terraform: RootVariableTransform

terraform/graph_builder_apply.go

@@ -63,6 +63,9 @@ func (b *ApplyGraphBuilder) Steps() []GraphTransformer {
 		&MissingProvisionerTransformer{Provisioners: b.Provisioners},
 		&ProvisionerTransformer{},
 
+		// Add root variables
+		&RootVariableTransformer{Module: b.Module},
+
 		// Add module variables
 		&ModuleVariableTransformer{Module: b.Module},
 

terraform/node_root_variable.go

@@ -0,0 +1,22 @@
+package terraform
+
+import (
+	"fmt"
+
+	"github.com/hashicorp/terraform/config"
+)
+
+// NodeRootVariable represents a root variable input.
+type NodeRootVariable struct {
+	Config *config.Variable
+}
+
+func (n *NodeRootVariable) Name() string {
+	result := fmt.Sprintf("var.%s", n.Config.Name)
+	return result
+}
+
+// GraphNodeReferenceable
+func (n *NodeRootVariable) ReferenceableName() []string {
+	return []string{n.Name()}
+}

terraform/transform_variable.go

@@ -0,0 +1,40 @@
+package terraform
+
+import (
+	"github.com/hashicorp/terraform/config/module"
+)
+
+// RootVariableTransformer is a GraphTransformer that adds all the root
+// variables to the graph.
+//
+// Root variables are currently no-ops but they must be added to the
+// graph since downstream things that depend on them must be able to
+// reach them.
+type RootVariableTransformer struct {
+	Module *module.Tree
+}
+
+func (t *RootVariableTransformer) Transform(g *Graph) error {
+	// If no config, no variables
+	if t.Module == nil {
+		return nil
+	}
+
+	// If we have no vars, we're done!
+	vars := t.Module.Config().Variables
+	if len(vars) == 0 {
+		return nil
+	}
+
+	// Add all variables here
+	for _, v := range vars {
+		node := &NodeRootVariable{
+			Config: v,
+		}
+
+		// Add it!
+		g.Add(node)
+	}
+
+	return nil
+}