feat: 添加自定义 DNS 解析器

cmd/flags/flag.go

@@ -19,4 +19,5 @@ var (
 	CFAccessClientID     string
 	CFAccessClientSecret string
 	MemoryIncludeCache   bool
+	CustomDNS            string
 )

cmd/root.go

@@ -7,6 +7,7 @@ import (
 	"os"
 
 	"github.com/komari-monitor/komari-agent/cmd/flags"
+	"github.com/komari-monitor/komari-agent/dnsresolver"
 	monitoring "github.com/komari-monitor/komari-agent/monitoring/unit"
 	"github.com/komari-monitor/komari-agent/server"
 	"github.com/komari-monitor/komari-agent/update"
@@ -20,6 +21,15 @@ var RootCmd = &cobra.Command{
 	Run: func(cmd *cobra.Command, args []string) {
 		log.Println("Komari Agent", update.CurrentVersion)
 		log.Println("Github Repo:", update.Repo)
+
+		// 设置自定义DNS解析器
+		if flags.CustomDNS != "" {
+			dnsresolver.SetCustomDNSServer(flags.CustomDNS)
+			log.Printf("Using custom DNS server: %s", flags.CustomDNS)
+		} else {
+			log.Printf("Using default DNS servers, primary: %s", dnsresolver.DNSServers[0])
+		}
+
 		// Auto discovery
 		if flags.AutoDiscoveryKey != "" {
 			err := handleAutoDiscovery()
@@ -100,5 +110,6 @@ func init() {
 	RootCmd.PersistentFlags().StringVar(&flags.CFAccessClientID, "cf-access-client-id", "", "Cloudflare Access Client ID")
 	RootCmd.PersistentFlags().StringVar(&flags.CFAccessClientSecret, "cf-access-client-secret", "", "Cloudflare Access Client Secret")
 	RootCmd.PersistentFlags().BoolVar(&flags.MemoryIncludeCache, "memory-include-cache", false, "Include cache/buffer in memory usage")
+	RootCmd.PersistentFlags().StringVar(&flags.CustomDNS, "custom-dns", "", "Custom DNS server to use (e.g. 8.8.8.8)")
 	RootCmd.PersistentFlags().ParseErrorsWhitelist.UnknownFlags = true
 }

dnsresolver/resolver.go

@@ -0,0 +1,132 @@
+package dnsresolver
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+var (
+	// DNS服务器列表，按优先级排序
+	DNSServers = []string{
+		"114.114.114.114:53", // 114DNS，中国大陆
+		"8.8.8.8:53",         // Google DNS，全球
+		"8.8.4.4:53",         // Google DNS备用，全球
+		"1.1.1.1:53",         // Cloudflare DNS，全球
+		"223.5.5.5:53",       // 阿里DNS，中国大陆
+		"119.29.29.29:53",    // DNSPod，中国大陆
+	}
+
+	// CustomDNSServer 自定义DNS服务器，可以通过命令行参数设置
+	CustomDNSServer string
+)
+
+// SetCustomDNSServer 设置自定义DNS服务器
+func SetCustomDNSServer(dnsServer string) {
+	if dnsServer != "" {
+		// 检查是否已包含端口，如果没有则添加默认端口53
+		if !strings.Contains(dnsServer, ":") {
+			dnsServer = dnsServer + ":53"
+		}
+		CustomDNSServer = dnsServer
+	}
+}
+
+// getCurrentDNSServer 获取当前要使用的DNS服务器
+func getCurrentDNSServer() string {
+	if CustomDNSServer != "" {
+		return CustomDNSServer
+	}
+	// 如果没有设置自定义DNS，返回默认的第一个
+	return DNSServers[0]
+}
+
+// GetCustomResolver 返回一个使用指定DNS服务器的解析器
+func GetCustomResolver() *net.Resolver {
+	return &net.Resolver{
+		PreferGo: true,
+		Dial: func(ctx context.Context, network, address string) (net.Conn, error) {
+			d := net.Dialer{
+				Timeout: 10 * time.Second,
+			}
+
+			// 尝试自定义DNS或默认DNS
+			dnsServer := getCurrentDNSServer()
+			conn, err := d.DialContext(ctx, "udp", dnsServer)
+			if err == nil {
+				return conn, nil
+			}
+
+			// 如果连接失败，尝试其他DNS服务器
+			for _, server := range DNSServers {
+				if server != dnsServer { // 避免重复尝试
+					conn, err := d.DialContext(ctx, "udp", server)
+					if err == nil {
+						return conn, nil
+					}
+				}
+			}
+
+			// 所有DNS服务器都失败，返回最后一次的错误
+			return nil, err
+		},
+	}
+}
+
+// GetHTTPClient 返回一个使用自定义DNS解析器的HTTP客户端
+func GetHTTPClient(timeout time.Duration) *http.Client {
+	if timeout <= 0 {
+		timeout = 30 * time.Second
+	}
+
+	customResolver := GetCustomResolver()
+
+	return &http.Client{
+		Transport: &http.Transport{
+			Proxy: http.ProxyFromEnvironment,
+			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
+				host, port, err := net.SplitHostPort(addr)
+				if err != nil {
+					return nil, err
+				}
+				ips, err := customResolver.LookupHost(ctx, host)
+				if err != nil {
+					return nil, err
+				}
+				for _, ip := range ips {
+					dialer := &net.Dialer{
+						Timeout:   30 * time.Second,
+						KeepAlive: 30 * time.Second,
+						DualStack: true,
+					}
+					conn, err := dialer.DialContext(ctx, network, net.JoinHostPort(ip, port))
+					if err == nil {
+						return conn, nil
+					}
+				}
+				return nil, fmt.Errorf("failed to dial to any of the resolved IPs")
+			},
+			MaxIdleConns:          10,
+			IdleConnTimeout:       90 * time.Second,
+			TLSHandshakeTimeout:   10 * time.Second,
+			ExpectContinueTimeout: 1 * time.Second,
+		},
+		Timeout: timeout,
+	}
+}
+
+// GetNetDialer 返回一个使用自定义DNS解析器的网络拨号器
+func GetNetDialer(timeout time.Duration) *net.Dialer {
+	if timeout <= 0 {
+		timeout = 5 * time.Second
+	}
+
+	return &net.Dialer{
+		Timeout:   timeout,
+		KeepAlive: 30 * time.Second,
+		Resolver:  GetCustomResolver(),
+	}
+}

monitoring/unit/ip.go

@@ -8,17 +8,17 @@ import (
 	"net/http"
 	"regexp"
 	"time"
+
+	"github.com/komari-monitor/komari-agent/dnsresolver"
 )
 
 var (
+	// 创建适用于IPv4和IPv6的HTTP客户端
 	ipv4HTTPClient = &http.Client{
 		Transport: &http.Transport{
 			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-				d := net.Dialer{
-					Timeout:   15 * time.Second,
-					KeepAlive: 30 * time.Second,
-				}
-				return d.DialContext(ctx, "tcp4", addr) // 锁v4防止出现问题
+				dialer := dnsresolver.GetNetDialer(15 * time.Second)
+				return dialer.DialContext(ctx, "tcp4", addr) // 锁v4防止出现问题
 			},
 			MaxIdleConns:          10,
 			IdleConnTimeout:       30 * time.Second,
@@ -30,11 +30,8 @@ var (
 	ipv6HTTPClient = &http.Client{
 		Transport: &http.Transport{
 			DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {
-				d := net.Dialer{
-					Timeout:   15 * time.Second,
-					KeepAlive: 30 * time.Second,
-				}
-				return d.DialContext(ctx, "tcp6", addr) // 锁v6防止出现问题
+				dialer := dnsresolver.GetNetDialer(15 * time.Second)
+				return dialer.DialContext(ctx, "tcp6", addr) // 锁v6防止出现问题
 			},
 			MaxIdleConns:          10,
 			IdleConnTimeout:       30 * time.Second,

server/basicInfo.go

@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/komari-monitor/komari-agent/cmd/flags"
+	"github.com/komari-monitor/komari-agent/dnsresolver"
 	monitoring "github.com/komari-monitor/komari-agent/monitoring/unit"
 	"github.com/komari-monitor/komari-agent/update"
 )
@@ -86,7 +87,9 @@ func tryUploadData(data map[string]interface{}) error {
 		req.Header.Set("CF-Access-Client-Secret", flags.CFAccessClientSecret)
 	}
 
-	client := &http.Client{}
+	// 使用dnsresolver获取自定义HTTP客户端
+	client := dnsresolver.GetHTTPClient(30 * time.Second)
+
 	resp, err := client.Do(req)
 	if err != nil {
 		return err

server/websocket.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/gorilla/websocket"
 	"github.com/komari-monitor/komari-agent/cmd/flags"
+	"github.com/komari-monitor/komari-agent/dnsresolver"
 	"github.com/komari-monitor/komari-agent/monitoring"
 	"github.com/komari-monitor/komari-agent/terminal"
 	"github.com/komari-monitor/komari-agent/ws"
@@ -90,8 +91,12 @@ func EstablishWebSocketConnection() {
 }
 
 func connectWebSocket(websocketEndpoint string) (*ws.SafeConn, error) {
+	// 使用dnsresolver获取自定义网络拨号器
+	netDialer := dnsresolver.GetNetDialer(5 * time.Second)
+
 	dialer := &websocket.Dialer{
 		HandshakeTimeout: 5 * time.Second,
+		NetDialContext:   netDialer.DialContext,
 	}
 
 	// 创建请求头并添加Cloudflare Access头部
@@ -159,8 +164,13 @@ func handleWebSocketMessages(conn *ws.SafeConn, done chan<- struct{}) {
 func establishTerminalConnection(token, id, endpoint string) {
 	endpoint = strings.TrimSuffix(endpoint, "/") + "/api/clients/terminal?token=" + token + "&id=" + id
 	endpoint = "ws" + strings.TrimPrefix(endpoint, "http")
+
+	// 使用dnsresolver获取自定义网络拨号器
+	netDialer := dnsresolver.GetNetDialer(5 * time.Second)
+
 	dialer := &websocket.Dialer{
 		HandshakeTimeout: 5 * time.Second,
+		NetDialContext:   netDialer.DialContext,
 	}
 
 	// 创建请求头并添加Cloudflare Access头部

update/update.go

@@ -3,11 +3,13 @@ package update
 import (
 	"fmt"
 	"log"
+	"net/http"
 	"os"
 	"strings"
 	"time"
 
 	"github.com/blang/semver"
+	"github.com/komari-monitor/komari-agent/dnsresolver"
 	"github.com/rhysd/go-github-selfupdate/selfupdate"
 )
 
@@ -45,7 +47,9 @@ func CheckAndUpdate() error {
 		return fmt.Errorf("failed to parse current version: %v", err)
 	}
 
-	// Create selfupdate configuration
+	// 使用dnsresolver创建自定义HTTP客户端并设置为全局默认客户端
+	// 这会影响所有HTTP请求，包括selfupdate库中的请求
+	http.DefaultClient = dnsresolver.GetHTTPClient(60 * time.Second) // Create selfupdate configuration
 	config := selfupdate.Config{}
 	updater, err := selfupdate.NewUpdater(config)
 	if err != nil {