Set default header for User-Agent

http.go

@@ -0,0 +1,14 @@
+package main
+
+import "net/http"
+
+// httpClient is a wrapper around the default http.Client
+// It is used to add default headers to the requests.
+type httpClient struct {
+	*http.Client
+}
+
+func (c *httpClient) Do(req *http.Request) (*http.Response, error) {
+	req.Header.Set("User-Agent", "ntfy-alertmanger")
+	return c.Client.Do(req)
+}

main.go

@@ -25,7 +25,7 @@ type receiver struct {
 	cfg    *config
 	logger *log.Logger
 	cache  *cache
-	client *http.Client
+	client *httpClient
 }
 
 type payload struct {
@@ -391,7 +391,7 @@ func main() {
 		logger.Errorf("config: %v", err)
 	}
 
-	client := &http.Client{Timeout: time.Second * 3}
+	client := &httpClient{&http.Client{Timeout: time.Second * 3}}
 
 	receiver := &receiver{cfg: cfg, logger: logger, cache: newCache(cfg.cache.Duration), client: client}