serve frontend from go

pkg/middlewares/stripprefix.go

@@ -0,0 +1,25 @@
+package middlewares
+
+import (
+	"net/http"
+	"net/url"
+)
+
+func AddPrefix(prefix string, h http.Handler) http.Handler {
+	if prefix == "" {
+		return h
+	}
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		p := prefix + r.URL.Path
+		rp := prefix + r.URL.RawPath
+
+		r2 := new(http.Request)
+		*r2 = *r
+		r2.URL = new(url.URL)
+		*r2.URL = *r.URL
+		r2.URL.Path = p
+		r2.URL.RawPath = rp
+		h.ServeHTTP(w, r2)
+
+	})
+}