opentofu/internal/terraform/node_resource_destroy.go
Martin Atkins 5573868cd0 core: Check pre- and postconditions for resources and output values
If the configuration contains preconditions and/or postconditions for any
objects, we'll check them during evaluation of those objects and generate
errors if any do not pass.

The handling of post-conditions is particularly interesting here because
we intentionally evaluate them _after_ we've committed our record of the
resulting side-effects to the state/plan, with the intent that future
plans against the same object will keep failing until the problem is
addressed either by changing the object so it would pass the precondition
or changing the precondition to accept the current object. That then
avoids the need for us to proactively taint managed resources whose
postconditions fail, as we would for provisioner failures: instead, we can
leave the resolution approach up to the user to decide.

Co-authored-by: Alisdair McDiarmid <alisdair@users.noreply.github.com>
2022-01-31 14:02:53 -05:00

234 lines
7.3 KiB
Go

package terraform
import (
"fmt"
"log"
"github.com/hashicorp/terraform/internal/plans"
"github.com/hashicorp/terraform/internal/tfdiags"
"github.com/hashicorp/terraform/internal/addrs"
"github.com/hashicorp/terraform/internal/configs"
"github.com/hashicorp/terraform/internal/states"
)
// NodeDestroyResourceInstance represents a resource instance that is to be
// destroyed.
type NodeDestroyResourceInstance struct {
*NodeAbstractResourceInstance
// If DeposedKey is set to anything other than states.NotDeposed then
// this node destroys a deposed object of the associated instance
// rather than its current object.
DeposedKey states.DeposedKey
}
var (
_ GraphNodeModuleInstance = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeConfigResource = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeResourceInstance = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeDestroyer = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeDestroyerCBD = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeReferenceable = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeReferencer = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeExecutable = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeProviderConsumer = (*NodeDestroyResourceInstance)(nil)
_ GraphNodeProvisionerConsumer = (*NodeDestroyResourceInstance)(nil)
)
func (n *NodeDestroyResourceInstance) Name() string {
if n.DeposedKey != states.NotDeposed {
return fmt.Sprintf("%s (destroy deposed %s)", n.ResourceInstanceAddr(), n.DeposedKey)
}
return n.ResourceInstanceAddr().String() + " (destroy)"
}
func (n *NodeDestroyResourceInstance) ProvidedBy() (addr addrs.ProviderConfig, exact bool) {
if n.Addr.Resource.Resource.Mode == addrs.DataResourceMode {
// indicate that this node does not require a configured provider
return nil, true
}
return n.NodeAbstractResourceInstance.ProvidedBy()
}
// GraphNodeDestroyer
func (n *NodeDestroyResourceInstance) DestroyAddr() *addrs.AbsResourceInstance {
addr := n.ResourceInstanceAddr()
return &addr
}
// GraphNodeDestroyerCBD
func (n *NodeDestroyResourceInstance) CreateBeforeDestroy() bool {
// State takes precedence during destroy.
// If the resource was removed, there is no config to check.
// If CBD was forced from descendent, it should be saved in the state
// already.
if s := n.instanceState; s != nil {
if s.Current != nil {
return s.Current.CreateBeforeDestroy
}
}
if n.Config != nil && n.Config.Managed != nil {
return n.Config.Managed.CreateBeforeDestroy
}
return false
}
// GraphNodeDestroyerCBD
func (n *NodeDestroyResourceInstance) ModifyCreateBeforeDestroy(v bool) error {
return nil
}
// GraphNodeReferenceable, overriding NodeAbstractResource
func (n *NodeDestroyResourceInstance) ReferenceableAddrs() []addrs.Referenceable {
normalAddrs := n.NodeAbstractResourceInstance.ReferenceableAddrs()
destroyAddrs := make([]addrs.Referenceable, len(normalAddrs))
phaseType := addrs.ResourceInstancePhaseDestroy
if n.CreateBeforeDestroy() {
phaseType = addrs.ResourceInstancePhaseDestroyCBD
}
for i, normalAddr := range normalAddrs {
switch ta := normalAddr.(type) {
case addrs.Resource:
destroyAddrs[i] = ta.Phase(phaseType)
case addrs.ResourceInstance:
destroyAddrs[i] = ta.Phase(phaseType)
default:
destroyAddrs[i] = normalAddr
}
}
return destroyAddrs
}
// GraphNodeReferencer, overriding NodeAbstractResource
func (n *NodeDestroyResourceInstance) References() []*addrs.Reference {
// If we have a config, then we need to include destroy-time dependencies
if c := n.Config; c != nil && c.Managed != nil {
var result []*addrs.Reference
// We include conn info and config for destroy time provisioners
// as dependencies that we have.
for _, p := range c.Managed.Provisioners {
schema := n.ProvisionerSchemas[p.Type]
if p.When == configs.ProvisionerWhenDestroy {
if p.Connection != nil {
result = append(result, ReferencesFromConfig(p.Connection.Config, connectionBlockSupersetSchema)...)
}
result = append(result, ReferencesFromConfig(p.Config, schema)...)
}
}
return result
}
return nil
}
// GraphNodeExecutable
func (n *NodeDestroyResourceInstance) Execute(ctx EvalContext, op walkOperation) (diags tfdiags.Diagnostics) {
addr := n.ResourceInstanceAddr()
// Eval info is different depending on what kind of resource this is
switch addr.Resource.Resource.Mode {
case addrs.ManagedResourceMode:
return n.managedResourceExecute(ctx)
case addrs.DataResourceMode:
return n.dataResourceExecute(ctx)
default:
panic(fmt.Errorf("unsupported resource mode %s", n.Config.Mode))
}
}
func (n *NodeDestroyResourceInstance) managedResourceExecute(ctx EvalContext) (diags tfdiags.Diagnostics) {
addr := n.ResourceInstanceAddr()
// Get our state
is := n.instanceState
if is == nil {
log.Printf("[WARN] NodeDestroyResourceInstance for %s with no state", addr)
}
// These vars are updated through pointers at various stages below.
var changeApply *plans.ResourceInstanceChange
var state *states.ResourceInstanceObject
_, providerSchema, err := getProvider(ctx, n.ResolvedProvider)
diags = diags.Append(err)
if diags.HasErrors() {
return diags
}
changeApply, err = n.readDiff(ctx, providerSchema)
diags = diags.Append(err)
if changeApply == nil || diags.HasErrors() {
return diags
}
changeApply = reducePlan(addr.Resource, changeApply, true)
// reducePlan may have simplified our planned change
// into a NoOp if it does not require destroying.
if changeApply == nil || changeApply.Action == plans.NoOp {
return diags
}
state, readDiags := n.readResourceInstanceState(ctx, addr)
diags = diags.Append(readDiags)
if diags.HasErrors() {
return diags
}
// Exit early if the state object is null after reading the state
if state == nil || state.Value.IsNull() {
return diags
}
diags = diags.Append(n.preApplyHook(ctx, changeApply))
if diags.HasErrors() {
return diags
}
// Run destroy provisioners if not tainted
if state.Status != states.ObjectTainted {
applyProvisionersDiags := n.evalApplyProvisioners(ctx, state, false, configs.ProvisionerWhenDestroy)
diags = diags.Append(applyProvisionersDiags)
// keep the diags separate from the main set until we handle the cleanup
if diags.HasErrors() {
// If we have a provisioning error, then we just call
// the post-apply hook now.
diags = diags.Append(n.postApplyHook(ctx, state, diags.Err()))
return diags
}
}
// Managed resources need to be destroyed, while data sources
// are only removed from state.
// we pass a nil configuration to apply because we are destroying
s, _, d := n.apply(ctx, state, changeApply, nil, false)
state, diags = s, diags.Append(d)
// we don't return immediately here on error, so that the state can be
// finalized
err = n.writeResourceInstanceState(ctx, state, workingState)
if err != nil {
return diags.Append(err)
}
// create the err value for postApplyHook
diags = diags.Append(n.postApplyHook(ctx, state, diags.Err()))
diags = diags.Append(updateStateHook(ctx))
return diags
}
func (n *NodeDestroyResourceInstance) dataResourceExecute(ctx EvalContext) (diags tfdiags.Diagnostics) {
log.Printf("[TRACE] NodeDestroyResourceInstance: removing state object for %s", n.Addr)
ctx.State().SetResourceInstanceCurrent(n.Addr, nil, n.ResolvedProvider)
return diags.Append(updateStateHook(ctx))
}