opentofu/terraform/transform_destroy_edge_test.go
Martin Atkins 61baceb308 core: Skip edges between resource instances in different module instances
Our reference transformer analyses and our destroy transformer analyses
are built around static (not-yet-expanded) addresses so that they can
correctly handle mixtures of expanded and not-yet-expanded objects in the
same graph.

However, this characteristic also makes them unnecessarily conservative
in their handling of references between resources within different
instances of the same module: we know they can never interact with each
other in practice because the dependencies for all instances of a module
are the same and so one instance cannot possibly depend on another.

As a compromise then, here we introduce a new helper function that can
recognize when a proposed edge is between two resource instances that
belong to different instances of the same module, and thus allow us to
skip actually creating those edges even though our imprecise analyses
believe them to be needed.

As well as significantly reducing the number of edges in situations where
multi-instance resources appear inside multi-instance modules, this also
fixes some potential cycles in situations where a single plan includes
both destroying an instance of a module and creating a new instance of the
same module: the dependencies between the objects in the instance being
destroyed and the objects in the instance being created can, if allowed
to connect, cause Terraform to believe that the create and the destroy
both depend on one another even though there is no need for that to be
true in practice.

This involves a very specialized helper function to encode the situation
where this exception applies. This function has an ugly name to reflect
how specialized it is; it's not intended to be of any use outside of these
three situations in particular.
2020-07-17 08:40:13 -07:00

303 lines
9.7 KiB
Go

package terraform
import (
"fmt"
"strings"
"testing"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/states"
)
func TestDestroyEdgeTransformer_basic(t *testing.T) {
g := Graph{Path: addrs.RootModuleInstance}
g.Add(testDestroyNode("test_object.A"))
g.Add(testDestroyNode("test_object.B"))
state := states.NewState()
root := state.EnsureModule(addrs.RootModuleInstance)
root.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.A").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"A"}`),
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
root.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.B").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"B","test_string":"x"}`),
Dependencies: []addrs.ConfigResource{mustResourceAddr("test_object.A")},
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
if err := (&AttachStateTransformer{State: state}).Transform(&g); err != nil {
t.Fatal(err)
}
tf := &DestroyEdgeTransformer{
Config: testModule(t, "transform-destroy-edge-basic"),
Schemas: simpleTestSchemas(),
}
if err := tf.Transform(&g); err != nil {
t.Fatalf("err: %s", err)
}
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(testTransformDestroyEdgeBasicStr)
if actual != expected {
t.Fatalf("wrong result\n\ngot:\n%s\n\nwant:\n%s", actual, expected)
}
}
func TestDestroyEdgeTransformer_multi(t *testing.T) {
g := Graph{Path: addrs.RootModuleInstance}
g.Add(testDestroyNode("test_object.A"))
g.Add(testDestroyNode("test_object.B"))
g.Add(testDestroyNode("test_object.C"))
state := states.NewState()
root := state.EnsureModule(addrs.RootModuleInstance)
root.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.A").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"A"}`),
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
root.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.B").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"B","test_string":"x"}`),
Dependencies: []addrs.ConfigResource{mustResourceAddr("test_object.A")},
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
root.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.C").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"C","test_string":"x"}`),
Dependencies: []addrs.ConfigResource{
mustResourceAddr("test_object.A"),
mustResourceAddr("test_object.B"),
},
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
if err := (&AttachStateTransformer{State: state}).Transform(&g); err != nil {
t.Fatal(err)
}
tf := &DestroyEdgeTransformer{
Config: testModule(t, "transform-destroy-edge-multi"),
Schemas: simpleTestSchemas(),
}
if err := tf.Transform(&g); err != nil {
t.Fatalf("err: %s", err)
}
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(testTransformDestroyEdgeMultiStr)
if actual != expected {
t.Fatalf("wrong result\n\ngot:\n%s\n\nwant:\n%s", actual, expected)
}
}
func TestDestroyEdgeTransformer_selfRef(t *testing.T) {
g := Graph{Path: addrs.RootModuleInstance}
g.Add(testDestroyNode("test_object.A"))
tf := &DestroyEdgeTransformer{
Config: testModule(t, "transform-destroy-edge-self-ref"),
Schemas: simpleTestSchemas(),
}
if err := tf.Transform(&g); err != nil {
t.Fatalf("err: %s", err)
}
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(testTransformDestroyEdgeSelfRefStr)
if actual != expected {
t.Fatalf("wrong result\n\ngot:\n%s\n\nwant:\n%s", actual, expected)
}
}
func TestDestroyEdgeTransformer_module(t *testing.T) {
g := Graph{Path: addrs.RootModuleInstance}
g.Add(testDestroyNode("module.child.test_object.b"))
g.Add(testDestroyNode("test_object.a"))
state := states.NewState()
root := state.EnsureModule(addrs.RootModuleInstance)
child := state.EnsureModule(addrs.RootModuleInstance.Child("child", addrs.NoKey))
root.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.a").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"a"}`),
Dependencies: []addrs.ConfigResource{mustResourceAddr("module.child.test_object.b")},
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
child.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.b").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"b","test_string":"x"}`),
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
if err := (&AttachStateTransformer{State: state}).Transform(&g); err != nil {
t.Fatal(err)
}
tf := &DestroyEdgeTransformer{
Config: testModule(t, "transform-destroy-edge-module"),
Schemas: simpleTestSchemas(),
}
if err := tf.Transform(&g); err != nil {
t.Fatalf("err: %s", err)
}
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(testTransformDestroyEdgeModuleStr)
if actual != expected {
t.Fatalf("wrong result\n\ngot:\n%s\n\nwant:\n%s", actual, expected)
}
}
func TestDestroyEdgeTransformer_moduleOnly(t *testing.T) {
g := Graph{Path: addrs.RootModuleInstance}
state := states.NewState()
for moduleIdx := 0; moduleIdx < 2; moduleIdx++ {
g.Add(testDestroyNode(fmt.Sprintf("module.child[%d].test_object.a", moduleIdx)))
g.Add(testDestroyNode(fmt.Sprintf("module.child[%d].test_object.b", moduleIdx)))
g.Add(testDestroyNode(fmt.Sprintf("module.child[%d].test_object.c", moduleIdx)))
child := state.EnsureModule(addrs.RootModuleInstance.Child("child", addrs.IntKey(moduleIdx)))
child.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.a").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"a"}`),
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
child.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.b").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"b","test_string":"x"}`),
Dependencies: []addrs.ConfigResource{
mustResourceAddr("module.child.test_object.a"),
},
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
child.SetResourceInstanceCurrent(
mustResourceInstanceAddr("test_object.c").Resource,
&states.ResourceInstanceObjectSrc{
Status: states.ObjectReady,
AttrsJSON: []byte(`{"id":"c","test_string":"x"}`),
Dependencies: []addrs.ConfigResource{
mustResourceAddr("module.child.test_object.a"),
mustResourceAddr("module.child.test_object.b"),
},
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
}
if err := (&AttachStateTransformer{State: state}).Transform(&g); err != nil {
t.Fatal(err)
}
tf := &DestroyEdgeTransformer{
Config: testModule(t, "transform-destroy-edge-module-only"),
Schemas: simpleTestSchemas(),
}
if err := tf.Transform(&g); err != nil {
t.Fatalf("err: %s", err)
}
// The analyses done in the destroy edge transformer are between
// not-yet-expanded objects, which is conservative and so it will generate
// edges that aren't strictly necessary. As a special case we filter out
// any edges that are between resources instances that are in different
// instances of the same module, because those edges are never needed
// (one instance of a module cannot depend on another instance of the
// same module) and including them can, in complex cases, cause cycles due
// to unnecessary interactions between destroyed and created module
// instances in the same plan.
//
// Therefore below we expect to see the dependencies within each instance
// of module.child reflected, but we should not see any dependencies
// _between_ instances of module.child.
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(`
module.child[0].test_object.a (destroy)
module.child[0].test_object.b (destroy)
module.child[0].test_object.c (destroy)
module.child[0].test_object.b (destroy)
module.child[0].test_object.c (destroy)
module.child[0].test_object.c (destroy)
module.child[1].test_object.a (destroy)
module.child[1].test_object.b (destroy)
module.child[1].test_object.c (destroy)
module.child[1].test_object.b (destroy)
module.child[1].test_object.c (destroy)
module.child[1].test_object.c (destroy)
`)
if actual != expected {
t.Fatalf("wrong result\n\ngot:\n%s\n\nwant:\n%s", actual, expected)
}
}
func testDestroyNode(addrString string) GraphNodeDestroyer {
instAddr := mustResourceInstanceAddr(addrString)
inst := NewNodeAbstractResourceInstance(instAddr)
return &NodeDestroyResourceInstance{NodeAbstractResourceInstance: inst}
}
const testTransformDestroyEdgeBasicStr = `
test_object.A (destroy)
test_object.B (destroy)
test_object.B (destroy)
`
const testTransformDestroyEdgeCreatorStr = `
test_object.A
test_object.A (destroy)
test_object.A (destroy)
test_object.B (destroy)
test_object.B (destroy)
`
const testTransformDestroyEdgeMultiStr = `
test_object.A (destroy)
test_object.B (destroy)
test_object.C (destroy)
test_object.B (destroy)
test_object.C (destroy)
test_object.C (destroy)
`
const testTransformDestroyEdgeSelfRefStr = `
test_object.A (destroy)
`
const testTransformDestroyEdgeModuleStr = `
module.child.test_object.b (destroy)
test_object.a (destroy)
test_object.a (destroy)
`