terraform: add destroy nodes, destroys kind of work

terraform/graph_builder_apply.go

@@ -54,6 +54,9 @@ func (b *ApplyGraphBuilder) Steps() []GraphTransformer {
 			State:  b.State,
 		},
 
+		// Attach the state
+		&AttachStateTransformer{State: b.State},
+
 		// Create all the providers
 		&MissingProviderTransformer{Providers: b.Providers, Factory: providerFactory},
 		&ProviderTransformer{},

terraform/node_resource_apply.go

@@ -86,6 +86,16 @@ func (n *NodeApplyableResource) ProvisionedBy() []string {
 	return result
 }
 
+// GraphNodeAttachResourceState
+func (n *NodeApplyableResource) ResourceAddr() *ResourceAddress {
+	return n.Addr
+}
+
+// GraphNodeAttachResourceState
+func (n *NodeApplyableResource) AttachResourceState(s *ResourceState) {
+	n.ResourceState = s
+}
+
 // GraphNodeEvalable
 func (n *NodeApplyableResource) EvalTree() EvalNode {
 	// stateId is the ID to put into the state

terraform/node_resource_destroy.go

@@ -2,50 +2,152 @@ package terraform
 
 import (
 	"fmt"
-
-	"github.com/hashicorp/terraform/config"
 )
 
 // NodeDestroyResource represents a resource that is to be destroyed.
-type NodeApplyableResource struct {
-	Addr *ResourceAddress // Addr is the address for this resource
+type NodeDestroyResource struct {
+	Addr          *ResourceAddress // Addr is the address for this resource
+	ResourceState *ResourceState   // State is the resource state for this resource
 }
 
-func (n *NodeApplyableResource) Name() string {
+func (n *NodeDestroyResource) Name() string {
 	return n.Addr.String()
 }
 
 // GraphNodeSubPath
-func (n *NodeApplyableResource) Path() []string {
+func (n *NodeDestroyResource) Path() []string {
 	return n.Addr.Path
 }
 
-// GraphNodeReferenceable
-func (n *NodeApplyableResource) ReferenceableName() []string {
-	if n.Config == nil {
-		return nil
-	}
-
-	return []string{n.Config.Id()}
-}
-
 // GraphNodeProviderConsumer
-func (n *NodeApplyableResource) ProvidedBy() []string {
-	// If we have a config we prefer that above all else
-	if n.Config != nil {
-		return []string{resourceProvider(n.Config.Type, n.Config.Provider)}
-	}
-
+func (n *NodeDestroyResource) ProvidedBy() []string {
 	// If we have state, then we will use the provider from there
-	if n.ResourceState != nil {
+	if n.ResourceState != nil && n.ResourceState.Provider != "" {
 		return []string{n.ResourceState.Provider}
 	}
 
 	// Use our type
 	return []string{resourceProvider(n.Addr.Type, "")}
 }
 
+// GraphNodeAttachResourceState
+func (n *NodeDestroyResource) ResourceAddr() *ResourceAddress {
+	return n.Addr
+}
+
+// GraphNodeAttachResourceState
+func (n *NodeDestroyResource) AttachResourceState(s *ResourceState) {
+	n.ResourceState = s
+}
+
 // GraphNodeEvalable
-func (n *NodeApplyableResource) EvalTree() EvalNode {
-	return nil
+func (n *NodeDestroyResource) EvalTree() EvalNode {
+	// stateId is the ID to put into the state
+	stateId := n.Addr.stateId()
+	if n.Addr.Index > -1 {
+		stateId = fmt.Sprintf("%s.%d", stateId, n.Addr.Index)
+	}
+
+	// Build the instance info. More of this will be populated during eval
+	info := &InstanceInfo{
+		Id:   stateId,
+		Type: n.Addr.Type,
+	}
+
+	// Get our state
+	rs := n.ResourceState
+	if rs == nil {
+		rs = &ResourceState{}
+	}
+	rs.Provider = n.ProvidedBy()[0]
+
+	var diffApply *InstanceDiff
+	var provider ResourceProvider
+	var state *InstanceState
+	var err error
+	return &EvalOpFilter{
+		Ops: []walkOperation{walkApply, walkDestroy},
+		Node: &EvalSequence{
+			Nodes: []EvalNode{
+				// Get the saved diff for apply
+				&EvalReadDiff{
+					Name: stateId,
+					Diff: &diffApply,
+				},
+
+				// Filter the diff so we only get the destroy
+				&EvalFilterDiff{
+					Diff:    &diffApply,
+					Output:  &diffApply,
+					Destroy: true,
+				},
+
+				// If we're not destroying, then compare diffs
+				&EvalIf{
+					If: func(ctx EvalContext) (bool, error) {
+						if diffApply != nil && diffApply.GetDestroy() {
+							return true, nil
+						}
+
+						return true, EvalEarlyExitError{}
+					},
+					Then: EvalNoop{},
+				},
+
+				// Load the instance info so we have the module path set
+				&EvalInstanceInfo{Info: info},
+
+				&EvalGetProvider{
+					Name:   n.ProvidedBy()[0],
+					Output: &provider,
+				},
+				&EvalReadState{
+					Name:   stateId,
+					Output: &state,
+				},
+				&EvalRequireState{
+					State: &state,
+				},
+				// Make sure we handle data sources properly.
+				&EvalIf{
+					If: func(ctx EvalContext) (bool, error) {
+						/* TODO: data source
+						if n.Resource.Mode == config.DataResourceMode {
+							return true, nil
+						}
+						*/
+
+						return false, nil
+					},
+
+					Then: &EvalReadDataApply{
+						Info:     info,
+						Diff:     &diffApply,
+						Provider: &provider,
+						Output:   &state,
+					},
+					Else: &EvalApply{
+						Info:     info,
+						State:    &state,
+						Diff:     &diffApply,
+						Provider: &provider,
+						Output:   &state,
+						Error:    &err,
+					},
+				},
+				&EvalWriteState{
+					Name:         stateId,
+					ResourceType: n.Addr.Type,
+					Provider:     rs.Provider,
+					Dependencies: rs.Dependencies,
+					State:        &state,
+				},
+				&EvalApplyPost{
+					Info:  info,
+					State: &state,
+					Error: &err,
+				},
+			},
+		},
+	}
 }

terraform/transform_attach_state.go

@@ -0,0 +1,68 @@
+package terraform
+
+import (
+	"log"
+
+	"github.com/hashicorp/terraform/dag"
+)
+
+// GraphNodeAttachResourceState is an interface that can be implemented
+// to request that a ResourceState is attached to the node.
+type GraphNodeAttachResourceState interface {
+	// The address to the resource for the state
+	ResourceAddr() *ResourceAddress
+
+	// Sets the state
+	AttachResourceState(*ResourceState)
+}
+
+// AttachStateTransformer goes through the graph and attaches
+// state to nodes that implement the interfaces above.
+type AttachStateTransformer struct {
+	State *State // State is the root state
+}
+
+func (t *AttachStateTransformer) Transform(g *Graph) error {
+	// If no state, then nothing to do
+	if t.State == nil {
+		log.Printf("[DEBUG] Not attaching any state: state is nil")
+		return nil
+	}
+
+	filter := &StateFilter{State: t.State}
+	for _, v := range g.Vertices() {
+		// Only care about nodes requesting we're adding state
+		an, ok := v.(GraphNodeAttachResourceState)
+		if !ok {
+			continue
+		}
+		addr := an.ResourceAddr()
+
+		// Get the module state
+		results, err := filter.Filter(addr.String())
+		if err != nil {
+			return err
+		}
+
+		// Attach the first resource state we get
+		found := false
+		for _, result := range results {
+			if rs, ok := result.Value.(*ResourceState); ok {
+				log.Printf(
+					"[DEBUG] Attaching resource state to %q: %s",
+					dag.VertexName(v), rs)
+				an.AttachResourceState(rs)
+				found = true
+				break
+			}
+		}
+
+		if !found {
+			log.Printf(
+				"[DEBUG] Resource state not foudn for %q: %s",
+				dag.VertexName(v), addr)
+		}
+	}
+
+	return nil
+}

terraform/transform_diff.go

@@ -41,16 +41,6 @@ func (t *DiffTransformer) Transform(g *Graph) error {
 		for name, inst := range m.Resources {
 			log.Printf("[TRACE] DiffTransformer: Resource %q: %#v", name, inst)
 
-			// TODO: destroy
-			if inst.Destroy {
-			}
-
-			// If this diff has no attribute changes, then we have
-			// nothing to do and therefore won't add it to the graph.
-			if len(inst.Attributes) == 0 {
-				continue
-			}
-
 			// We have changes! This is a create or update operation.
 			// First grab the address so we have a unique way to
 			// reference this resource.
@@ -64,10 +54,18 @@ func (t *DiffTransformer) Transform(g *Graph) error {
 			// the address. Remove "root" from it.
 			addr.Path = m.Path[1:]
 
-			// Add the resource to the graph
-			nodes = append(nodes, &NodeApplyableResource{
-				Addr: addr,
-			})
+			// If we're destroying, add the destroy node
+			if inst.Destroy {
+				g.Add(&NodeDestroyResource{Addr: addr})
+			}
+
+			// If we have changes, then add the applyable version
+			if len(inst.Attributes) > 0 {
+				// Add the resource to the graph
+				nodes = append(nodes, &NodeApplyableResource{
+					Addr: addr,
+				})
+			}
 		}
 	}
 
@@ -97,28 +95,6 @@ func (t *DiffTransformer) Transform(g *Graph) error {
 				break
 			}
 		}
-
-		// Grab the state at this path
-		if ms := t.State.ModuleByPath(normalizeModulePath(n.Addr.Path)); ms != nil {
-			for name, rs := range ms.Resources {
-				// Parse the name for comparison
-				addr, err := parseResourceAddressInternal(name)
-				if err != nil {
-					panic(fmt.Sprintf(
-						"Error parsing internal name, this is a bug: %q", name))
-				}
-				addr.Path = n.Addr.Path
-
-				// If this is not the same resource, then continue
-				if !addr.Equals(n.Addr) {
-					continue
-				}
-
-				// Same resource!
-				n.ResourceState = rs
-				break
-			}
-		}
 	}
 
 	// Add all the nodes to the graph