terraform/internal/states/statemgr/testing.go
Martin Atkins b0b8d4aa6f states: Only track root module output values
For a very long time we've had an annoying discrepancy between the
in-memory state model and our state snapshot format where the in-memory
format stores output values for all modules whereas the snapshot format
only tracks the root module output values because those are all we
actually need to preserve between runs.

That design wart was a result of us using the state both as an internal
and an external artifact, due to having nowhere else to store the
transient values of non-root module output values while Terraform Core
does its work.

We now have namedvals.State to internally track all of the throwaway
results from named values that don't need to persist between runs, so now
we'll use that for our internal work instead and reserve the states.State
model only for the data that we will preserve between runs in state
snapshots.

The namedvals internal model isn't really designed to support enumerating
all of the output values for a particular module call, but our expression
evaluator currently depends on being able to do that and so we have a
temporary inefficient implementation of that which just scans the entire
table of values as a stopgap just to avoid this commit growing even larger
than it already is. In a future commit we'll rework the evaluator to
support the PartialEval mode and at the same time move the responsiblity
for enumerating all of the output values into the evaluator itself, since
it should be able to determine what it's expecting by analyzing the
configuration rather than just by trusting that earlier evaluation has
completed correctly.

Because our legacy state string serialization previously included output
values for all modules, some of our context tests were accidentally
depending on the implementation detail of how those got stored internally.
Those tests are updated here to test only the data that is a real part
of Terraform Core's result, by ensuring that the relevant data appears
somewhere either in a root output value or in a resource attribute.
2023-12-07 09:56:36 -08:00

177 lines
5.3 KiB
Go

// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1
package statemgr
import (
"reflect"
"testing"
"github.com/davecgh/go-spew/spew"
"github.com/zclconf/go-cty/cty"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/states"
"github.com/hashicorp/terraform/internal/states/statefile"
)
// TestFull is a helper for testing full state manager implementations. It
// expects that the given implementation is pre-loaded with a snapshot of the
// result from TestFullInitialState.
//
// If the given state manager also implements PersistentMeta, this function
// will test that the snapshot metadata changes as expected between calls
// to the methods of Persistent.
func TestFull(t *testing.T, s Full) {
t.Helper()
if err := s.RefreshState(); err != nil {
t.Fatalf("err: %s", err)
}
// Check that the initial state is correct.
// These do have different Lineages, but we will replace current below.
initial := TestFullInitialState()
if state := s.State(); !state.Equal(initial) {
t.Fatalf("state does not match expected initial state\n\ngot:\n%s\nwant:\n%s", spew.Sdump(state), spew.Sdump(initial))
}
var initialMeta SnapshotMeta
if sm, ok := s.(PersistentMeta); ok {
initialMeta = sm.StateSnapshotMeta()
}
// Now we've proven that the state we're starting with is an initial
// state, we'll complete our work here with that state, since otherwise
// further writes would violate the invariant that we only try to write
// states that share the same lineage as what was initially written.
current := s.State()
// Write a new state and verify that we have it
current.SetOutputValue(
addrs.OutputValue{Name: "bar"}.Absolute(addrs.RootModuleInstance),
cty.StringVal("baz"), false,
)
if err := s.WriteState(current); err != nil {
t.Fatalf("err: %s", err)
}
if actual := s.State(); !actual.Equal(current) {
t.Fatalf("bad:\n%#v\n\n%#v", actual, current)
}
// Test persistence
if err := s.PersistState(nil); err != nil {
t.Fatalf("err: %s", err)
}
// Refresh if we got it
if err := s.RefreshState(); err != nil {
t.Fatalf("err: %s", err)
}
var newMeta SnapshotMeta
if sm, ok := s.(PersistentMeta); ok {
newMeta = sm.StateSnapshotMeta()
if got, want := newMeta.Lineage, initialMeta.Lineage; got != want {
t.Errorf("Lineage changed from %q to %q", want, got)
}
if after, before := newMeta.Serial, initialMeta.Serial; after == before {
t.Errorf("Serial didn't change from %d after new module added", before)
}
}
// Same serial
serial := newMeta.Serial
if err := s.WriteState(current); err != nil {
t.Fatalf("err: %s", err)
}
if err := s.PersistState(nil); err != nil {
t.Fatalf("err: %s", err)
}
if sm, ok := s.(PersistentMeta); ok {
newMeta = sm.StateSnapshotMeta()
if newMeta.Serial != serial {
t.Fatalf("serial changed after persisting with no changes: got %d, want %d", newMeta.Serial, serial)
}
}
if sm, ok := s.(PersistentMeta); ok {
newMeta = sm.StateSnapshotMeta()
}
// Change the serial
current = current.DeepCopy()
current.SetOutputValue(
addrs.OutputValue{Name: "serialCheck"}.Absolute(addrs.RootModuleInstance),
cty.StringVal("true"), false,
)
if err := s.WriteState(current); err != nil {
t.Fatalf("err: %s", err)
}
if err := s.PersistState(nil); err != nil {
t.Fatalf("err: %s", err)
}
if sm, ok := s.(PersistentMeta); ok {
oldMeta := newMeta
newMeta = sm.StateSnapshotMeta()
if newMeta.Serial <= serial {
t.Fatalf("serial incorrect after persisting with changes: got %d, want > %d", newMeta.Serial, serial)
}
if newMeta.TerraformVersion != oldMeta.TerraformVersion {
t.Fatalf("TFVersion changed from %s to %s", oldMeta.TerraformVersion, newMeta.TerraformVersion)
}
// verify that Lineage doesn't change along with Serial, or during copying.
if newMeta.Lineage != oldMeta.Lineage {
t.Fatalf("Lineage changed from %q to %q", oldMeta.Lineage, newMeta.Lineage)
}
}
// Check that State() returns a copy by modifying the copy and comparing
// to the current state.
stateCopy := s.State()
stateCopy.EnsureModule(addrs.RootModuleInstance.Child("another", addrs.NoKey))
if reflect.DeepEqual(stateCopy, s.State()) {
t.Fatal("State() should return a copy")
}
// our current expected state should also marshal identically to the persisted state
if !statefile.StatesMarshalEqual(current, s.State()) {
t.Fatalf("Persisted state altered unexpectedly.\n\ngot:\n%s\nwant:\n%s", spew.Sdump(s.State()), spew.Sdump(current))
}
}
// TestFullInitialState is a state that should be snapshotted into a
// full state manager before passing it into TestFull.
func TestFullInitialState() *states.State {
state := states.NewState()
childMod := state.EnsureModule(addrs.RootModuleInstance.Child("child", addrs.NoKey))
rAddr := addrs.Resource{
Mode: addrs.ManagedResourceMode,
Type: "null_resource",
Name: "foo",
}
providerAddr := addrs.AbsProviderConfig{
Provider: addrs.NewDefaultProvider(rAddr.ImpliedProvider()),
Module: addrs.RootModule,
}
childMod.SetResourceProvider(rAddr, providerAddr)
state.SetOutputValue(
addrs.OutputValue{Name: "sensitive_output"}.Absolute(addrs.RootModuleInstance),
cty.StringVal("it's a secret"), true,
)
state.SetOutputValue(
addrs.OutputValue{Name: "nonsensitive_output"}.Absolute(addrs.RootModuleInstance),
cty.StringVal("hello, world!"), false,
)
return state
}