Merge pull request #25500 from hashicorp/jbardin/destroy-output-expand

Do not evaluate output when doing a full destroy

terraform/context_apply_test.go

@@ -6275,13 +6275,24 @@ func TestContext2Apply_destroyWithModuleVariableAndCountNested(t *testing.T) {
 
 func TestContext2Apply_destroyOutputs(t *testing.T) {
 	m := testModule(t, "apply-destroy-outputs")
-	p := testProvider("aws")
+	p := testProvider("test")
 	p.ApplyFn = testApplyFn
 	p.DiffFn = testDiffFn
+
+	p.ReadDataSourceFn = func(req providers.ReadDataSourceRequest) providers.ReadDataSourceResponse {
+		// add the required id
+		m := req.Config.AsValueMap()
+		m["id"] = cty.StringVal("foo")
+
+		return providers.ReadDataSourceResponse{
+			State: cty.ObjectVal(m),
+		}
+	}
+
 	ctx := testContext2(t, &ContextOpts{
 		Config: m,
 		Providers: map[addrs.Provider]providers.Factory{
-			addrs.NewDefaultProvider("aws"): testProviderFuncFixed(p),
+			addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
 		},
 	})
 
@@ -6302,7 +6313,7 @@ func TestContext2Apply_destroyOutputs(t *testing.T) {
 		State:   state,
 		Config:  m,
 		Providers: map[addrs.Provider]providers.Factory{
-			addrs.NewDefaultProvider("aws"): testProviderFuncFixed(p),
+			addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
 		},
 	})
 
@@ -6326,7 +6337,7 @@ func TestContext2Apply_destroyOutputs(t *testing.T) {
 		State:   state,
 		Config:  m,
 		Providers: map[addrs.Provider]providers.Factory{
-			addrs.NewDefaultProvider("aws"): testProviderFuncFixed(p),
+			addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
 		},
 	})
 	if _, diags := ctx.Plan(); diags.HasErrors() {

terraform/graph_builder_apply.go

@@ -165,7 +165,7 @@ func (b *ApplyGraphBuilder) Steps() []GraphTransformer {
 		// directly.  A destroy is identical to a normal apply, except for the
 		// fact that we also have configuration to evaluate. While the rest of
 		// the unused nodes can be programmatically pruned (via
-		// pruneUnusedNodesTransformer), root module outputs only have an
+		// pruneUnusedNodesTransformer), root module outputs always have an
 		// implied dependency on remote state. This means that if they exist in
 		// the configuration, the only signal to remove them is via the destroy
 		// command itself.

terraform/testdata/apply-destroy-outputs/main.tf

@@ -1,12 +1,26 @@
-resource "aws_instance" "foo" {
-    num = "2"
+data "test_data_source" "foo" {
+  foo = "ok"
 }
 
-resource "aws_instance" "bar" {
-    foo = "{aws_instance.foo.num}"
-    dep = "foo"
+locals {
+  l = [
+    {
+      name = data.test_data_source.foo.id
+      val = "null"
+    },
+  ]
+
+  m = { for v in local.l :
+    v.name => v
+  }
 }
 
-output "foo" {
-    value = "${aws_instance.foo.id}"
+resource "test_instance" "bar" {
+  for_each = local.m
+  foo = format("%s", each.value.name)
+  dep = each.value.val
+}
+
+output "out" {
+  value = test_instance.bar
 }

terraform/transform_destroy_edge.go

@@ -207,10 +207,10 @@ func (t *pruneUnusedNodesTransformer) Transform(g *Graph) error {
 		modules = append(modules, mod)
 	}
 
-	// Sort them by path length, longest first, so that start with the deepest
-	// modules.  The order of modules at the same tree level doesn't matter, we
-	// just need to ensure that child modules are processed before parent
-	// modules.
+	// Sort them by path length, longest first, so that we start with the
+	// deepest modules. The order of modules at the same tree level doesn't
+	// matter, we just need to ensure that child modules are processed before
+	// parent modules.
 	sort.Slice(modules, func(i, j int) bool {
 		return len(modules[i].addr) > len(modules[j].addr)
 	})

terraform/transform_output.go

@@ -88,13 +88,14 @@ func (t *destroyRootOutputTransformer) Transform(g *Graph) error {
 
 		deps := g.UpEdges(v)
 
-		// the destroy node must depend on the eval node
-		deps.Add(v)
-
 		for _, d := range deps {
 			log.Printf("[TRACE] %s depends on %s", node.Name(), dag.VertexName(d))
 			g.Connect(dag.BasicEdge(node, d))
 		}
+
+		// We no longer need the expand node, since we intend to remove this
+		// output from the state.
+		g.Remove(v)
 	}
 	return nil
 }