pkg/types: Support Unix sockets in NewURLS

Resolves #12450
This commits adds support to unix/unixs socket URLs, which currently
fail with the message "URL address does not have the form "host:port".
It also replaces the work started in #11747.

client/pkg/types/urls.go

@@ -36,20 +36,25 @@ func NewURLs(strs []string) (URLs, error) {
 		if err != nil {
 			return nil, err
 		}
-		if u.Scheme != "http" && u.Scheme != "https" && u.Scheme != "unix" && u.Scheme != "unixs" {
+
+		switch u.Scheme {
+		case "http", "https":
+			if _, _, err := net.SplitHostPort(u.Host); err != nil {
+				return nil, fmt.Errorf(`URL address does not have the form "host:port": %s`, in)
+			}
+
+			if u.Path != "" {
+				return nil, fmt.Errorf("URL must not contain a path: %s", in)
+			}
+		case "unix", "unixs":
+			break
+		default:
 			return nil, fmt.Errorf("URL scheme must be http, https, unix, or unixs: %s", in)
 		}
-		if _, _, err := net.SplitHostPort(u.Host); err != nil {
-			return nil, fmt.Errorf(`URL address does not have the form "host:port": %s`, in)
-		}
-		if u.Path != "" {
-			return nil, fmt.Errorf("URL must not contain a path: %s", in)
-		}
 		all[i] = *u
 	}
 	us := URLs(all)
 	us.Sort()
-
 	return us, nil
 }
 

pkg/flags/urls_test.go

@@ -29,9 +29,6 @@ func TestValidateURLsValueBad(t *testing.T) {
 		// bad port specification
 		"127.0.0.1:foo",
 		"127.0.0.1:",
-		// unix sockets not supported
-		"unix://",
-		"unix://tmp/etcd.sock",
 		// bad strings
 		"somewhere",
 		"234#$",