additional validation of user-provided URLs

quesma/quesma/config/url.go

@@ -2,7 +2,10 @@
 // SPDX-License-Identifier: Elastic-2.0
 package config
 
-import "net/url"
+import (
+	"fmt"
+	"net/url"
+)
 
 type Url url.URL
 
@@ -15,6 +18,12 @@ func (u *Url) UnmarshalText(text []byte) error {
 	if err != nil {
 		return err
 	}
+	if len(urlValue.Scheme) == 0 {
+		return fmt.Errorf("URL scheme (e.g. http:// or clickhouse://) is missing from the provided URL: %s", urlValue)
+	}
+	if len(urlValue.Port()) == 0 {
+		return fmt.Errorf("URL port (e.g. 8123 in 'http://localhost:8123') is missing from the provided URL: %s", urlValue)
+	}
 	*u = Url(*urlValue)
 	return nil
 }