Add UserAgent

default.go

@@ -64,10 +64,21 @@ func (api *LinkInfoApi) DefaultLinkHandler(link string) (*LinkInfo, error) {
 		return nil, errors.New("url is a local ip address")
 	}
 
+	var req *http.Request
 	var res *http.Response
 
 	for i := 0; i < 10; i++ {
-		res, err = api.Client.Head(link)
+		req, err = http.NewRequest(http.MethodHead, link, nil)
+
+		if err != nil {
+			return nil, err
+		}
+
+		if api.UserAgent != "" {
+			req.Header.Set("User-Agent", api.UserAgent)
+		}
+
+		res, err = api.Client.Do(req)
 
 		if err != nil {
 			return nil, err
@@ -140,6 +151,10 @@ func (api *LinkInfoApi) detectContentType(link, defaultType string) string {
 		return defaultType
 	}
 
+	if api.UserAgent != "" {
+		req.Header.Set("User-Agent", api.UserAgent)
+	}
+
 	req.Header.Set("Range", "bytes=0-512")
 
 	res, err := api.Client.Do(req)
@@ -170,7 +185,17 @@ var (
 )
 
 func (api *LinkInfoApi) retrieveHtmlLinkTitle(i *LinkInfo, link string) error {
-	res, err := api.Client.Get(link)
+	req, err := http.NewRequest(http.MethodGet, link, nil)
+
+	if err != nil {
+		return err
+	}
+
+	if api.UserAgent != "" {
+		req.Header.Set("User-Agent", api.UserAgent)
+	}
+
+	res, err := api.Client.Do(req)
 
 	if err != nil {
 		return err

linkinfo.go

@@ -13,6 +13,7 @@ type LinkHandler struct {
 
 type LinkInfoApi struct {
 	Client    *http.Client
+	UserAgent string
 
 	Imgur        *ImgurInfoApi
 	Youtube      *YoutubeInfoApi
@@ -29,22 +30,30 @@ type LinkInfo struct {
 	Redirects     []string `json:"redirects,omitempty"`
 }
 
+type HttpOptions struct {
+	Option
+
+	UserAgent string
+}
+
 func New(opts ...Option) *LinkInfoApi {
 	api := &LinkInfoApi{
 		Client: &http.Client{
-			Timeout: 60 * time.Second,
+			Timeout: 15 * time.Second,
 		},
 	}
 
 	for _, opt := range opts {
-		switch opt.(type) {
+		switch o := opt.(type) {
 		case *ImgurOptions:
-			api.Imgur = &ImgurInfoApi{api, opt.(*ImgurOptions)}
+			api.Imgur = &ImgurInfoApi{api, o}
 		case *YoutubeOptions:
-			api.Youtube = &YoutubeInfoApi{api, opt.(*YoutubeOptions)}
+			api.Youtube = &YoutubeInfoApi{api, o}
 		case *TwitterOptions:
-			api.Twitter = &TwitterInfoApi{opts: opt.(*TwitterOptions)}
+			api.Twitter = &TwitterInfoApi{opts: o}
 			api.Twitter.Init()
+		case *HttpOptions:
+			api.UserAgent = o.UserAgent
 		}
 	}
 

service/main.go

@@ -60,6 +60,10 @@ func main() {
 		})
 	}
 
+	opts = append(opts, &linkinfo.HttpOptions{
+		UserAgent: "LinkInfo/1.0",
+	})
+
 	api = linkinfo.New(opts...)
 
 	var err error