以下是一个简单的Go代码示例，展示如何使用Digital Ocean API更新DNS记录：

package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/digitalocean/godo"
	"golang.org/x/oauth2"
)

// TokenSource 实现了oauth2.TokenSource接口
type TokenSource struct {
	AccessToken string
}

// Token 返回一个oauth2.Token
func (t *TokenSource) Token() (*oauth2.Token, error) {
	token := &oauth2.Token{
		AccessToken: t.AccessToken,
	}
	return token, nil
}

func main() {
	// 设置Digital Ocean API token
	token := "your_digital_ocean_token"
	
	// 创建OAuth2 token源
	tokenSource := &TokenSource{
		AccessToken: token,
	}
	
	// 创建OAuth2客户端
	oauthClient := oauth2.NewClient(context.Background(), tokenSource)
	
	// 创建Digital Ocean客户端
	client := godo.NewClient(oauthClient)
	
	// 设置域名和记录
	domain := "example.com"
	recordName := "www"
	recordType := "A"
	recordData := "192.168.1.1" // 这里应该是你的当前IP地址
	recordTTL := 1800
	
	// 创建DNS记录
	createRequest := &godo.DomainRecordEditRequest{
		Type: recordType,
		Name: recordName,
		Data: recordData,
		TTL:  recordTTL,
	}
	
	// 调用API创建记录
	ctx := context.TODO()
	record, _, err := client.Domains.CreateRecord(ctx, domain, createRequest)
	if err != nil {
		log.Fatalf("Error creating DNS record: %v", err)
	}
	
	fmt.Printf("Created DNS record: %+v\n", record)
	
	// 定期检查并更新IP
	ticker := time.NewTicker(5 * time.Minute)
	defer ticker.Stop()
	
	for range ticker.C {
		// 这里应该获取当前IP地址
		newIP := "192.168.1.1" // 替换为获取当前IP的逻辑
		
		// 更新DNS记录
		updateRequest := &godo.DomainRecordEditRequest{
			Type: recordType,
			Name: recordName,
			Data: newIP,
			TTL:  recordTTL,
		}
		
		_, _, err := client.Domains.EditRecord(ctx, domain, record.ID, updateRequest)
		if err != nil {
			log.Printf("Error updating DNS record: %v", err)
			continue
		}
		
		fmt.Printf("Updated DNS record with new IP: %s\n", newIP)
	}
}

这个示例展示了如何使用Digital Ocean的Go客户端库创建和更新DNS记录。在实际应用中，你需要添加获取当前IP地址的逻辑，并处理错误情况。