Verify no args are passed to subctl gather

Fixes #1083

Signed-off-by: Tom Pantelis <tompantelis@gmail.com>

cmd/subctl/gather.go

@@ -42,6 +42,7 @@ var gatherCmd = &cobra.Command{
 	Long: fmt.Sprintf("This command gathers information from a submariner cluster for troubleshooting. The information gathered "+
 		"can be selected by component (%v) and type (%v). Default is to capture all data.",
 		strings.Join(gather.AllModules.UnsortedList(), ","), strings.Join(gather.AllTypes.UnsortedList(), ",")),
+	Args: checkNoArguments,
 	Run: func(_ *cobra.Command, _ []string) {
 		if options.Directory == "" {
 			options.Directory = "submariner-" + time.Now().UTC().Format("20060102150405") // submariner-YYYYMMDDHHMMSS

scripts/test/system.sh

@@ -52,6 +52,10 @@ function test_subctl_gather() {
 
     # Broker (on the first cluster)
     with_context "${broker}" validate_broker_resources
+
+    # Should error with an arg passed
+    _subctl gather all && exit 1
+
     echo "::endgroup::"
 }