Better handling on platforms where os/user.Current() is not implemented (#294)

Signed-off-by: David Chung <[email protected]>

Author: David Chung

discovery/discovery.go

@@ -26,17 +26,20 @@ func Dir() string {
 		return pluginDir
 	}
 
-	usr, err := user.Current()
-	if err != nil {
-		panic(err)
+	home := os.Getenv("HOME")
+	if usr, err := user.Current(); err == nil {
+		home = usr.HomeDir
 	}
-	return path.Join(usr.HomeDir, ".infrakit/plugins")
+	return path.Join(home, ".infrakit/plugins")
 }
 
 // NewPluginDiscovery creates a plugin discovery based on the environment configuration.
 func NewPluginDiscovery() (Plugins, error) {
-	pluginDir := Dir()
+	return NewPluginDiscoveryWithDirectory(Dir())
+}
 
+// NewPluginDiscoveryWithDirectory creates a plugin discovery based on the directory given.
+func NewPluginDiscoveryWithDirectory(pluginDir string) (Plugins, error) {
 	stat, err := os.Stat(pluginDir)
 	if err == nil {
 		if !stat.IsDir() {

plugin/flavor/swarm/flavor.go

@@ -50,14 +50,14 @@ func validateIDsAndAttachments(logicalIDs []instance.LogicalID, attachments map[
 	idsMap := map[instance.LogicalID]bool{}
 	for _, id := range logicalIDs {
 		if _, exists := idsMap[id]; exists {
-			return fmt.Errorf("LogicalID %s specified more than once", id)
+			return fmt.Errorf("LogicalID %v specified more than once", id)
 		}
 
 		idsMap[id] = true
 	}
 	for id := range attachments {
 		if _, exists := idsMap[id]; !exists {
-			return fmt.Errorf("LogicalID %s used for an attachment but is not in group LogicalIDs", id)
+			return fmt.Errorf("LogicalID %v used for an attachment but is not in group LogicalIDs", id)
 		}
 	}
 
@@ -66,7 +66,7 @@ func validateIDsAndAttachments(logicalIDs []instance.LogicalID, attachments map[
 	for _, att := range attachments {
 		for _, attachment := range att {
 			if _, exists := allAttachments[attachment]; exists {
-				return fmt.Errorf("Attachment %s specified more than once", attachment)
+				return fmt.Errorf("Attachment %v specified more than once", attachment)
 			}
 			allAttachments[attachment] = true
 		}