From bd8802e08d87d24c828cc0412bb86b37c7768aa2 Mon Sep 17 00:00:00 2001
From: Mitchell Hashimoto <mitchell.hashimoto@gmail.com>
Date: Mon, 7 Nov 2016 08:57:27 -0800
Subject: [PATCH] terraform: plan orphan destruction

---
 terraform/graph_builder_plan.go        | 13 ++++++
 terraform/node_resource_plan_orphan.go | 59 ++++++++++++++++++++++++++
 2 files changed, 72 insertions(+)
 create mode 100644 terraform/node_resource_plan_orphan.go

diff --git a/terraform/graph_builder_plan.go b/terraform/graph_builder_plan.go
index e25749299..f38828f0c 100644
--- a/terraform/graph_builder_plan.go
+++ b/terraform/graph_builder_plan.go
@@ -55,6 +55,12 @@ func (b *PlanGraphBuilder) Steps() []GraphTransformer {
 		}
 	}
 
+	concreteResourceOrphan := func(a *NodeAbstractResource) dag.Vertex {
+		return &NodePlannableResourceOrphan{
+			NodeAbstractResource: a,
+		}
+	}
+
 	steps := []GraphTransformer{
 		// Creates all the resources represented in the config
 		&ConfigTransformer{
@@ -65,6 +71,13 @@ func (b *PlanGraphBuilder) Steps() []GraphTransformer {
 		// Add the outputs
 		&OutputTransformer{Module: b.Module},
 
+		// Add orphan resources
+		&OrphanResourceTransformer{
+			Concrete: concreteResourceOrphan,
+			State:    b.State,
+			Module:   b.Module,
+		},
+
 		// Attach the configuration to any resources
 		&AttachResourceConfigTransformer{Module: b.Module},
 
diff --git a/terraform/node_resource_plan_orphan.go b/terraform/node_resource_plan_orphan.go
new file mode 100644
index 000000000..e8d700bde
--- /dev/null
+++ b/terraform/node_resource_plan_orphan.go
@@ -0,0 +1,59 @@
+package terraform
+
+import (
+	"fmt"
+)
+
+// NodePlannableResourceOrphan represents a resource that is "applyable":
+// it is ready to be applied and is represented by a diff.
+type NodePlannableResourceOrphan struct {
+	*NodeAbstractResource
+}
+
+func (n *NodePlannableResourceOrphan) Name() string {
+	return n.NodeAbstractResource.Name() + " (orphan)"
+}
+
+// GraphNodeEvalable
+func (n *NodePlannableResourceOrphan) EvalTree() EvalNode {
+	addr := n.NodeAbstractResource.Addr
+
+	// stateId is the ID to put into the state
+	stateId := addr.stateId()
+	if addr.Index > -1 {
+		stateId = fmt.Sprintf("%s.%d", stateId, addr.Index)
+	}
+
+	// Build the instance info. More of this will be populated during eval
+	info := &InstanceInfo{
+		Id:   stateId,
+		Type: addr.Type,
+	}
+
+	// Declare a bunch of variables that are used for state during
+	// evaluation. Most of this are written to by-address below.
+	var diff *InstanceDiff
+	var state *InstanceState
+
+	return &EvalSequence{
+		Nodes: []EvalNode{
+			&EvalReadState{
+				Name:   stateId,
+				Output: &state,
+			},
+			&EvalDiffDestroy{
+				Info:   info,
+				State:  &state,
+				Output: &diff,
+			},
+			&EvalCheckPreventDestroy{
+				Resource: n.Config,
+				Diff:     &diff,
+			},
+			&EvalWriteDiff{
+				Name: stateId,
+				Diff: &diff,
+			},
+		},
+	}
+}