refresh should not modify state deps

Don't modify dependencies or depends_on during refresh, just restore
what was already in the instance state.

terraform/context_refresh_test.go

@@ -1,6 +1,7 @@
 package terraform
 
 import (
+	"fmt"
 	"reflect"
 	"regexp"
 	"sort"
@@ -1965,24 +1966,10 @@ func TestContext2Refresh_dataResourceDependsOn(t *testing.T) {
 	}
 }
 
-// verify that dependencies are updated in the state during refresh
-func TestRefresh_updateDependencies(t *testing.T) {
+// verify that dependencies are maintained in the state during refresh
+func TestRefresh_maintainDependencies(t *testing.T) {
 	state := states.NewState()
 	root := state.EnsureModule(addrs.RootModuleInstance)
-	root.SetResourceInstanceCurrent(
-		addrs.Resource{
-			Mode: addrs.ManagedResourceMode,
-			Type: "aws_instance",
-			Name: "foo",
-		}.Instance(addrs.NoKey),
-		&states.ResourceInstanceObjectSrc{
-			Status:    states.ObjectReady,
-			AttrsJSON: []byte(`{"id":"foo"}`),
-		},
-		addrs.ProviderConfig{
-			Type: "aws",
-		}.Absolute(addrs.RootModuleInstance),
-	)
 	root.SetResourceInstanceCurrent(
 		addrs.Resource{
 			Mode: addrs.ManagedResourceMode,
@@ -1993,7 +1980,7 @@ func TestRefresh_updateDependencies(t *testing.T) {
 			Status:    states.ObjectReady,
 			AttrsJSON: []byte(`{"id":"bar","foo":"foo"}`),
 			Dependencies: []addrs.AbsResource{
-				// Existing dependencies should not be removed during refresh
+				// Existing dependencies should not be changed during refresh
 				{
 					Module: addrs.RootModuleInstance,
 					Resource: addrs.Resource{
@@ -2003,6 +1990,15 @@ func TestRefresh_updateDependencies(t *testing.T) {
 					},
 				},
 			},
+			DependsOn: []addrs.Referenceable{
+				addrs.ResourceInstance{
+					Resource: addrs.Resource{
+						Mode: addrs.ManagedResourceMode,
+						Type: "aws_instance",
+						Name: "zab",
+					},
+				},
+			},
 		},
 		addrs.ProviderConfig{
 			Type: "aws",
@@ -2012,10 +2008,6 @@ func TestRefresh_updateDependencies(t *testing.T) {
 	m := testModuleInline(t, map[string]string{
 		"main.tf": `
 resource "aws_instance" "bar" {
-  foo = aws_instance.foo.id
-}
-
-resource "aws_instance" "foo" {
 }`,
 	})
 
@@ -2038,19 +2030,19 @@ resource "aws_instance" "foo" {
 		t.Fatalf("plan errors: %s", diags.Err())
 	}
 
-	expect := strings.TrimSpace(`
-aws_instance.bar:
-  ID = bar
-  provider = provider.aws
-  foo = foo
-
-  Dependencies:
-    aws_instance.baz
-    aws_instance.foo
-aws_instance.foo:
-  ID = foo
-  provider = provider.aws
-`)
+	bar := result.RootModule().ResourceInstance(addrs.Resource{
+		Mode: addrs.ManagedResourceMode,
+		Type: "aws_instance",
+		Name: "bar",
+	}.Instance(addrs.NoKey))
 
-	checkStateString(t, result, expect)
+	depString := fmt.Sprintf("%v", bar.Current.Dependencies)
+	doString := fmt.Sprintf("%v", bar.Current.DependsOn)
+	if depString != "[aws_instance.baz]" {
+		t.Fatal("expected Dependencies of [aws_instance.baz], got:", depString)
+	}
+
+	if doString != "[aws_instance.zab]" {
+		t.Fatal("expected DependsOn of [aws_isntance.zab], got:", doString)
+	}
 }

terraform/eval_refresh.go

@@ -90,6 +90,7 @@ func (n *EvalRefresh) Eval(ctx EvalContext) (interface{}, error) {
 	newState.Value = resp.NewState
 	newState.Private = resp.Private
 	newState.Dependencies = state.Dependencies
+	newState.DependsOn = state.DependsOn
 
 	// Call post-refresh hook
 	err = ctx.Hook(func(h Hook) (HookAction, error) {

terraform/eval_state.go

@@ -3,7 +3,6 @@ package terraform
 import (
 	"fmt"
 	"log"
-	"sort"
 
 	"github.com/hashicorp/terraform/addrs"
 	"github.com/hashicorp/terraform/configs"
@@ -232,6 +231,9 @@ func (n *EvalWriteState) Eval(ctx EvalContext) (interface{}, error) {
 	if n.Dependencies != nil {
 		log.Printf("[TRACE] EvalWriteState: recording %d dependencies for %s", len(*n.Dependencies), absAddr)
 		obj.Dependencies = *n.Dependencies
+
+		// If we have Dependencies, then we need to replace any old DependsOn values
+		obj.DependsOn = nil
 	}
 
 	if n.ProviderSchema == nil || *n.ProviderSchema == nil {
@@ -484,44 +486,3 @@ func (n *EvalForgetResourceState) Eval(ctx EvalContext) (interface{}, error) {
 
 	return nil, nil
 }
-
-// EvalRefreshDependencies is an EvalNode implementation that appends any newly
-// found dependencies to those saved in the state. The existing dependencies
-// are retained, as they may be missing from the config, and will be required
-// for the updates and destroys during the next apply.
-type EvalRefreshDependencies struct {
-	// Prior State
-	State **states.ResourceInstanceObject
-	// Dependencies to write to the new state
-	Dependencies *[]addrs.AbsResource
-}
-
-func (n *EvalRefreshDependencies) Eval(ctx EvalContext) (interface{}, error) {
-	state := *n.State
-	if state == nil {
-		// no existing state to append
-		return nil, nil
-	}
-
-	depMap := make(map[string]addrs.AbsResource)
-	for _, d := range *n.Dependencies {
-		depMap[d.String()] = d
-	}
-
-	for _, d := range state.Dependencies {
-		depMap[d.String()] = d
-	}
-
-	deps := make([]addrs.AbsResource, 0, len(depMap))
-	for _, d := range depMap {
-		deps = append(deps, d)
-	}
-
-	sort.Slice(deps, func(i, j int) bool {
-		return deps[i].String() < deps[j].String()
-	})
-
-	*n.Dependencies = deps
-
-	return nil, nil
-}

terraform/graph_builder_refresh.go

@@ -165,7 +165,6 @@ func (b *RefreshGraphBuilder) Steps() []GraphTransformer {
 		// Connect so that the references are ready for targeting. We'll
 		// have to connect again later for providers and so on.
 		&ReferenceTransformer{},
-		&AttachDependenciesTransformer{},
 
 		// Target
 		&TargetsTransformer{

terraform/node_resource_refresh.go

@@ -186,6 +186,8 @@ func (n *NodeRefreshableManagedResourceInstance) evalTreeManagedResource() EvalN
 	var provider providers.Interface
 	var providerSchema *ProviderSchema
 	var state *states.ResourceInstanceObject
+	//var dependencies []addrs.AbsResource
+	//var dependsOn []addrs.Referenceable
 
 	// This happened during initial development. All known cases were
 	// fixed and tested but as a sanity check let's assert here.
@@ -210,13 +212,7 @@ func (n *NodeRefreshableManagedResourceInstance) evalTreeManagedResource() EvalN
 				Addr:           addr.Resource,
 				Provider:       &provider,
 				ProviderSchema: &providerSchema,
-
-				Output: &state,
-			},
-
-			&EvalRefreshDependencies{
-				State:        &state,
-				Dependencies: &n.Dependencies,
+				Output:         &state,
 			},
 
 			&EvalRefresh{
@@ -233,7 +229,6 @@ func (n *NodeRefreshableManagedResourceInstance) evalTreeManagedResource() EvalN
 				ProviderAddr:   n.ResolvedProvider,
 				ProviderSchema: &providerSchema,
 				State:          &state,
-				Dependencies:   &n.Dependencies,
 			},
 		},
 	}