command: put the modules in ".terraform/modules"

This also fixes a case where tests wre leaking files

command/command.go

@@ -19,6 +19,10 @@ const DefaultVarsFilename = "terraform.tfvars"
 // DefaultBackupExtention is added to the state file to form the path
 const DefaultBackupExtention = ".backup"
 
+// DefaultDataDirectory is the directory where local state is stored
+// by default.
+const DefaultDataDirectory = ".terraform"
+
 func validateContext(ctx *terraform.Context, ui cli.Ui) bool {
 	if ws, es := ctx.Validate(); len(ws) > 0 || len(es) > 0 {
 		ui.Output(

command/get_test.go

@@ -14,6 +14,7 @@ func TestGet(t *testing.T) {
 		Meta: Meta{
 			ContextOpts: testCtxConfig(testProvider()),
 			Ui:          ui,
+			dataDir:     tempDir(t),
 		},
 	}
 
@@ -39,6 +40,7 @@ func TestGet_multipleArgs(t *testing.T) {
 		Meta: Meta{
 			ContextOpts: testCtxConfig(testProvider()),
 			Ui:          ui,
+			dataDir:     tempDir(t),
 		},
 	}
 
@@ -66,6 +68,7 @@ func TestGet_noArgs(t *testing.T) {
 		Meta: Meta{
 			ContextOpts: testCtxConfig(testProvider()),
 			Ui:          ui,
+			dataDir:     tempDir(t),
 		},
 	}
 
@@ -89,6 +92,7 @@ func TestGet_update(t *testing.T) {
 		Meta: Meta{
 			ContextOpts: testCtxConfig(testProvider()),
 			Ui:          ui,
+			dataDir:     tempDir(t),
 		},
 	}
 

command/meta.go

@@ -27,6 +27,9 @@ type Meta struct {
 	// This can be set by the command itself to provide extra hooks.
 	extraHooks []terraform.Hook
 
+	// This can be set by tests to change some directories
+	dataDir string
+
 	// Variables for the context (private)
 	autoKey       string
 	autoVariables map[string]string
@@ -95,7 +98,12 @@ func (m *Meta) Context(copts contextOpts) (*terraform.Context, bool, error) {
 	if err != nil {
 		return nil, false, fmt.Errorf("Error loading config: %s", err)
 	}
-	err = mod.Load(m.moduleStorage(copts.Path), copts.GetMode)
+
+	dataDir := DefaultDataDirectory
+	if m.dataDir != "" {
+		dataDir = m.dataDir
+	}
+	err = mod.Load(m.moduleStorage(dataDir), copts.GetMode)
 	if err != nil {
 		return nil, false, fmt.Errorf("Error downloading modules: %s", err)
 	}