terraform: connect providers in the apply graph

terraform/graph.go

@@ -28,6 +28,11 @@ type Graph struct {
 	// RootModuleName
 	Path []string
 
+	// annotations are the annotations that are added to vertices. Annotations
+	// are arbitrary metadata taht is used for various logic. Annotations
+	// should have unique keys that are referenced via constants.
+	annotations map[dag.Vertex]map[string]interface{}
+
 	// dependableMap is a lookaside table for fast lookups for connecting
 	// dependencies by their GraphNodeDependable value to avoid O(n^3)-like
 	// situations and turn them into O(1) with respect to the number of new
@@ -37,6 +42,29 @@ type Graph struct {
 	once sync.Once
 }
 
+// Annotations returns the annotations that are configured for the
+// given vertex. The map is guaranteed to be non-nil but may be empty.
+//
+// The returned map may be modified to modify the annotations of the
+// vertex.
+func (g *Graph) Annotations(v dag.Vertex) map[string]interface{} {
+	g.once.Do(g.init)
+
+	// If this vertex isn't in the graph, then just return an empty map
+	if !g.HasVertex(v) {
+		return map[string]interface{}{}
+	}
+
+	// Get the map, if it doesn't exist yet then initialize it
+	m, ok := g.annotations[v]
+	if !ok {
+		m = make(map[string]interface{})
+		g.annotations[v] = m
+	}
+
+	return m
+}
+
 // Add is the same as dag.Graph.Add.
 func (g *Graph) Add(v dag.Vertex) dag.Vertex {
 	g.once.Do(g.init)
@@ -51,6 +79,14 @@ func (g *Graph) Add(v dag.Vertex) dag.Vertex {
 		}
 	}
 
+	// If this initializes annotations, then do that
+	if av, ok := v.(GraphNodeAnnotationInit); ok {
+		as := g.Annotations(v)
+		for k, v := range av.AnnotationInit() {
+			as[k] = v
+		}
+	}
+
 	return v
 }
 
@@ -65,12 +101,17 @@ func (g *Graph) Remove(v dag.Vertex) dag.Vertex {
 		}
 	}
 
+	// Remove the annotations
+	delete(g.annotations, v)
+
 	// Call upwards to remove it from the actual graph
 	return g.Graph.Remove(v)
 }
 
 // Replace is the same as dag.Graph.Replace
 func (g *Graph) Replace(o, n dag.Vertex) bool {
+	g.once.Do(g.init)
+
 	// Go through and update our lookaside to point to the new vertex
 	for k, v := range g.dependableMap {
 		if v == o {
@@ -82,6 +123,12 @@ func (g *Graph) Replace(o, n dag.Vertex) bool {
 		}
 	}
 
+	// Move the annotation if it exists
+	if m, ok := g.annotations[o]; ok {
+		g.annotations[n] = m
+		delete(g.annotations, o)
+	}
+
 	return g.Graph.Replace(o, n)
 }
 
@@ -153,6 +200,10 @@ func (g *Graph) Walk(walker GraphWalker) error {
 }
 
 func (g *Graph) init() {
+	if g.annotations == nil {
+		g.annotations = make(map[dag.Vertex]map[string]interface{})
+	}
+
 	if g.dependableMap == nil {
 		g.dependableMap = make(map[string]dag.Vertex)
 	}
@@ -237,6 +288,16 @@ func (g *Graph) walk(walker GraphWalker) error {
 	return g.AcyclicGraph.Walk(walkFn)
 }
 
+// GraphNodeAnnotationInit is an interface that allows a node to
+// initialize it's annotations.
+//
+// AnnotationInit will be called _once_ when the node is added to a
+// graph for the first time and is expected to return it's initial
+// annotations.
+type GraphNodeAnnotationInit interface {
+	AnnotationInit() map[string]interface{}
+}
+
 // GraphNodeDependable is an interface which says that a node can be
 // depended on (an edge can be placed between this node and another) according
 // to the well-known name returned by DependableName.

terraform/graph_builder_apply.go

@@ -39,6 +39,10 @@ func (b *ApplyGraphBuilder) Steps() []GraphTransformer {
 		// Creates all the nodes represented in the diff.
 		&DiffTransformer{Diff: b.Diff},
 
+		// Create all the providers
+		&MissingProviderTransformer{Providers: b.Providers},
+		&ProviderTransformer{},
+
 		// Single root
 		&RootTransformer{},
 	}

terraform/graph_builder_apply_test.go

@@ -34,6 +34,7 @@ func TestApplyGraphBuilder(t *testing.T) {
 
 	b := &ApplyGraphBuilder{
 		Diff:      diff,
+		Providers: []string{"aws"},
 	}
 
 	g, err := b.Build(RootModulePath)
@@ -54,4 +55,6 @@ func TestApplyGraphBuilder(t *testing.T) {
 
 const testApplyGraphBuilderStr = `
 aws_instance.create
+  provider.aws
+provider.aws
 `

terraform/node_resource.go

@@ -1,10 +1,33 @@
 package terraform
 
-// NodeResource is a graph node for referencing a resource.
-type NodeResource struct {
+import (
+	"github.com/hashicorp/terraform/config"
+)
+
+// NodeApplyableResource represents a resource that is "applyable":
+// it is ready to be applied and is represented by a diff.
+type NodeApplyableResource struct {
 	Addr          *ResourceAddress // Addr is the address for this resource
+	Config        *config.Resource // Config is the resource in the config
+	ResourceState *ResourceState   // ResourceState is the ResourceState for this
 }
 
-func (n *NodeResource) Name() string {
+func (n *NodeApplyableResource) Name() string {
 	return n.Addr.String()
 }
+
+// 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)}
+	}
+
+	// If we have state, then we will use the provider from there
+	if n.ResourceState != nil {
+		return []string{n.ResourceState.Provider}
+	}
+
+	// Use our type
+	return []string{resourceProvider(n.Addr.Type, "")}
+}

terraform/resource_address.go

@@ -85,6 +85,17 @@ func (r *ResourceAddress) String() string {
 	return strings.Join(result, ".")
 }
 
+// parseResourceAddressConfig creates a resource address from a config.Resource
+func parseResourceAddressConfig(r *config.Resource) (*ResourceAddress, error) {
+	return &ResourceAddress{
+		Type:         r.Type,
+		Name:         r.Name,
+		Index:        -1,
+		InstanceType: TypePrimary,
+		Mode:         r.Mode,
+	}, nil
+}
+
 // parseResourceAddressInternal parses the somewhat bespoke resource
 // identifier used in states and diffs, such as "instance.name.0".
 func parseResourceAddressInternal(s string) (*ResourceAddress, error) {
@@ -101,6 +112,7 @@ func parseResourceAddressInternal(s string) (*ResourceAddress, error) {
 		Name:         parts[1],
 		Index:        -1,
 		InstanceType: TypePrimary,
+		Mode:         config.ManagedResourceMode,
 	}
 
 	// If we have more parts, then we have an index. Parse that.

terraform/transform_diff.go

@@ -2,6 +2,8 @@ package terraform
 
 import (
 	"fmt"
+
+	"github.com/hashicorp/terraform/config/module"
 )
 
 // DiffTransformer is a GraphTransformer that adds the elements of
@@ -9,8 +11,16 @@ import (
 //
 // This transform is used for example by the ApplyGraphBuilder to ensure
 // that only resources that are being modified are represented in the graph.
+//
+// Config and State is still required for the DiffTransformer for annotations
+// since the Diff doesn't contain all the information required to build the
+// complete graph (such as create-before-destroy information). The graph
+// is built based on the diff first, though, ensuring that only resources
+// that are being modified are present in the graph.
 type DiffTransformer struct {
 	Diff   *Diff
+	Config *module.Tree
+	State  *State
 }
 
 func (t *DiffTransformer) Transform(g *Graph) error {
@@ -20,6 +30,7 @@ func (t *DiffTransformer) Transform(g *Graph) error {
 	}
 
 	// Go through all the modules in the diff.
+	var nodes []*NodeApplyableResource
 	for _, m := range t.Diff.Modules {
 		// TODO: If this is a destroy diff then add a module destroy node
 
@@ -38,16 +49,75 @@ func (t *DiffTransformer) Transform(g *Graph) error {
 			// reference this resource.
 			addr, err := parseResourceAddressInternal(name)
 			if err != nil {
-				return fmt.Errorf(
-					"Error parsing internal name, this is a bug: %q", name)
+				panic(fmt.Sprintf(
+					"Error parsing internal name, this is a bug: %q", name))
 			}
 
+			// Very important: add the module path for this resource to
+			// the address. Remove "root" from it.
+			addr.Path = m.Path[1:]
+
 			// Add the resource to the graph
-			g.Add(&NodeResource{
+			nodes = append(nodes, &NodeApplyableResource{
 				Addr: addr,
 			})
 		}
 	}
 
+	// NOTE: Lots of room for performance optimizations below. For
+	// resource-heavy diffs this part alone is probably pretty slow.
+
+	// Annotate all nodes with their config and state
+	for _, n := range nodes {
+		// Grab the configuration at this path.
+		if t := t.Config.Child(n.Addr.Path); t != nil {
+			for _, r := range t.Config().Resources {
+				// Get a resource address so we can compare
+				addr, err := parseResourceAddressConfig(r)
+				if err != nil {
+					panic(fmt.Sprintf(
+						"Error parsing config address, this is a bug: %#v", r))
+				}
+				addr.Path = n.Addr.Path
+
+				// If this is not the same resource, then continue
+				if !addr.Equals(n.Addr) {
+					continue
+				}
+
+				// Same resource! Mark it and exit
+				n.Config = r
+				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
+	for _, n := range nodes {
+		g.Add(n)
+	}
+
 	return nil
 }