terraform: module nodes expand

terraform/graph_builder.go

@@ -13,6 +13,29 @@ type GraphBuilder interface {
 	Build(path []string) (*Graph, error)
 }
 
+// BasicGraphBuilder is a GraphBuilder that builds a graph out of a
+// series of transforms and validates the graph is a valid structure.
+type BasicGraphBuilder struct {
+	Steps []GraphTransformer
+}
+
+// TODO(mitchellh): test
+func (b *BasicGraphBuilder) Build(path []string) (*Graph, error) {
+	g := &Graph{Path: path}
+	for _, step := range b.Steps {
+		if err := step.Transform(g); err != nil {
+			return g, err
+		}
+	}
+
+	// Validate the graph structure
+	if err := g.Validate(); err != nil {
+		return nil, err
+	}
+
+	return g, nil
+}
+
 // BuiltinGraphBuilder is responsible for building the complete graph that
 // Terraform uses for execution. It is an opinionated builder that defines
 // the step order required to build a complete graph as is used and expected
@@ -34,19 +57,11 @@ type BuiltinGraphBuilder struct {
 
 // Build builds the graph according to the steps returned by Steps.
 func (b *BuiltinGraphBuilder) Build(path []string) (*Graph, error) {
-	g := &Graph{Path: path}
-	for _, step := range b.Steps() {
-		if err := step.Transform(g); err != nil {
-			return g, err
-		}
+	basic := &BasicGraphBuilder{
+		Steps: b.Steps(),
 	}
 
-	// Validate the graph structure
-	if err := g.Validate(); err != nil {
-		return nil, err
-	}
-
-	return g, nil
+	return basic.Build(path)
 }
 
 // Steps returns the ordered list of GraphTransformers that must be executed

terraform/graph_config_node.go

@@ -22,6 +22,7 @@ type graphNodeConfig interface {
 
 // GraphNodeConfigModule represents a module within the configuration graph.
 type GraphNodeConfigModule struct {
+	Path   []string
 	Module *config.Module
 	Tree   *module.Tree
 }
@@ -46,6 +47,11 @@ func (n *GraphNodeConfigModule) Name() string {
 	return fmt.Sprintf("module.%s", n.Module.Name)
 }
 
+// GraphNodeExpandable
+func (n *GraphNodeConfigModule) Expand(b GraphBuilder) (*Graph, error) {
+	return b.Build(n.Path)
+}
+
 // GraphNodeConfigProvider represents a configured provider within the
 // configuration graph. These are only immediately in the graph when an
 // explicit `provider` configuration block is in the configuration.

terraform/graph_config_node_test.go

@@ -1,12 +1,45 @@
 package terraform
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/dag"
 )
 
+func TestGraphNodeConfigModule_impl(t *testing.T) {
+	var _ dag.Vertex = new(GraphNodeConfigModule)
+	var _ dag.NamedVertex = new(GraphNodeConfigModule)
+	var _ graphNodeConfig = new(GraphNodeConfigModule)
+	var _ GraphNodeExpandable = new(GraphNodeConfigModule)
+}
+
+func TestGraphNodeConfigModuleExpand(t *testing.T) {
+	mod := testModule(t, "graph-node-module-expand")
+
+	node := &GraphNodeConfigModule{
+		Path:   []string{RootModuleName, "child"},
+		Module: nil,
+		Tree:   nil,
+	}
+
+	g, err := node.Expand(&BasicGraphBuilder{
+		Steps: []GraphTransformer{
+			&ConfigTransformer{Module: mod},
+		},
+	})
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testGraphNodeModuleExpandStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
 func TestGraphNodeConfigProvider_impl(t *testing.T) {
 	var _ dag.Vertex = new(GraphNodeConfigProvider)
 	var _ dag.NamedVertex = new(GraphNodeConfigProvider)
@@ -40,3 +73,9 @@ func TestGraphNodeConfigResource_ProvidedBy(t *testing.T) {
 		t.Fatalf("bad: %#v", v)
 	}
 }
+
+const testGraphNodeModuleExpandStr = `
+aws_instance.bar
+  aws_instance.foo
+aws_instance.foo
+`

terraform/test-fixtures/graph-node-module-expand/child/main.tf

@@ -0,0 +1,4 @@
+resource "aws_instance" "foo" {}
+resource "aws_instance" "bar" {
+    var = "${aws_instance.foo.whatever}"
+}

terraform/test-fixtures/graph-node-module-expand/main.tf

@@ -0,0 +1,3 @@
+module "child" {
+    source = "./child"
+}

terraform/transform_config.go

@@ -53,7 +53,12 @@ func (t *ConfigTransformer) Transform(g *Graph) error {
 	// Write all the modules out
 	children := module.Children()
 	for _, m := range config.Modules {
+		path := make([]string, len(g.Path), len(g.Path)+1)
+		copy(path, g.Path)
+		path = append(path, m.Name)
+
 		nodes = append(nodes, &GraphNodeConfigModule{
+			Path:   path,
 			Module: m,
 			Tree:   children[m.Name],
 		})