Command-line input validation: reject unused args

Several podman commands accept no subcommands. Some
of those were not actually checking, though, which
could lead to user confusion. Added validation where
missing; and, refactored to minimize duplication.

(Side note: I decided against using cobra.NoArgs
because its error message, "unknown command",
misleadingly implies that there are known ones).

Also added validation to varlink

Signed-off-by: Ed Santiago <santiago@redhat.com>

1 files changed, 1 insertions, 4 deletions

diff --git a/cmd/podman/volume_ls.go b/cmd/podman/volume_ls.go
index 5adfc1e91..6855f38e0 100644
--- a/cmd/podman/volume_ls.go
+++ b/cmd/podman/volume_ls.go
@@ -49,6 +49,7 @@ and the output format can be changed to JSON or a user specified Go template.
 	_volumeLsCommand = &cobra.Command{
 		Use:     "ls",
 		Aliases: []string{"list"},
+		Args:    noSubArgs,
 		Short:   "List volumes",
 		Long:    volumeLsDescription,
 		RunE: func(cmd *cobra.Command, args []string) error {
@@ -76,10 +77,6 @@ func volumeLsCmd(c *cliconfig.VolumeLsValues) error {
 	}
 	defer runtime.Shutdown(false)
 
-	if len(c.InputArgs) > 0 {
-		return errors.Errorf("too many arguments, ls takes no arguments")
-	}
-
 	opts := volumeLsOptions{
 		Quiet: c.Quiet,
 	}