From ff2de9c818cba7e5031d4d316ea58396005d28d0 Mon Sep 17 00:00:00 2001 From: Martin Atkins Date: Tue, 16 Apr 2019 16:46:26 -0700 Subject: [PATCH] core: Keep old value on error even for delete When an operation fails, providers may return a null new value rather than returning a partial state. In that case, we'd prefer to keep the old value so that we stand the best chance of being able to retry on a subsequent run. Previously we were making an exception for the delete action, allowing the result of that to be null even when an error is returned. In practice that was a bad idea because it would cause Terraform to lose track of the object even though it might not actually have been deleted. Now we'll retain the old object even in the delete case. Providers can still return partial new objects if they were able to partially complete a delete operation, in which case we'll discard what we had before, but if the result is null with errors then we'll assume the delete failed entirely and so just keep the old state as-is, giving us the opportunity to refresh it on the next run to see if anything actually happened after all. (This also includes a new resource in the test provider which isn't used by the patch but was useful for some manual UX testing here, so I thought I'd include it in case it's similarly useful in future, given how simple its implementation is.) --- builtin/providers/test/provider.go | 1 + .../providers/test/resource_undeletable.go | 30 ++++++++ terraform/context_apply_test.go | 74 +++++++++++++++++++ terraform/eval_apply.go | 10 +-- 4 files changed, 110 insertions(+), 5 deletions(-) create mode 100644 builtin/providers/test/resource_undeletable.go diff --git a/builtin/providers/test/provider.go b/builtin/providers/test/provider.go index 31defa518..9d4dc94be 100644 --- a/builtin/providers/test/provider.go +++ b/builtin/providers/test/provider.go @@ -36,6 +36,7 @@ func Provider() terraform.ResourceProvider { "test_resource_computed_set": testResourceComputedSet(), "test_resource_config_mode": testResourceConfigMode(), "test_resource_nested_id": testResourceNestedId(), + "test_undeleteable": testResourceUndeleteable(), }, DataSourcesMap: map[string]*schema.Resource{ "test_data_source": testDataSource(), diff --git a/builtin/providers/test/resource_undeletable.go b/builtin/providers/test/resource_undeletable.go new file mode 100644 index 000000000..e5c9bb3b0 --- /dev/null +++ b/builtin/providers/test/resource_undeletable.go @@ -0,0 +1,30 @@ +package test + +import ( + "fmt" + + "github.com/hashicorp/terraform/helper/schema" +) + +func testResourceUndeleteable() *schema.Resource { + return &schema.Resource{ + Create: testResourceUndeleteableCreate, + Read: testResourceUndeleteableRead, + Delete: testResourceUndeleteableDelete, + + Schema: map[string]*schema.Schema{}, + } +} + +func testResourceUndeleteableCreate(d *schema.ResourceData, meta interface{}) error { + d.SetId("placeholder") + return testResourceUndeleteableRead(d, meta) +} + +func testResourceUndeleteableRead(d *schema.ResourceData, meta interface{}) error { + return nil +} + +func testResourceUndeleteableDelete(d *schema.ResourceData, meta interface{}) error { + return fmt.Errorf("test_undeleteable always fails deletion (use terraform state rm if you really want to delete it)") +} diff --git a/terraform/context_apply_test.go b/terraform/context_apply_test.go index 72b5ead79..4c71dbdd9 100644 --- a/terraform/context_apply_test.go +++ b/terraform/context_apply_test.go @@ -7097,6 +7097,80 @@ func TestContext2Apply_error(t *testing.T) { } } +func TestContext2Apply_errorDestroy(t *testing.T) { + m := testModule(t, "empty") + p := testProvider("test") + + p.GetSchemaReturn = &ProviderSchema{ + ResourceTypes: map[string]*configschema.Block{ + "test_thing": { + Attributes: map[string]*configschema.Attribute{ + "id": {Type: cty.String, Optional: true}, + }, + }, + }, + } + p.PlanResourceChangeFn = func(req providers.PlanResourceChangeRequest) providers.PlanResourceChangeResponse { + // Should actually be called for this test, because Terraform Core + // constructs the plan for a destroy operation itself. + return providers.PlanResourceChangeResponse{ + PlannedState: req.ProposedNewState, + } + } + p.ApplyResourceChangeFn = func(req providers.ApplyResourceChangeRequest) providers.ApplyResourceChangeResponse { + // The apply (in this case, a destroy) always fails, so we can verify + // that the object stays in the state after a destroy fails even though + // we aren't returning a new state object here. + return providers.ApplyResourceChangeResponse{ + Diagnostics: tfdiags.Diagnostics(nil).Append(fmt.Errorf("failed")), + } + } + + ctx := testContext2(t, &ContextOpts{ + Config: m, + State: states.BuildState(func(ss *states.SyncState) { + ss.SetResourceInstanceCurrent( + addrs.Resource{ + Mode: addrs.ManagedResourceMode, + Type: "test_thing", + Name: "foo", + }.Instance(addrs.NoKey).Absolute(addrs.RootModuleInstance), + &states.ResourceInstanceObjectSrc{ + Status: states.ObjectReady, + AttrsJSON: []byte(`{"id":"baz"}`), + }, + addrs.ProviderConfig{ + Type: "test", + }.Absolute(addrs.RootModuleInstance), + ) + }), + ProviderResolver: providers.ResolverFixed( + map[string]providers.Factory{ + "test": testProviderFuncFixed(p), + }, + ), + }) + + if _, diags := ctx.Plan(); diags.HasErrors() { + t.Fatalf("plan errors: %s", diags.Err()) + } + + state, diags := ctx.Apply() + if diags == nil { + t.Fatal("should have error") + } + + actual := strings.TrimSpace(state.String()) + expected := strings.TrimSpace(` +test_thing.foo: + ID = baz + provider = provider.test +`) // test_thing.foo is still here, even though provider returned no new state along with its error + if actual != expected { + t.Fatalf("expected:\n%s\n\ngot:\n%s", expected, actual) + } +} + func TestContext2Apply_errorCreateInvalidNew(t *testing.T) { m := testModule(t, "apply-error") diff --git a/terraform/eval_apply.go b/terraform/eval_apply.go index 1d766cda8..09313f7fc 100644 --- a/terraform/eval_apply.go +++ b/terraform/eval_apply.go @@ -247,11 +247,11 @@ func (n *EvalApply) Eval(ctx EvalContext) (interface{}, error) { } // Sometimes providers return a null value when an operation fails for some - // reason, but for any action other than delete we'd rather keep the prior - // state so that the error can be corrected on a subsequent run. We must - // only do this for null new value though, or else we may discard partial - // updates the provider was able to complete. - if change.Action != plans.Delete && diags.HasErrors() && newVal.IsNull() { + // reason, but we'd rather keep the prior state so that the error can be + // corrected on a subsequent run. We must only do this for null new value + // though, or else we may discard partial updates the provider was able to + // complete. + if diags.HasErrors() && newVal.IsNull() { // Otherwise, we'll continue but using the prior state as the new value, // making this effectively a no-op. If the item really _has_ been // deleted then our next refresh will detect that and fix it up.