fix crash with new args method when minimega not running

src/go/util/mm/file.go

@@ -29,7 +29,13 @@ func GetMMFullPath(path string) string {
 func GetMMFilesDirectory() string {
 	defaultMMFilesDirectory := fmt.Sprintf("%s/images", common.PhenixBase)
 
-	path, ok := GetMMArgs()["filepath"]
+	args, err := GetMMArgs()
+	if err != nil {
+		plog.Warn("Could not get mm files directory from minimega")
+		return defaultMMFilesDirectory
+	}
+
+	path, ok := args["filepath"]
 	if !ok {
 		plog.Warn("Could not get mm files directory from minimega")
 		return defaultMMFilesDirectory

src/go/util/mm/minimega.go

@@ -816,10 +816,14 @@ func (this Minimega) IsHeadnode(node string) bool {
 	return node == this.Headnode()
 }
 
-func (this Minimega) GetMMArgs() map[string]string {
+func (this Minimega) GetMMArgs() (map[string]string, error) {
 	cmd := mmcli.NewCommand()
 	cmd.Command = "args"
-	return mmcli.RunTabular(cmd)[0]
+	rows := mmcli.RunTabular(cmd)
+	if len(rows) == 1 {
+		return rows[0], nil
+	}
+	return nil, fmt.Errorf("no args returned")
 }
 
 func (Minimega) GetVLANs(opts ...Option) (map[string]int, error) {

src/go/util/mm/mm.go

@@ -37,7 +37,7 @@ type MM interface {
 	GetNamespaceHosts(string) (Hosts, error)
 	Headnode() string
 	IsHeadnode(string) bool
-	GetMMArgs() map[string]string
+	GetMMArgs() (map[string]string, error)
 	GetVLANs(...Option) (map[string]int, error)
 
 	IsC2ClientActive(...C2Option) error

src/go/util/mm/package.go

@@ -108,7 +108,7 @@ func IsHeadnode(node string) bool {
 	return DefaultMM.IsHeadnode(node)
 }
 
-func GetMMArgs() map[string]string {
+func GetMMArgs() (map[string]string, error) {
 	return DefaultMM.GetMMArgs()
 }