Add hostname check in registry URL on login

Signed-off-by: Vlad Cherkasov <[email protected]>

cli/command/registry/login.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"net/url"
 	"strings"
 
 	"github.com/docker/cli/cli"
@@ -97,6 +98,16 @@ func verifyloginOptions(dockerCli command.Cli, opts *loginOptions) error {
 		opts.password = strings.TrimSuffix(string(contents), "\n")
 		opts.password = strings.TrimSuffix(opts.password, "\r")
 	}
+
+	if opts.serverAddress != "" {
+		u, err := url.Parse(opts.serverAddress)
+		if err != nil {
+			return errors.Errorf("Invalid server address: %s", opts.serverAddress)
+		}
+		if u.Host == "" {
+			return errors.Errorf("Server address must include a hostname: %s", opts.serverAddress)
+		}
+	}
 	return nil
 }