cmd/*: fail on unrecognized flags/arguments for component CLI

In case a malformed flag is passed to k8s components
such as "–foo", where "–" is not an ASCII dash character,
the components currently silently ignore the flag
and treat it as a positional argument.

Make k8s components/commands exit with an error if a positional argument
that is not empty is found. Include a custom error message for all
components except kubeadm, as cobra.NoArgs is used in a lot of
places already (can be fixed in a followup).

The kubelet already handles this properly - e.g.:
'unknown command: "–foo"'

This change affects:
- cloud-controller-manager
- kube-apiserver
- kube-controller-manager
- kube-proxy
- kubeadm {alpha|config|token|version}
- kubemark

Signed-off-by: Monis Khan <mok@vmware.com>
Signed-off-by: Lubomir I. Ivanov <lubomirivanov@vmware.com>

cmd/kube-controller-manager/app/controllermanager.go

@@ -119,6 +119,14 @@ controller, and serviceaccounts controller.`,
 				os.Exit(1)
 			}
 		},
+		Args: func(cmd *cobra.Command, args []string) error {
+			for _, arg := range args {
+				if len(arg) > 0 {
+					return fmt.Errorf("%q does not take any arguments, got %q", cmd.CommandPath(), args)
+				}
+			}
+			return nil
+		},
 	}
 
 	fs := cmd.Flags()