Complete implementation of PreventRemoval

Resolves hashicorp#17599

internal/states/instance_object.go

@@ -44,6 +44,13 @@ type ResourceInstanceObject struct {
 	// destroy operations, we need to record the status to ensure a resource
 	// removed from the config will still be destroyed in the same manner.
 	CreateBeforeDestroy bool
+
+	// PreventRemoval is a lifecycle option that can be set on a resource
+	// instance to prevent it from being removed from state. This is useful
+	// for preventing a stateful resource from being removed unexpectedly,
+	// regardless of whether it is still present in configuration.
+	// This can be thought of as a stronger version of prevent_destroy.
+	PreventRemoval bool
 }
 
 // ObjectStatus represents the status of a RemoteObject.
@@ -130,6 +137,7 @@ func (o *ResourceInstanceObject) Encode(ty cty.Type, schemaVersion uint64) (*Res
 		Status:              o.Status,
 		Dependencies:        dependencies,
 		CreateBeforeDestroy: o.CreateBeforeDestroy,
+		PreventRemoval:      o.PreventRemoval,
 	}, nil
 }
 

internal/states/instance_object_src.go

@@ -59,6 +59,7 @@ type ResourceInstanceObjectSrc struct {
 	Status              ObjectStatus
 	Dependencies        []addrs.ConfigResource
 	CreateBeforeDestroy bool
+	PreventRemoval      bool
 }
 
 // Decode unmarshals the raw representation of the object attributes. Pass the
@@ -97,6 +98,7 @@ func (os *ResourceInstanceObjectSrc) Decode(ty cty.Type) (*ResourceInstanceObjec
 		Dependencies:        os.Dependencies,
 		Private:             os.Private,
 		CreateBeforeDestroy: os.CreateBeforeDestroy,
+		PreventRemoval:      os.PreventRemoval,
 	}, nil
 }
 

internal/states/state_deepcopy.go

@@ -174,6 +174,7 @@ func (os *ResourceInstanceObjectSrc) DeepCopy() *ResourceInstanceObjectSrc {
 		AttrSensitivePaths:  attrPaths,
 		Dependencies:        dependencies,
 		CreateBeforeDestroy: os.CreateBeforeDestroy,
+		PreventRemoval:      os.PreventRemoval,
 	}
 }
 
@@ -210,6 +211,7 @@ func (o *ResourceInstanceObject) DeepCopy() *ResourceInstanceObject {
 		Private:             private,
 		Dependencies:        dependencies,
 		CreateBeforeDestroy: o.CreateBeforeDestroy,
+		PreventRemoval:      o.PreventRemoval,
 	}
 }
 

internal/states/statefile/version4.go

@@ -136,6 +136,7 @@ func prepareStateV4(sV4 *stateV4) (*File, tfdiags.Diagnostics) {
 			obj := &states.ResourceInstanceObjectSrc{
 				SchemaVersion:       isV4.SchemaVersion,
 				CreateBeforeDestroy: isV4.CreateBeforeDestroy,
+				PreventRemoval:      isV4.PreventRemoval,
 			}
 
 			{
@@ -507,6 +508,7 @@ func appendInstanceObjectStateV4(rs *states.Resource, is *states.ResourceInstanc
 		PrivateRaw:              privateRaw,
 		Dependencies:            deps,
 		CreateBeforeDestroy:     obj.CreateBeforeDestroy,
+		PreventRemoval:          obj.PreventRemoval,
 	}), diags
 }
 
@@ -708,6 +710,8 @@ type instanceObjectStateV4 struct {
 	Dependencies []string `json:"dependencies,omitempty"`
 
 	CreateBeforeDestroy bool `json:"create_before_destroy,omitempty"`
+
+	PreventRemoval bool `json:"prevent_removal,omitempty"`
 }
 
 type checkResultsV4 struct {

internal/terraform/node_resource_abstract_instance.go

@@ -157,22 +157,37 @@ func (n *NodeAbstractResourceInstance) readDiff(ctx EvalContext, providerSchema
 }
 
 func (n *NodeAbstractResourceInstance) checkPreventDestroy(change *plans.ResourceInstanceChange) error {
-	if change == nil || n.Config == nil || n.Config.Managed == nil {
+	if change == nil {
 		return nil
 	}
 
-	preventDestroy := n.Config.Managed.PreventDestroy
+	preventDestroy := false
+
+	// if prevent_destroy is set, then we should prevent destroy
+	if n.Config != nil && n.Config.Managed != nil {
+		preventDestroy = preventDestroy || n.Config.Managed.PreventDestroy
+	}
+
+	// if there's a prevent_removal is true in the state, then we should prevent destroy
+	if n.instanceState != nil && n.instanceState.Current != nil {
+		preventDestroy = preventDestroy || n.instanceState.Current.PreventRemoval
+	}
 
 	if (change.Action == plans.Delete || change.Action.IsReplace()) && preventDestroy {
+		var subject *hcl.Range
+		if n.Config != nil {
+			subject = &n.Config.DeclRange
+		}
+
 		var diags tfdiags.Diagnostics
 		diags = diags.Append(&hcl.Diagnostic{
 			Severity: hcl.DiagError,
 			Summary:  "Instance cannot be destroyed",
 			Detail: fmt.Sprintf(
-				"Resource %s has lifecycle.prevent_destroy set, but the plan calls for this resource to be destroyed. To avoid this error and continue with the plan, either disable lifecycle.prevent_destroy or reduce the scope of the plan using the -target flag.",
+				"Resource %s has lifecycle.prevent_destroy or had lifecycle.prevent_removal set, but the plan calls for this resource to be destroyed. To avoid this error and continue with the plan, either disable lifecycle.prevent_destroy and lifecycle.prevent_removal, or reduce the scope of the plan using the -target flag.",
 				n.Addr.String(),
 			),
-			Subject: &n.Config.DeclRange,
+			Subject: subject,
 		})
 		return diags.Err()
 	}
@@ -2152,6 +2167,7 @@ func (n *NodeAbstractResourceInstance) apply(
 	if change.Action == plans.Update && eq && !marksEqual(beforePaths, afterPaths) {
 		// Copy the previous state, changing only the value
 		newState := &states.ResourceInstanceObject{
+			PreventRemoval:      state.PreventRemoval,
 			CreateBeforeDestroy: state.CreateBeforeDestroy,
 			Dependencies:        state.Dependencies,
 			Private:             state.Private,
@@ -2364,6 +2380,7 @@ func (n *NodeAbstractResourceInstance) apply(
 			Value:               newVal,
 			Private:             resp.Private,
 			CreateBeforeDestroy: createBeforeDestroy,
+			PreventRemoval:      state.PreventRemoval,
 		}
 
 		// if the resource was being deleted, the dependencies are not going to
@@ -2381,6 +2398,7 @@ func (n *NodeAbstractResourceInstance) apply(
 			Value:               newVal,
 			Private:             resp.Private,
 			CreateBeforeDestroy: createBeforeDestroy,
+			PreventRemoval:      applyConfig.Managed.PreventRemoval,
 		}
 		return newState, diags
 

internal/terraform/node_resource_plan_instance.go

@@ -173,6 +173,7 @@ func (n *NodePlannableResourceInstance) managedResourceExecute(ctx EvalContext)
 	} else {
 		if instanceRefreshState != nil {
 			instanceRefreshState.CreateBeforeDestroy = n.Config.Managed.CreateBeforeDestroy || n.ForceCreateBeforeDestroy
+			instanceRefreshState.PreventRemoval = n.Config.Managed.PreventRemoval
 		}
 	}