feat: add custom User-Agent support for subscription and template requests

Add --user-agent / -u CLI flag and user-agent config field to allow
customizing the User-Agent header when fetching subscriptions and
remote templates. This is useful for providers that require a specific
UA to access their subscription links.

Closes #23

README.md

@@ -20,7 +20,8 @@
   "group-type": "selector",
   "sort": "name",
   "sort-type": "asc",
-  "output": "./config.json"
+  "output": "./config.json",
+  "user-agent": "自定义 User-Agent"
 }
 ```
 

api/handler/convert.go

@@ -57,6 +57,7 @@ func Convert(c *gin.Context) {
 		data.SortKey,
 		data.SortType,
 		groupRules,
+		data.UserAgent,
 	)
 	if err != nil {
 		c.JSON(400, gin.H{

cmd/convert.go

@@ -25,6 +25,7 @@ var (
 	sortType      string
 	config        string
 	groupRules    string
+	userAgent     string
 )
 
 func init() {
@@ -40,6 +41,7 @@ func init() {
 	convertCmd.Flags().StringVarP(&sortType, "sort-type", "T", "", "sort type, asc or desc")
 	convertCmd.Flags().StringVarP(&config, "config", "c", "", "configuration file path")
 	convertCmd.Flags().StringVarP(&groupRules, "group-rules", "R", "", "group rules")
+	convertCmd.Flags().StringVarP(&userAgent, "user-agent", "u", "", "custom User-Agent for fetching subscriptions and remote templates")
 	RootCmd.AddCommand(convertCmd)
 }
 
@@ -71,6 +73,7 @@ func convertRun(cmd *cobra.Command, args []string) {
 		sortKey,
 		sortType,
 		groupRulesMap,
+		userAgent,
 	)
 	if err != nil {
 		fmt.Println("Conversion error:", err)
@@ -152,4 +155,7 @@ func mergeConfig(cfg model.ConvertRequest) {
 	if output == "" {
 		output = cfg.Output
 	}
+	if userAgent == "" {
+		userAgent = cfg.UserAgent
+	}
 }

common/convert.go

@@ -36,6 +36,7 @@ func Convert(
 	sortKey string,
 	sortType string,
 	groupRules map[string][]string,
+	userAgent string,
 ) (string, error) {
 	result := ""
 	var err error
@@ -44,7 +45,7 @@ func Convert(
 		groupType = C.TypeSelector
 	}
 
-	outbounds, err := ConvertSubscriptionsToSProxy(subscriptions)
+	outbounds, err := ConvertSubscriptionsToSProxy(subscriptions, userAgent)
 	if err != nil {
 		return "", err
 	}
@@ -104,7 +105,7 @@ func Convert(
 		outbounds = AddCountryGroup(outbounds, groupType, sortKey, sortType, groupRules)
 	}
 	if templatePath != "" {
-		templateData, err := ReadTemplate(templatePath)
+		templateData, err := ReadTemplate(templatePath, userAgent)
 		if err != nil {
 			return "", err
 		}
@@ -226,12 +227,12 @@ func AddCountryGroup(proxies []model.Outbound, groupType string, sortKey string,
 	return append(proxies, groups...)
 }
 
-func ReadTemplate(template string) (string, error) {
+func ReadTemplate(template string, userAgent string) (string, error) {
 	var data string
 	var err error
 	isNetworkFile, _ := regexp.MatchString(`^https?://`, template)
 	if isNetworkFile {
-		data, err = util.Fetch(template, 3)
+		data, err = util.Fetch(template, 3, userAgent)
 		if err != nil {
 			return "", err
 		}
@@ -320,10 +321,10 @@ func ConvertCProxyToSProxy(proxy string) (model.Outbound, error) {
 	return model.Outbound{}, errors.New("unknown proxy format")
 }
 
-func ConvertSubscriptionsToSProxy(urls []string) ([]model.Outbound, error) {
+func ConvertSubscriptionsToSProxy(urls []string, userAgent string) ([]model.Outbound, error) {
 	proxyList := make([]model.Outbound, 0)
 	for _, url := range urls {
-		data, err := util.Fetch(url, 3)
+		data, err := util.Fetch(url, 3, userAgent)
 		if err != nil {
 			return nil, err
 		}

model/convert.go

@@ -12,4 +12,5 @@ type ConvertRequest struct {
 	SortType      string            `form:"sort-type" json:"sort-type"`
 	Output        string            `json:"output"`
 	GroupRules    string            `form:"group-rules" json:"group-rules"`
+	UserAgent     string            `form:"user-agent" json:"user-agent"`
 }

util/fetch.go

@@ -5,23 +5,31 @@ import (
 	"net/http"
 )
 
-func Fetch(url string, maxRetryTimes int) (string, error) {
+func Fetch(url string, maxRetryTimes int, userAgent string) (string, error) {
 	retryTime := 0
 	var err error
 	var resp *http.Response
 	for retryTime < maxRetryTimes {
-		resp, err = http.Get(url)
+		req, reqErr := http.NewRequest("GET", url, nil)
+		if reqErr != nil {
+			return "", reqErr
+		}
+		if userAgent != "" {
+			req.Header.Set("User-Agent", userAgent)
+		}
+		resp, err = http.DefaultClient.Do(req)
 		if err != nil {
 			retryTime++
 			continue
 		}
 		var data []byte
 		data, err = io.ReadAll(resp.Body)
+		resp.Body.Close()
 		if err != nil {
 			retryTime++
 			continue
 		}
-		return string(data), err
+		return string(data), nil
 	}
 	return "", err
 }