Merge #14098: correctly handle new/removed instances from count during refresh

builtin/providers/test/resource_data_dep_test.go

@@ -0,0 +1,224 @@
+package test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/hashicorp/terraform/helper/resource"
+	"github.com/hashicorp/terraform/terraform"
+)
+
+// TestResourceDataDep_alignedCountScaleOut tests to make sure interpolation
+// works (namely without index errors) when a data source and a resource share
+// the same count variable during scale-out with an existing state.
+func TestResourceDataDep_alignedCountScaleOut(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		Providers: testAccProviders,
+		CheckDestroy: func(s *terraform.State) error {
+			return nil
+		},
+		Steps: []resource.TestStep{
+			{
+				Config: testResourceDataDepConfig(2),
+			},
+			{
+				Config: testResourceDataDepConfig(4),
+				Check:  resource.TestCheckOutput("out", "value_from_api,value_from_api,value_from_api,value_from_api"),
+			},
+		},
+	})
+}
+
+// TestResourceDataDep_alignedCountScaleIn tests to make sure interpolation
+// works (namely without index errors) when a data source and a resource share
+// the same count variable during scale-in with an existing state.
+func TestResourceDataDep_alignedCountScaleIn(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		Providers: testAccProviders,
+		CheckDestroy: func(s *terraform.State) error {
+			return nil
+		},
+		Steps: []resource.TestStep{
+			{
+				Config: testResourceDataDepConfig(4),
+			},
+			{
+				Config: testResourceDataDepConfig(2),
+				Check:  resource.TestCheckOutput("out", "value_from_api,value_from_api"),
+			},
+		},
+	})
+}
+
+// TestDataResourceDep_alignedCountScaleOut functions like
+// TestResourceDataDep_alignedCountScaleOut, but with the dependencies swapped
+// (resource now depends on data source, a pretty regular use case, but
+// included here to check for regressions).
+func TestDataResourceDep_alignedCountScaleOut(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		Providers: testAccProviders,
+		CheckDestroy: func(s *terraform.State) error {
+			return nil
+		},
+		Steps: []resource.TestStep{
+			{
+				Config: testDataResourceDepConfig(2),
+			},
+			{
+				Config: testDataResourceDepConfig(4),
+				Check:  resource.TestCheckOutput("out", "test,test,test,test"),
+			},
+		},
+	})
+}
+
+// TestDataResourceDep_alignedCountScaleIn functions like
+// TestResourceDataDep_alignedCountScaleIn, but with the dependencies swapped
+// (resource now depends on data source, a pretty regular use case, but
+// included here to check for regressions).
+func TestDataResourceDep_alignedCountScaleIn(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		Providers: testAccProviders,
+		CheckDestroy: func(s *terraform.State) error {
+			return nil
+		},
+		Steps: []resource.TestStep{
+			{
+				Config: testDataResourceDepConfig(4),
+			},
+			{
+				Config: testDataResourceDepConfig(2),
+				Check:  resource.TestCheckOutput("out", "test,test"),
+			},
+		},
+	})
+}
+
+// TestResourceResourceDep_alignedCountScaleOut functions like
+// TestResourceDataDep_alignedCountScaleOut, but with a resource-to-resource
+// dependency instead, a pretty regular use case, but included here to check
+// for regressions.
+func TestResourceResourceDep_alignedCountScaleOut(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		Providers: testAccProviders,
+		CheckDestroy: func(s *terraform.State) error {
+			return nil
+		},
+		Steps: []resource.TestStep{
+			{
+				Config: testResourceResourceDepConfig(2),
+			},
+			{
+				Config: testResourceResourceDepConfig(4),
+				Check:  resource.TestCheckOutput("out", "test,test,test,test"),
+			},
+		},
+	})
+}
+
+// TestResourceResourceDep_alignedCountScaleIn functions like
+// TestResourceDataDep_alignedCountScaleIn, but with a resource-to-resource
+// dependency instead, a pretty regular use case, but included here to check
+// for regressions.
+func TestResourceResourceDep_alignedCountScaleIn(t *testing.T) {
+	resource.UnitTest(t, resource.TestCase{
+		Providers: testAccProviders,
+		CheckDestroy: func(s *terraform.State) error {
+			return nil
+		},
+		Steps: []resource.TestStep{
+			{
+				Config: testResourceResourceDepConfig(4),
+			},
+			{
+				Config: testResourceResourceDepConfig(2),
+				Check:  resource.TestCheckOutput("out", "test,test"),
+			},
+		},
+	})
+}
+
+func testResourceDataDepConfig(count int) string {
+	return fmt.Sprintf(`
+variable count {
+  default = "%d"
+}
+
+resource "test_resource" "foo" {
+  count    = "${var.count}"
+  required = "yes"
+
+  required_map = {
+    "foo" = "bar"
+  }
+}
+
+data "test_data_source" "bar" {
+  count = "${var.count}"
+  input = "${test_resource.foo.*.computed_read_only[count.index]}"
+}
+
+output "out" {
+	value = "${join(",", data.test_data_source.bar.*.output)}"
+}
+`, count)
+}
+
+func testDataResourceDepConfig(count int) string {
+	return fmt.Sprintf(`
+variable count {
+  default = "%d"
+}
+
+data "test_data_source" "foo" {
+  count = "${var.count}"
+  input = "test"
+}
+
+resource "test_resource" "bar" {
+  count    = "${var.count}"
+  required = "yes"
+  optional = "${data.test_data_source.foo.*.output[count.index]}"
+
+  required_map = {
+    "foo" = "bar"
+  }
+}
+
+output "out" {
+  value = "${join(",", test_resource.bar.*.optional)}"
+}
+`, count)
+}
+
+func testResourceResourceDepConfig(count int) string {
+	return fmt.Sprintf(`
+variable count {
+  default = "%d"
+}
+
+resource "test_resource" "foo" {
+  count    = "${var.count}"
+  required = "yes"
+  optional = "test"
+
+  required_map = {
+    "foo" = "bar"
+  }
+}
+
+resource "test_resource" "bar" {
+  count    = "${var.count}"
+  required = "yes"
+  optional = "${test_resource.foo.*.optional[count.index]}"
+
+  required_map = {
+    "foo" = "bar"
+  }
+}
+
+output "out" {
+  value = "${join(",", test_resource.bar.*.optional)}"
+}
+`, count)
+}

terraform/graph_builder_refresh.go

@@ -1,6 +1,8 @@
 package terraform
 
 import (
+	"log"
+
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/config/module"
 	"github.com/hashicorp/terraform/dag"
@@ -56,8 +58,16 @@ func (b *RefreshGraphBuilder) Steps() []GraphTransformer {
 		}
 	}
 
-	concreteResource := func(a *NodeAbstractResource) dag.Vertex {
+	concreteManagedResource := func(a *NodeAbstractResource) dag.Vertex {
-		return &NodeRefreshableResource{
+		return &NodeRefreshableManagedResource{
+			NodeAbstractCountResource: &NodeAbstractCountResource{
+				NodeAbstractResource: a,
+			},
+		}
+	}
+
+	concreteManagedResourceInstance := func(a *NodeAbstractResource) dag.Vertex {
+		return &NodeRefreshableManagedResourceInstance{
 			NodeAbstractResource: a,
 		}
 	}
@@ -71,13 +81,25 @@ func (b *RefreshGraphBuilder) Steps() []GraphTransformer {
 	}
 
 	steps := []GraphTransformer{
-		// Creates all the resources represented in the state
+		// Creates all the managed resources that aren't in the state, but only if
-		&StateTransformer{
+		// we have a state already. No resources in state means there's not
-			Concrete: concreteResource,
+		// anything to refresh.
-			State:    b.State,
+		func() GraphTransformer {
-		},
+			if b.State.HasResources() {
+				return &ConfigTransformer{
+					Concrete:   concreteManagedResource,
+					Module:     b.Module,
+					Unique:     true,
+					ModeFilter: true,
+					Mode:       config.ManagedResourceMode,
+				}
+			}
+			log.Println("[TRACE] No managed resources in state during refresh, skipping managed resource transformer")
+			return nil
+		}(),
 
-		// Creates all the data resources that aren't in the state
+		// Creates all the data resources that aren't in the state. This will also
+		// add any orphans from scaling in as destroy nodes.
 		&ConfigTransformer{
 			Concrete:   concreteDataResource,
 			Module:     b.Module,
@@ -86,6 +108,15 @@ func (b *RefreshGraphBuilder) Steps() []GraphTransformer {
 			Mode:       config.DataResourceMode,
 		},
 
+		// Add any fully-orphaned resources from config (ones that have been
+		// removed completely, not ones that are just orphaned due to a scaled-in
+		// count.
+		&OrphanResourceTransformer{
+			Concrete: concreteManagedResourceInstance,
+			State:    b.State,
+			Module:   b.Module,
+		},
+
 		// Attach the state
 		&AttachStateTransformer{State: b.State},
 

terraform/graph_builder_refresh_test.go

@@ -0,0 +1,96 @@
+package terraform
+
+import "testing"
+
+func TestRefreshGraphBuilder_configOrphans(t *testing.T) {
+
+	m := testModule(t, "refresh-config-orphan")
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "foo",
+							},
+						},
+					},
+					"aws_instance.foo.1": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "bar",
+							},
+						},
+					},
+					"aws_instance.foo.2": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "baz",
+							},
+						},
+					},
+					"data.aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "foo",
+							},
+						},
+					},
+					"data.aws_instance.foo.1": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "bar",
+							},
+						},
+					},
+					"data.aws_instance.foo.2": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "baz",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	b := &RefreshGraphBuilder{
+		Module:    m,
+		State:     state,
+		Providers: []string{"aws"},
+	}
+	g, err := b.Build(rootModulePath)
+	if err != nil {
+		t.Fatalf("Error building graph: %s", err)
+	}
+
+	actual := g.StringWithNodeTypes()
+	expected := `aws_instance.foo - *terraform.NodeRefreshableManagedResource
+  provider.aws - *terraform.NodeApplyableProvider
+data.aws_instance.foo[0] - *terraform.NodeRefreshableManagedResourceInstance
+  provider.aws - *terraform.NodeApplyableProvider
+data.aws_instance.foo[1] - *terraform.NodeRefreshableManagedResourceInstance
+  provider.aws - *terraform.NodeApplyableProvider
+data.aws_instance.foo[2] - *terraform.NodeRefreshableManagedResourceInstance
+  provider.aws - *terraform.NodeApplyableProvider
+provider.aws - *terraform.NodeApplyableProvider
+provider.aws (close) - *terraform.graphNodeCloseProvider
+  aws_instance.foo - *terraform.NodeRefreshableManagedResource
+  data.aws_instance.foo[0] - *terraform.NodeRefreshableManagedResourceInstance
+  data.aws_instance.foo[1] - *terraform.NodeRefreshableManagedResourceInstance
+  data.aws_instance.foo[2] - *terraform.NodeRefreshableManagedResourceInstance
+`
+	if expected != actual {
+		t.Fatalf("Expected:\n%s\nGot:\n%s", expected, actual)
+	}
+}

terraform/node_data_refresh.go

@@ -33,6 +33,17 @@ func (n *NodeRefreshableDataResource) DynamicExpand(ctx EvalContext) (*Graph, er
 		}
 	}
 
+	// We also need a destroyable resource for orphans that are a result of a
+	// scaled-in count.
+	concreteResourceDestroyable := func(a *NodeAbstractResource) dag.Vertex {
+		// Add the config since we don't do that via transforms
+		a.Config = n.Config
+
+		return &NodeDestroyableDataResource{
+			NodeAbstractResource: a,
+		}
+	}
+
 	// Start creating the steps
 	steps := []GraphTransformer{
 		// Expand the count.
@@ -42,6 +53,15 @@ func (n *NodeRefreshableDataResource) DynamicExpand(ctx EvalContext) (*Graph, er
 			Addr:     n.ResourceAddr(),
 		},
 
+		// Add the count orphans. As these are orphaned refresh nodes, we add them
+		// directly as NodeDestroyableDataResource.
+		&OrphanResourceCountTransformer{
+			Concrete: concreteResourceDestroyable,
+			Count:    count,
+			Addr:     n.ResourceAddr(),
+			State:    state,
+		},
+
 		// Attach the state
 		&AttachStateTransformer{State: state},
 

terraform/node_data_refresh_test.go

@@ -0,0 +1,154 @@
+package terraform
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestNodeRefreshableDataResourceDynamicExpand_scaleOut(t *testing.T) {
+	var stateLock sync.RWMutex
+
+	addr, err := ParseResourceAddress("data.aws_instance.foo")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	m := testModule(t, "refresh-data-scale-inout")
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"data.aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "foo",
+							},
+						},
+					},
+					"data.aws_instance.foo.1": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "bar",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	n := &NodeRefreshableDataResource{
+		NodeAbstractCountResource: &NodeAbstractCountResource{
+			NodeAbstractResource: &NodeAbstractResource{
+				Addr:   addr,
+				Config: m.Config().Resources[0],
+			},
+		},
+	}
+
+	g, err := n.DynamicExpand(&MockEvalContext{
+		PathPath:   []string{"root"},
+		StateState: state,
+		StateLock:  &stateLock,
+	})
+
+	actual := g.StringWithNodeTypes()
+	expected := `data.aws_instance.foo[0] - *terraform.NodeRefreshableDataResourceInstance
+data.aws_instance.foo[1] - *terraform.NodeRefreshableDataResourceInstance
+data.aws_instance.foo[2] - *terraform.NodeRefreshableDataResourceInstance
+root - terraform.graphNodeRoot
+  data.aws_instance.foo[0] - *terraform.NodeRefreshableDataResourceInstance
+  data.aws_instance.foo[1] - *terraform.NodeRefreshableDataResourceInstance
+  data.aws_instance.foo[2] - *terraform.NodeRefreshableDataResourceInstance
+`
+	if expected != actual {
+		t.Fatalf("Expected:\n%s\nGot:\n%s", expected, actual)
+	}
+}
+
+func TestNodeRefreshableDataResourceDynamicExpand_scaleIn(t *testing.T) {
+	var stateLock sync.RWMutex
+
+	addr, err := ParseResourceAddress("data.aws_instance.foo")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	m := testModule(t, "refresh-data-scale-inout")
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"data.aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "foo",
+							},
+						},
+					},
+					"data.aws_instance.foo.1": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "bar",
+							},
+						},
+					},
+					"data.aws_instance.foo.2": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "baz",
+							},
+						},
+					},
+					"data.aws_instance.foo.3": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "qux",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	n := &NodeRefreshableDataResource{
+		NodeAbstractCountResource: &NodeAbstractCountResource{
+			NodeAbstractResource: &NodeAbstractResource{
+				Addr:   addr,
+				Config: m.Config().Resources[0],
+			},
+		},
+	}
+
+	g, err := n.DynamicExpand(&MockEvalContext{
+		PathPath:   []string{"root"},
+		StateState: state,
+		StateLock:  &stateLock,
+	})
+
+	actual := g.StringWithNodeTypes()
+	expected := `data.aws_instance.foo[0] - *terraform.NodeRefreshableDataResourceInstance
+data.aws_instance.foo[1] - *terraform.NodeRefreshableDataResourceInstance
+data.aws_instance.foo[2] - *terraform.NodeRefreshableDataResourceInstance
+data.aws_instance.foo[3] - *terraform.NodeDestroyableDataResource
+root - terraform.graphNodeRoot
+  data.aws_instance.foo[0] - *terraform.NodeRefreshableDataResourceInstance
+  data.aws_instance.foo[1] - *terraform.NodeRefreshableDataResourceInstance
+  data.aws_instance.foo[2] - *terraform.NodeRefreshableDataResourceInstance
+  data.aws_instance.foo[3] - *terraform.NodeDestroyableDataResource
+`
+	if expected != actual {
+		t.Fatalf("Expected:\n%s\nGot:\n%s", expected, actual)
+	}
+}

terraform/node_resource_refresh.go

@@ -4,21 +4,99 @@ import (
 	"fmt"
 
 	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/dag"
 )
 
-// NodeRefreshableResource represents a resource that is "applyable":
+// NodeRefreshableManagedResource represents a resource that is expanabled into
+// NodeRefreshableManagedResourceInstance. Resource count orphans are also added.
+type NodeRefreshableManagedResource struct {
+	*NodeAbstractCountResource
+}
+
+// GraphNodeDynamicExpandable
+func (n *NodeRefreshableManagedResource) DynamicExpand(ctx EvalContext) (*Graph, error) {
+	// Grab the state which we read
+	state, lock := ctx.State()
+	lock.RLock()
+	defer lock.RUnlock()
+
+	// Expand the resource count which must be available by now from EvalTree
+	count, err := n.Config.Count()
+	if err != nil {
+		return nil, err
+	}
+
+	// The concrete resource factory we'll use
+	concreteResource := func(a *NodeAbstractResource) dag.Vertex {
+		// Add the config and state since we don't do that via transforms
+		a.Config = n.Config
+
+		return &NodeRefreshableManagedResourceInstance{
+			NodeAbstractResource: a,
+		}
+	}
+
+	// Start creating the steps
+	steps := []GraphTransformer{
+		// Expand the count.
+		&ResourceCountTransformer{
+			Concrete: concreteResource,
+			Count:    count,
+			Addr:     n.ResourceAddr(),
+		},
+
+		// Switch up any node missing state to a plannable resource. This helps
+		// catch cases where data sources depend on the counts from this resource
+		// during a scale out.
+		&ResourceRefreshPlannableTransformer{
+			State: state,
+		},
+
+		// Add the count orphans to make sure these resources are accounted for
+		// during a scale in.
+		&OrphanResourceCountTransformer{
+			Concrete: concreteResource,
+			Count:    count,
+			Addr:     n.ResourceAddr(),
+			State:    state,
+		},
+
+		// Attach the state
+		&AttachStateTransformer{State: state},
+
+		// Targeting
+		&TargetsTransformer{ParsedTargets: n.Targets},
+
+		// Connect references so ordering is correct
+		&ReferenceTransformer{},
+
+		// Make sure there is a single root
+		&RootTransformer{},
+	}
+
+	// Build the graph
+	b := &BasicGraphBuilder{
+		Steps:    steps,
+		Validate: true,
+		Name:     "NodeRefreshableManagedResource",
+	}
+
+	return b.Build(ctx.Path())
+}
+
+// NodeRefreshableManagedResourceInstance represents a resource that is "applyable":
 // it is ready to be applied and is represented by a diff.
-type NodeRefreshableResource struct {
+type NodeRefreshableManagedResourceInstance struct {
 	*NodeAbstractResource
 }
 
 // GraphNodeDestroyer
-func (n *NodeRefreshableResource) DestroyAddr() *ResourceAddress {
+func (n *NodeRefreshableManagedResourceInstance) DestroyAddr() *ResourceAddress {
 	return n.Addr
 }
 
 // GraphNodeEvalable
-func (n *NodeRefreshableResource) EvalTree() EvalNode {
+func (n *NodeRefreshableManagedResourceInstance) EvalTree() EvalNode {
 	// Eval info is different depending on what kind of resource this is
 	switch mode := n.Addr.Mode; mode {
 	case config.ManagedResourceMode:
@@ -44,7 +122,7 @@ func (n *NodeRefreshableResource) EvalTree() EvalNode {
 	}
 }
 
-func (n *NodeRefreshableResource) evalTreeManagedResource() EvalNode {
+func (n *NodeRefreshableManagedResourceInstance) evalTreeManagedResource() EvalNode {
 	addr := n.NodeAbstractResource.Addr
 
 	// stateId is the ID to put into the state

terraform/node_resource_refresh_test.go

@@ -0,0 +1,154 @@
+package terraform
+
+import (
+	"sync"
+	"testing"
+)
+
+func TestNodeRefreshableManagedResourceDynamicExpand_scaleOut(t *testing.T) {
+	var stateLock sync.RWMutex
+
+	addr, err := ParseResourceAddress("aws_instance.foo")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	m := testModule(t, "refresh-resource-scale-inout")
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "foo",
+							},
+						},
+					},
+					"aws_instance.foo.1": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "bar",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	n := &NodeRefreshableManagedResource{
+		NodeAbstractCountResource: &NodeAbstractCountResource{
+			NodeAbstractResource: &NodeAbstractResource{
+				Addr:   addr,
+				Config: m.Config().Resources[0],
+			},
+		},
+	}
+
+	g, err := n.DynamicExpand(&MockEvalContext{
+		PathPath:   []string{"root"},
+		StateState: state,
+		StateLock:  &stateLock,
+	})
+
+	actual := g.StringWithNodeTypes()
+	expected := `aws_instance.foo[0] - *terraform.NodeRefreshableManagedResourceInstance
+aws_instance.foo[1] - *terraform.NodeRefreshableManagedResourceInstance
+aws_instance.foo[2] - *terraform.NodePlannableResourceInstance
+root - terraform.graphNodeRoot
+  aws_instance.foo[0] - *terraform.NodeRefreshableManagedResourceInstance
+  aws_instance.foo[1] - *terraform.NodeRefreshableManagedResourceInstance
+  aws_instance.foo[2] - *terraform.NodePlannableResourceInstance
+`
+	if expected != actual {
+		t.Fatalf("Expected:\n%s\nGot:\n%s", expected, actual)
+	}
+}
+
+func TestNodeRefreshableManagedResourceDynamicExpand_scaleIn(t *testing.T) {
+	var stateLock sync.RWMutex
+
+	addr, err := ParseResourceAddress("aws_instance.foo")
+	if err != nil {
+		t.Fatalf("bad: %s", err)
+	}
+
+	m := testModule(t, "refresh-resource-scale-inout")
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: rootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "foo",
+							},
+						},
+					},
+					"aws_instance.foo.1": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "bar",
+							},
+						},
+					},
+					"aws_instance.foo.2": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "baz",
+							},
+						},
+					},
+					"aws_instance.foo.3": &ResourceState{
+						Type: "aws_instance",
+						Deposed: []*InstanceState{
+							&InstanceState{
+								ID: "qux",
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	n := &NodeRefreshableManagedResource{
+		NodeAbstractCountResource: &NodeAbstractCountResource{
+			NodeAbstractResource: &NodeAbstractResource{
+				Addr:   addr,
+				Config: m.Config().Resources[0],
+			},
+		},
+	}
+
+	g, err := n.DynamicExpand(&MockEvalContext{
+		PathPath:   []string{"root"},
+		StateState: state,
+		StateLock:  &stateLock,
+	})
+
+	actual := g.StringWithNodeTypes()
+	expected := `aws_instance.foo[0] - *terraform.NodeRefreshableManagedResourceInstance
+aws_instance.foo[1] - *terraform.NodeRefreshableManagedResourceInstance
+aws_instance.foo[2] - *terraform.NodeRefreshableManagedResourceInstance
+aws_instance.foo[3] - *terraform.NodeRefreshableManagedResourceInstance
+root - terraform.graphNodeRoot
+  aws_instance.foo[0] - *terraform.NodeRefreshableManagedResourceInstance
+  aws_instance.foo[1] - *terraform.NodeRefreshableManagedResourceInstance
+  aws_instance.foo[2] - *terraform.NodeRefreshableManagedResourceInstance
+  aws_instance.foo[3] - *terraform.NodeRefreshableManagedResourceInstance
+`
+	if expected != actual {
+		t.Fatalf("Expected:\n%s\nGot:\n%s", expected, actual)
+	}
+}

terraform/test-fixtures/refresh-config-orphan/main.tf

@@ -0,0 +1,3 @@
+resource "aws_instance" "foo" {
+  count = 3
+}

terraform/test-fixtures/refresh-data-scale-inout/main.tf

@@ -0,0 +1,3 @@
+data "aws_instance" "foo" {
+  count = 3
+}

terraform/test-fixtures/refresh-resource-scale-inout/main.tf

@@ -0,0 +1,3 @@
+resource "aws_instance" "foo" {
+  count = 3
+}

terraform/transform_resource_refresh_plannable.go

@@ -0,0 +1,55 @@
+package terraform
+
+import (
+	"fmt"
+	"log"
+)
+
+// ResourceRefreshPlannableTransformer is a GraphTransformer that replaces any
+// nodes that don't have state yet exist in config with
+// NodePlannableResourceInstance.
+//
+// This transformer is used when expanding count on managed resource nodes
+// during the refresh phase to ensure that data sources that have
+// interpolations that depend on resources existing in the graph can be walked
+// properly.
+type ResourceRefreshPlannableTransformer struct {
+	// The full global state.
+	State *State
+}
+
+// Transform implements GraphTransformer for
+// ResourceRefreshPlannableTransformer.
+func (t *ResourceRefreshPlannableTransformer) Transform(g *Graph) error {
+nextVertex:
+	for _, v := range g.Vertices() {
+		addr := v.(*NodeRefreshableManagedResourceInstance).Addr
+
+		// Find the state for this address, if there is one
+		filter := &StateFilter{State: t.State}
+		results, err := filter.Filter(addr.String())
+		if err != nil {
+			return err
+		}
+
+		// Check to see if we have a state for this resource. If we do, skip this
+		// node.
+		for _, result := range results {
+			if _, ok := result.Value.(*ResourceState); ok {
+				continue nextVertex
+			}
+		}
+		// If we don't, convert this resource to a NodePlannableResourceInstance node
+		// with all of the data we need to make it happen.
+		log.Printf("[TRACE] No state for %s, converting to NodePlannableResourceInstance", addr.String())
+		new := &NodePlannableResourceInstance{
+			NodeAbstractResource: v.(*NodeRefreshableManagedResourceInstance).NodeAbstractResource,
+		}
+		// Replace the node in the graph
+		if !g.Replace(v, new) {
+			return fmt.Errorf("ResourceRefreshPlannableTransformer: Could not replace node %#v with %#v", v, new)
+		}
+	}
+
+	return nil
+}