Merge pull request #28165 from hashicorp/jbardin/destroy-update-dep

Destroy then update dependency ordering
This commit is contained in:
James Bardin 2021-03-23 11:04:55 -04:00 committed by GitHub
commit 0ebc71383b
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6 changed files with 185 additions and 17 deletions

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@ -114,6 +114,7 @@ digraph replacement {
}
a -> a_d;
a -> b_d [style=dotted];
b -> a_d [style=dotted];
b -> b_d;
}
@ -158,6 +159,28 @@ While the dependency edge from `B update` to `A destroy` isn't necessary in
these examples, it is shown here as an implementation detail which will be
mentioned later on.
A final example based on the replacement graph; starting with the above
configuration where `B` depends on `A`. The graph is reduced to an update of
`A` while only destroying `B`. The interesting feature here is the remaining
dependency of `A update` on `B destroy`. We can derive this ordering of
operations from the full replacement example above, by replacing `A create`
with `A update` and removing the unused nodes.
![Replace All](./images/destroy_then_update.png)
<!--
digraph destroy_then_update {
subgraph update {
rank=same;
a [label="A update"];
}
subgraph destroy {
rank=same;
b_d [label="B destroy"];
}
a -> b_d;
}
-->
## Create Before Destroy
Currently, the only user-controllable method for changing the ordering of

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@ -3,7 +3,9 @@ package terraform
import (
"errors"
"fmt"
"sync"
"testing"
"time"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/providers"
@ -177,3 +179,72 @@ output "data" {
t.Fatal(diags.Err())
}
}
func TestContext2Apply_destroyThenUpdate(t *testing.T) {
m := testModuleInline(t, map[string]string{
"main.tf": `
resource "test_instance" "a" {
value = "udpated"
}
`,
})
p := testProvider("test")
p.PlanResourceChangeFn = testDiffFn
var orderMu sync.Mutex
var order []string
p.ApplyResourceChangeFn = func(req providers.ApplyResourceChangeRequest) (resp providers.ApplyResourceChangeResponse) {
id := req.PriorState.GetAttr("id").AsString()
if id == "b" {
// slow down the b destroy, since a should wait for it
time.Sleep(100 * time.Millisecond)
}
orderMu.Lock()
order = append(order, id)
orderMu.Unlock()
resp.NewState = req.PlannedState
return resp
}
addrA := mustResourceInstanceAddr(`test_instance.a`)
addrB := mustResourceInstanceAddr(`test_instance.b`)
state := states.BuildState(func(s *states.SyncState) {
s.SetResourceInstanceCurrent(addrA, &states.ResourceInstanceObjectSrc{
AttrsJSON: []byte(`{"id":"a","value":"old","type":"test"}`),
Status: states.ObjectReady,
}, mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`))
// test_instance.b depended on test_instance.a, and therefor should be
// destroyed before any changes to test_instance.a
s.SetResourceInstanceCurrent(addrB, &states.ResourceInstanceObjectSrc{
AttrsJSON: []byte(`{"id":"b"}`),
Status: states.ObjectReady,
Dependencies: []addrs.ConfigResource{addrA.ContainingResource().Config()},
}, mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`))
})
ctx := testContext2(t, &ContextOpts{
Config: m,
State: state,
Providers: map[addrs.Provider]providers.Factory{
addrs.NewDefaultProvider("test"): testProviderFuncFixed(p),
},
})
if _, diags := ctx.Plan(); diags.HasErrors() {
t.Fatal(diags.Err())
}
_, diags := ctx.Apply()
if diags.HasErrors() {
t.Fatal(diags.Err())
}
if order[0] != "b" {
t.Fatalf("expected apply order [b, a], got: %v\n", order)
}
}

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@ -59,7 +59,7 @@ func (t *DestroyEdgeTransformer) Transform(g *Graph) error {
// Record the creators, which will need to depend on the destroyers if they
// are only being updated.
creators := make(map[string]GraphNodeCreator)
creators := make(map[string][]GraphNodeCreator)
// destroyersByResource records each destroyer by the ConfigResource
// address. We use this because dependencies are only referenced as
@ -83,8 +83,8 @@ func (t *DestroyEdgeTransformer) Transform(g *Graph) error {
resAddr := addr.ContainingResource().Config().String()
destroyersByResource[resAddr] = append(destroyersByResource[resAddr], n)
case GraphNodeCreator:
addr := n.CreateAddr()
creators[addr.String()] = n
addr := n.CreateAddr().ContainingResource().Config().String()
creators[addr] = append(creators[addr], n)
}
}
@ -111,12 +111,25 @@ func (t *DestroyEdgeTransformer) Transform(g *Graph) error {
log.Printf("[TRACE] DestroyEdgeTransformer: skipping %s => %s inter-module-instance dependency\n", dag.VertexName(desDep), dag.VertexName(des))
}
}
// We can have some create or update nodes which were
// dependents of the destroy node. If they have no destroyer
// themselves, make the connection directly from the creator.
for _, createDep := range creators[resAddr.String()] {
if !graphNodesAreResourceInstancesInDifferentInstancesOfSameModule(createDep, des) {
log.Printf("[DEBUG] DestroyEdgeTransformer: %s has stored dependency of %s\n", dag.VertexName(createDep), dag.VertexName(des))
g.Connect(dag.BasicEdge(createDep, des))
} else {
log.Printf("[TRACE] DestroyEdgeTransformer: skipping %s => %s inter-module-instance dependency\n", dag.VertexName(createDep), dag.VertexName(des))
}
}
}
}
}
// connect creators to any destroyers on which they may depend
for _, c := range creators {
for _, cs := range creators {
for _, c := range cs {
ri, ok := c.(GraphNodeResourceInstance)
if !ok {
continue
@ -133,6 +146,7 @@ func (t *DestroyEdgeTransformer) Transform(g *Graph) error {
}
}
}
}
// Go through and connect creators to destroyers. Going along with
// our example, this makes: A_d => A

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@ -260,14 +260,74 @@ module.child[1].test_object.c (destroy)
}
}
func TestDestroyEdgeTransformer_destroyThenUpdate(t *testing.T) {
g := Graph{Path: addrs.RootModuleInstance}
g.Add(testUpdateNode("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","test_string":"old"}`),
},
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{mustConfigResourceAddr("test_object.A")},
},
mustProviderConfig(`provider["registry.terraform.io/hashicorp/test"]`),
)
if err := (&AttachStateTransformer{State: state}).Transform(&g); err != nil {
t.Fatal(err)
}
m := testModuleInline(t, map[string]string{
"main.tf": `
resource "test_instance" "a" {
test_string = "udpated"
}
`,
})
tf := &DestroyEdgeTransformer{
Config: m,
Schemas: simpleTestSchemas(),
}
if err := tf.Transform(&g); err != nil {
t.Fatalf("err: %s", err)
}
expected := strings.TrimSpace(`
test_object.A
test_object.B (destroy)
test_object.B (destroy)
`)
actual := strings.TrimSpace(g.String())
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}
}
func testUpdateNode(addrString string) GraphNodeCreator {
instAddr := mustResourceInstanceAddr(addrString)
inst := NewNodeAbstractResourceInstance(instAddr)
return &NodeApplyableResourceInstance{NodeAbstractResourceInstance: inst}
}
const testTransformDestroyEdgeBasicStr = `
test_object.A (destroy)
test_object.B (destroy)