/
step_generator.go
1366 lines (1207 loc) 路 55.7 KB
/
step_generator.go
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// Copyright 2016-2018, Pulumi Corporation.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package deploy
import (
"strings"
"github.com/pkg/errors"
"github.com/pulumi/pulumi/sdk/go/common/apitype"
"github.com/pulumi/pulumi/pkg/resource/deploy/providers"
"github.com/pulumi/pulumi/pkg/resource/graph"
"github.com/pulumi/pulumi/sdk/go/common/diag"
"github.com/pulumi/pulumi/sdk/go/common/resource"
"github.com/pulumi/pulumi/sdk/go/common/resource/plugin"
"github.com/pulumi/pulumi/sdk/go/common/tokens"
"github.com/pulumi/pulumi/sdk/go/common/util/contract"
"github.com/pulumi/pulumi/sdk/go/common/util/logging"
"github.com/pulumi/pulumi/sdk/go/common/util/result"
)
// stepGenerator is responsible for turning resource events into steps that
// can be fed to the plan executor. It does this by consulting the plan
// and calculating the appropriate step action based on the requested goal
// state and the existing state of the world.
type stepGenerator struct {
plan *Plan // the plan to which this step generator belongs
opts Options // options for this step generator
updateTargetsOpt map[resource.URN]bool // the set of resources to update; resources not in this set will be same'd
replaceTargetsOpt map[resource.URN]bool // the set of resoures to replace
// signals that one or more errors have been reported to the user, and the plan should terminate
// in error. This primarily allows `preview` to aggregate many policy violation events and
// report them all at once.
sawError bool
urns map[resource.URN]bool // set of URNs discovered for this plan
reads map[resource.URN]bool // set of URNs read for this plan
deletes map[resource.URN]bool // set of URNs deleted in this plan
replaces map[resource.URN]bool // set of URNs replaced in this plan
updates map[resource.URN]bool // set of URNs updated in this plan
creates map[resource.URN]bool // set of URNs created in this plan
sames map[resource.URN]bool // set of URNs that were not changed in this plan
// set of URNs that would have been created, but were filtered out because the user didn't
// specify them with --target
skippedCreates map[resource.URN]bool
pendingDeletes map[*resource.State]bool // set of resources (not URNs!) that are pending deletion
providers map[resource.URN]*resource.State // URN map of providers that we have seen so far.
resourceGoals map[resource.URN]*resource.Goal // URN map of goals for ALL resources we have seen so far.
resourceStates map[resource.URN]*resource.State // URN map of state for ALL resources we have seen so far.
// a map from URN to a list of property keys that caused the replacement of a dependent resource during a
// delete-before-replace.
dependentReplaceKeys map[resource.URN][]resource.PropertyKey
// a map from old names (aliased URNs) to the new URN that aliased to them.
aliased map[resource.URN]resource.URN
}
func (sg *stepGenerator) isTargetedUpdate() bool {
return sg.updateTargetsOpt != nil || sg.replaceTargetsOpt != nil
}
func (sg *stepGenerator) isTargetedForUpdate(urn resource.URN) bool {
return sg.updateTargetsOpt == nil || sg.updateTargetsOpt[urn]
}
func (sg *stepGenerator) isTargetedReplace(urn resource.URN) bool {
return sg.replaceTargetsOpt != nil && sg.replaceTargetsOpt[urn]
}
func (sg *stepGenerator) Errored() bool {
return sg.sawError
}
// GenerateReadSteps is responsible for producing one or more steps required to service
// a ReadResourceEvent coming from the language host.
func (sg *stepGenerator) GenerateReadSteps(event ReadResourceEvent) ([]Step, result.Result) {
urn := sg.plan.generateURN(event.Parent(), event.Type(), event.Name())
newState := resource.NewState(event.Type(),
urn,
true, /*custom*/
false, /*delete*/
event.ID(),
event.Properties(),
make(resource.PropertyMap), /* outputs */
event.Parent(),
false, /*protect*/
true, /*external*/
event.Dependencies(),
nil, /* initErrors */
event.Provider(),
nil, /* propertyDependencies */
false, /* deleteBeforeCreate */
event.AdditionalSecretOutputs(),
nil, /* aliases */
nil, /* customTimeouts */
)
old, hasOld := sg.plan.Olds()[urn]
// If the snapshot has an old resource for this URN and it's not external, we're going
// to have to delete the old resource and conceptually replace it with the resource we
// are about to read.
//
// We accomplish this through the "read-replacement" step, which atomically reads a resource
// and marks the resource it is replacing as pending deletion.
//
// In the event that the new "read" resource's ID matches the existing resource,
// we do not need to delete the resource - we know exactly what resource we are going
// to get from the read.
//
// This operation is tentatively called "relinquish" - it semantically represents the
// release of a resource from the management of Pulumi.
if hasOld && !old.External && old.ID != event.ID() {
logging.V(7).Infof(
"stepGenerator.GenerateReadSteps(...): replacing existing resource %s, ids don't match", urn)
sg.replaces[urn] = true
return []Step{
NewReadReplacementStep(sg.plan, event, old, newState),
NewReplaceStep(sg.plan, old, newState, nil, nil, nil, true),
}, nil
}
if bool(logging.V(7)) && hasOld && old.ID == event.ID() {
logging.V(7).Infof("stepGenerator.GenerateReadSteps(...): recognized relinquish of resource %s", urn)
}
sg.reads[urn] = true
return []Step{
NewReadStep(sg.plan, event, old, newState),
}, nil
}
// GenerateSteps produces one or more steps required to achieve the goal state specified by the
// incoming RegisterResourceEvent.
//
// If the given resource is a custom resource, the step generator will invoke Diff and Check on the
// provider associated with that resource. If those fail, an error is returned.
func (sg *stepGenerator) GenerateSteps(event RegisterResourceEvent) ([]Step, result.Result) {
steps, res := sg.generateSteps(event)
if res != nil {
contract.Assert(len(steps) == 0)
return nil, res
}
if !sg.isTargetedUpdate() {
return steps, nil
}
// We got a set of steps to perfom during a targeted update. If any of the steps are not same steps and depend on
// creates we skipped because they were not in the --target list, issue an error that that the create was necessary
// and that the user must target the resource to create.
for _, step := range steps {
if step.Op() == OpSame || step.New() == nil {
continue
}
for _, urn := range step.New().Dependencies {
if sg.skippedCreates[urn] {
// Targets were specified, but didn't include this resource to create. And a
// resource we are producing a step for does depend on this created resource.
// Give a particular error in that case to let them know. Also mark that we're
// in an error state so that we eventually will error out of the entire
// application run.
d := diag.GetResourceWillBeCreatedButWasNotSpecifiedInTargetList(step.URN())
sg.plan.Diag().Errorf(d, step.URN(), urn)
sg.sawError = true
if !sg.plan.preview {
// In preview we keep going so that the user will hear about all the problems and can then
// fix up their command once (as opposed to adding a target, rerunning, adding a target,
// rerunning, etc. etc.).
//
// Doing a normal run. We should not proceed here at all. We don't want to create
// something the user didn't ask for.
return nil, result.Bail()
}
// Remove the resource from the list of skipped creates so that we do not issue duplicate diagnostics.
delete(sg.skippedCreates, urn)
}
}
}
return steps, nil
}
func (sg *stepGenerator) generateSteps(event RegisterResourceEvent) ([]Step, result.Result) {
var invalid bool // will be set to true if this object fails validation.
goal := event.Goal()
// Generate a URN for this new resource, confirm we haven't seen it before in this plan.
urn := sg.plan.generateURN(goal.Parent, goal.Type, goal.Name)
if sg.urns[urn] {
invalid = true
// TODO[pulumi/pulumi-framework#19]: improve this error message!
sg.plan.Diag().Errorf(diag.GetDuplicateResourceURNError(urn), urn)
}
sg.urns[urn] = true
// Check for an old resource so that we can figure out if this is a create, delete, etc., and/or
// to diff. We look up first by URN and then by any provided aliases. If it is found using an
// alias, record that alias so that we do not delete the aliased resource later.
var oldInputs resource.PropertyMap
var oldOutputs resource.PropertyMap
var old *resource.State
var hasOld bool
for _, urnOrAlias := range append([]resource.URN{urn}, goal.Aliases...) {
old, hasOld = sg.plan.Olds()[urnOrAlias]
if hasOld {
oldInputs = old.Inputs
oldOutputs = old.Outputs
if urnOrAlias != urn {
if previousAliasURN, alreadyAliased := sg.aliased[urnOrAlias]; alreadyAliased {
invalid = true
sg.plan.Diag().Errorf(diag.GetDuplicateResourceAliasError(urn), urnOrAlias, urn, previousAliasURN)
}
sg.aliased[urnOrAlias] = urn
}
break
}
}
// Create the desired inputs from the goal state
inputs := goal.Properties
if hasOld {
// Set inputs back to their old values (if any) for any "ignored" properties
processedInputs, res := processIgnoreChanges(inputs, oldInputs, goal.IgnoreChanges)
if res != nil {
return nil, res
}
inputs = processedInputs
}
// Produce a new state object that we'll build up as operations are performed. Ultimately, this is what will
// get serialized into the checkpoint file.
new := resource.NewState(goal.Type, urn, goal.Custom, false, "", inputs, nil, goal.Parent, goal.Protect, false,
goal.Dependencies, goal.InitErrors, goal.Provider, goal.PropertyDependencies, false,
goal.AdditionalSecretOutputs, goal.Aliases, &goal.CustomTimeouts)
// Mark the URN/resource as having been seen. So we can run analyzers on all resources seen, as well as
// lookup providers for calculating replacement of resources that use the provider.
sg.resourceGoals[urn] = goal
sg.resourceStates[urn] = new
if providers.IsProviderType(goal.Type) {
sg.providers[urn] = new
}
// Fetch the provider for this resource.
prov, res := sg.loadResourceProvider(urn, goal.Custom, goal.Provider, goal.Type)
if res != nil {
return nil, res
}
// We only allow unknown property values to be exposed to the provider if we are performing an update preview.
allowUnknowns := sg.plan.preview
// We may be re-creating this resource if it got deleted earlier in the execution of this plan.
_, recreating := sg.deletes[urn]
// We may be creating this resource if it previously existed in the snapshot as an External resource
wasExternal := hasOld && old.External
// If the goal contains an ID, this may be an import. An import occurs if there is no old resource or if the old
// resource's ID does not match the ID in the goal state.
isImport := goal.Custom && goal.ID != "" && (!hasOld || old.External || old.ID != goal.ID)
if isImport {
// Write the ID of the resource to import into the new state and return an ImportStep or an
// ImportReplacementStep
new.ID = goal.ID
if isReplace := hasOld && !recreating; isReplace {
return []Step{
NewImportReplacementStep(sg.plan, event, old, new, goal.IgnoreChanges),
NewReplaceStep(sg.plan, old, new, nil, nil, nil, true),
}, nil
}
return []Step{NewImportStep(sg.plan, event, new, goal.IgnoreChanges)}, nil
}
// Ensure the provider is okay with this resource and fetch the inputs to pass to subsequent methods.
var err error
if prov != nil {
var failures []plugin.CheckFailure
// If we are re-creating this resource because it was deleted earlier, the old inputs are now
// invalid (they got deleted) so don't consider them. Similarly, if the old resource was External,
// don't consider those inputs since Pulumi does not own them. Finally, if the resource has been
// targeted for replacement, ignore its old state.
if recreating || wasExternal || sg.isTargetedReplace(urn) {
inputs, failures, err = prov.Check(urn, nil, goal.Properties, allowUnknowns)
} else {
inputs, failures, err = prov.Check(urn, oldInputs, inputs, allowUnknowns)
}
if err != nil {
return nil, result.FromError(err)
} else if issueCheckErrors(sg.plan, new, urn, failures) {
invalid = true
}
new.Inputs = inputs
}
// Send the resource off to any Analyzers before being operated on.
analyzers := sg.plan.ctx.Host.ListAnalyzers()
for _, analyzer := range analyzers {
r := plugin.AnalyzerResource{
URN: new.URN,
Type: new.Type,
Name: new.URN.Name(),
Properties: inputs,
Options: plugin.AnalyzerResourceOptions{
Protect: new.Protect,
IgnoreChanges: goal.IgnoreChanges,
DeleteBeforeReplace: goal.DeleteBeforeReplace,
AdditionalSecretOutputs: new.AdditionalSecretOutputs,
Aliases: new.Aliases,
CustomTimeouts: new.CustomTimeouts,
},
}
providerResource := sg.getProviderResource(new.URN, new.Provider)
if providerResource != nil {
r.Provider = &plugin.AnalyzerProviderResource{
URN: providerResource.URN,
Type: providerResource.Type,
Name: providerResource.URN.Name(),
Properties: providerResource.Inputs,
}
}
diagnostics, err := analyzer.Analyze(r)
if err != nil {
return nil, result.FromError(err)
}
for _, d := range diagnostics {
if d.EnforcementLevel == apitype.Mandatory {
if !sg.plan.preview {
invalid = true
}
sg.sawError = true
}
// For now, we always use the URN we have here rather than a URN specified with the diagnostic.
sg.opts.Events.OnPolicyViolation(new.URN, d)
}
}
// If the resource isn't valid, don't proceed any further.
if invalid {
return nil, result.Bail()
}
// There are four cases we need to consider when figuring out what to do with this resource.
//
// Case 1: recreating
// In this case, we have seen a resource with this URN before and we have already issued a
// delete step for it. This happens when the engine has to delete a resource before it has
// enough information about whether that resource still exists. A concrete example is
// when a resource depends on a resource that is delete-before-replace: the engine must first
// delete the dependent resource before depending the DBR resource, but the engine can't know
// yet whether the dependent resource is being replaced or deleted.
//
// In this case, we are seeing the resource again after deleting it, so it must be a replacement.
//
// Logically, recreating implies hasOld, since in order to delete something it must have
// already existed.
contract.Assert(!recreating || hasOld)
if recreating {
logging.V(7).Infof("Planner decided to re-create replaced resource '%v' deleted due to dependent DBR", urn)
// Unmark this resource as deleted, we now know it's being replaced instead.
delete(sg.deletes, urn)
sg.replaces[urn] = true
keys := sg.dependentReplaceKeys[urn]
return []Step{
NewReplaceStep(sg.plan, old, new, nil, nil, nil, false),
NewCreateReplacementStep(sg.plan, event, old, new, keys, nil, nil, false),
}, nil
}
// Case 2: wasExternal
// In this case, the resource we are operating upon exists in the old snapshot, but it
// was "external" - Pulumi does not own its lifecycle. Conceptually, this operation is
// akin to "taking ownership" of a resource that we did not previously control.
//
// Since we are not allowed to manipulate the existing resource, we must create a resource
// to take its place. Since this is technically a replacement operation, we pend deletion of
// read until the end of the plan.
if wasExternal {
logging.V(7).Infof("Planner recognized '%s' as old external resource, creating instead", urn)
sg.creates[urn] = true
if err != nil {
return nil, result.FromError(err)
}
return []Step{
NewCreateReplacementStep(sg.plan, event, old, new, nil, nil, nil, true),
NewReplaceStep(sg.plan, old, new, nil, nil, nil, true),
}, nil
}
// Case 3: hasOld
// In this case, the resource we are operating upon now exists in the old snapshot.
// It must be an update or a replace. Which operation we do depends on the the specific change made to the
// resource's properties:
//
// - if the user has requested that only specific resources be updated, and this resource is
// not in that set, do no 'Diff' and just treat the resource as 'same' (i.e. unchanged).
//
// - If the resource's provider reference changed, the resource must be replaced. This behavior is founded upon
// the assumption that providers are recreated iff their configuration changed in such a way that they are no
// longer able to manage existing resources.
//
// - Otherwise, we invoke the resource's provider's `Diff` method. If this method indicates that the resource must
// be replaced, we do so. If it does not, we update the resource in place.
if hasOld {
contract.Assert(old != nil)
// If the user requested only specific resources to update, and this resource was not in
// that set, then do nothin but create a SameStep for it.
if !sg.isTargetedForUpdate(urn) {
logging.V(7).Infof(
"Planner decided not to update '%v' due to not being in target group (same) (inputs=%v)", urn, new.Inputs)
} else {
updateSteps, res := sg.generateStepsFromDiff(
event, urn, old, new, oldInputs, oldOutputs, inputs, prov, goal)
if res != nil {
return nil, res
}
if len(updateSteps) > 0 {
// 'Diff' produced update steps. We're done at this point.
return updateSteps, nil
}
// Diff didn't produce any steps for this resource. Fall through and indicate that it
// is same/unchanged.
logging.V(7).Infof("Planner decided not to update '%v' after diff (same) (inputs=%v)", urn, new.Inputs)
}
// No need to update anything, the properties didn't change.
sg.sames[urn] = true
return []Step{NewSameStep(sg.plan, event, old, new)}, nil
}
// Case 4: Not Case 1, 2, or 3
// If a resource isn't being recreated and it's not being updated or replaced,
// it's just being created.
// We're in the create stage now. In a normal run just issue a 'create step'. If, however, the
// user is doing a run with `--target`s, then we need to operate specially here.
//
// 1. If the user did include this resource urn in the --target list, then we can proceed
// normally and issue a create step for this.
//
// 2. However, if they did not include the resource in the --target list, then we want to flat
// out ignore it (just like we ignore updates to resource not in the --target list). This has
// interesting implications though. Specifically, what to do if a prop from this resource is
// then actually needed by a property we *are* doing a targeted create/update for.
//
// In that case, we want to error to force the user to be explicit about wanting this resource
// to be created. However, we can't issue the error until later on when the resource is
// referenced. So, to support this we create a special "same" step here for this resource. That
// "same" step has a bit on it letting us know that it is for this case. If we then later see a
// resource that depends on this resource, we will issue an error letting the user know.
//
// We will also not record this non-created resource into the checkpoint as it doesn't actually
// exist.
if !sg.isTargetedForUpdate(urn) &&
!providers.IsProviderType(goal.Type) {
sg.sames[urn] = true
sg.skippedCreates[urn] = true
return []Step{NewSkippedCreateStep(sg.plan, event, new)}, nil
}
sg.creates[urn] = true
logging.V(7).Infof("Planner decided to create '%v' (inputs=%v)", urn, new.Inputs)
return []Step{NewCreateStep(sg.plan, event, new)}, nil
}
func (sg *stepGenerator) generateStepsFromDiff(
event RegisterResourceEvent, urn resource.URN, old, new *resource.State,
oldInputs, oldOutputs, inputs resource.PropertyMap,
prov plugin.Provider, goal *resource.Goal) ([]Step, result.Result) {
// We only allow unknown property values to be exposed to the provider if we are performing an update preview.
allowUnknowns := sg.plan.preview
diff, err := sg.diff(urn, old, new, oldInputs, oldOutputs, inputs, prov, allowUnknowns, goal.IgnoreChanges)
// If the plugin indicated that the diff is unavailable, assume that the resource will be updated and
// report the message contained in the error.
if _, ok := err.(plugin.DiffUnavailableError); ok {
diff = plugin.DiffResult{Changes: plugin.DiffSome}
sg.plan.ctx.Diag.Warningf(diag.RawMessage(urn, err.Error()))
} else if err != nil {
return nil, result.FromError(err)
}
// Ensure that we received a sensible response.
if diff.Changes != plugin.DiffNone && diff.Changes != plugin.DiffSome {
return nil, result.Errorf(
"unrecognized diff state for %s: %d", urn, diff.Changes)
}
// If there were changes, check for a replacement vs. an in-place update.
if diff.Changes == plugin.DiffSome {
if diff.Replace() {
// If the goal state specified an ID, issue an error: the replacement will change the ID, and is
// therefore incompatible with the goal state.
if goal.ID != "" {
const message = "previously-imported resources that still specify an ID may not be replaced; " +
"please remove the `import` declaration from your program"
if sg.plan.preview {
sg.plan.ctx.Diag.Warningf(diag.StreamMessage(urn, message, 0))
} else {
return nil, result.Errorf(message)
}
}
sg.replaces[urn] = true
// If we are going to perform a replacement, we need to recompute the default values. The above logic
// had assumed that we were going to carry them over from the old resource, which is no longer true.
//
// Note that if we're performing a targeted replace, we already have the correct inputs.
if prov != nil && !sg.isTargetedReplace(urn) {
var failures []plugin.CheckFailure
inputs, failures, err = prov.Check(urn, nil, goal.Properties, allowUnknowns)
if err != nil {
return nil, result.FromError(err)
} else if issueCheckErrors(sg.plan, new, urn, failures) {
return nil, result.Bail()
}
new.Inputs = inputs
}
if logging.V(7) {
logging.V(7).Infof("Planner decided to replace '%v' (oldprops=%v inputs=%v)",
urn, oldInputs, new.Inputs)
}
// We have two approaches to performing replacements:
//
// * CreateBeforeDelete: the default mode first creates a new instance of the resource, then
// updates all dependent resources to point to the new one, and finally after all of that,
// deletes the old resource. This ensures minimal downtime.
//
// * DeleteBeforeCreate: this mode can be used for resources that cannot be tolerate having
// side-by-side old and new instances alive at once. This first deletes the resource and
// then creates the new one. This may result in downtime, so is less preferred. Note that
// until pulumi/pulumi#624 is resolved, we cannot safely perform this operation on resources
// that have dependent resources (we try to delete the resource while they refer to it).
//
// The provider is responsible for requesting which of these two modes to use. The user can override
// the provider's decision by setting the `deleteBeforeReplace` field of `ResourceOptions` to either
// `true` or `false`.
deleteBeforeReplace := diff.DeleteBeforeReplace
if goal.DeleteBeforeReplace != nil {
deleteBeforeReplace = *goal.DeleteBeforeReplace
}
if deleteBeforeReplace {
logging.V(7).Infof("Planner decided to delete-before-replacement for resource '%v'", urn)
contract.Assert(sg.plan.depGraph != nil)
// DeleteBeforeCreate implies that we must immediately delete the resource. For correctness,
// we must also eagerly delete all resources that depend directly or indirectly on the resource
// being replaced and would be replaced by a change to the relevant dependency.
//
// To do this, we'll utilize the dependency information contained in the snapshot if it is
// trustworthy, which is interpreted by the DependencyGraph type.
var steps []Step
if sg.opts.TrustDependencies {
toReplace, res := sg.calculateDependentReplacements(old)
if res != nil {
return nil, res
}
// Deletions must occur in reverse dependency order, and `deps` is returned in dependency
// order, so we iterate in reverse.
for i := len(toReplace) - 1; i >= 0; i-- {
dependentResource := toReplace[i].res
// If we already deleted this resource due to some other DBR, don't do it again.
if sg.deletes[dependentResource.URN] {
continue
}
sg.dependentReplaceKeys[dependentResource.URN] = toReplace[i].keys
logging.V(7).Infof("Planner decided to delete '%v' due to dependence on condemned resource '%v'",
dependentResource.URN, urn)
steps = append(steps, NewDeleteReplacementStep(sg.plan, dependentResource, true))
// Mark the condemned resource as deleted. We won't know until later in the plan whether
// or not we're going to be replacing this resource.
sg.deletes[dependentResource.URN] = true
}
}
return append(steps,
NewDeleteReplacementStep(sg.plan, old, true),
NewReplaceStep(sg.plan, old, new, diff.ReplaceKeys, diff.ChangedKeys, diff.DetailedDiff, false),
NewCreateReplacementStep(
sg.plan, event, old, new, diff.ReplaceKeys, diff.ChangedKeys, diff.DetailedDiff, false),
), nil
}
return []Step{
NewCreateReplacementStep(
sg.plan, event, old, new, diff.ReplaceKeys, diff.ChangedKeys, diff.DetailedDiff, true),
NewReplaceStep(sg.plan, old, new, diff.ReplaceKeys, diff.ChangedKeys, diff.DetailedDiff, true),
// note that the delete step is generated "later" on, after all creates/updates finish.
}, nil
}
// If we fell through, it's an update.
sg.updates[urn] = true
if logging.V(7) {
logging.V(7).Infof("Planner decided to update '%v' (oldprops=%v inputs=%v", urn, oldInputs, new.Inputs)
}
return []Step{
NewUpdateStep(sg.plan, event, old, new, diff.StableKeys, diff.ChangedKeys, diff.DetailedDiff,
goal.IgnoreChanges),
}, nil
}
// If resource was unchanged, but there were initialization errors, generate an empty update
// step to attempt to "continue" awaiting initialization.
if len(old.InitErrors) > 0 {
sg.updates[urn] = true
return []Step{NewUpdateStep(sg.plan, event, old, new, diff.StableKeys, nil, nil, nil)}, nil
}
return nil, nil
}
func (sg *stepGenerator) GenerateDeletes(targetsOpt map[resource.URN]bool) ([]Step, result.Result) {
// To compute the deletion list, we must walk the list of old resources *backwards*. This is because the list is
// stored in dependency order, and earlier elements are possibly leaf nodes for later elements. We must not delete
// dependencies prior to their dependent nodes.
var dels []Step
if prev := sg.plan.prev; prev != nil {
for i := len(prev.Resources) - 1; i >= 0; i-- {
// If this resource is explicitly marked for deletion or wasn't seen at all, delete it.
res := prev.Resources[i]
if res.Delete {
// The below assert is commented-out because it's believed to be wrong.
//
// The original justification for this assert is that the author (swgillespie) believed that
// it was impossible for a single URN to be deleted multiple times in the same program.
// This has empirically been proven to be false - it is possible using today engine to construct
// a series of actions that puts arbitrarily many pending delete resources with the same URN in
// the snapshot.
//
// It is not clear whether or not this is OK. I (swgillespie), the author of this comment, have
// seen no evidence that it is *not* OK. However, concerns were raised about what this means for
// structural resources, and so until that question is answered, I am leaving this comment and
// assert in the code.
//
// Regardless, it is better to admit strange behavior in corner cases than it is to crash the CLI
// whenever we see multiple deletes for the same URN.
// contract.Assert(!sg.deletes[res.URN])
if sg.pendingDeletes[res] {
logging.V(7).Infof(
"Planner ignoring pending-delete resource (%v, %v) that was already deleted", res.URN, res.ID)
continue
}
if sg.deletes[res.URN] {
logging.V(7).Infof(
"Planner is deleting pending-delete urn '%v' that has already been deleted", res.URN)
}
logging.V(7).Infof("Planner decided to delete '%v' due to replacement", res.URN)
sg.deletes[res.URN] = true
dels = append(dels, NewDeleteReplacementStep(sg.plan, res, false))
} else if _, aliased := sg.aliased[res.URN]; !sg.sames[res.URN] && !sg.updates[res.URN] && !sg.replaces[res.URN] &&
!sg.reads[res.URN] && !aliased {
// NOTE: we deliberately do not check sg.deletes here, as it is possible for us to issue multiple
// delete steps for the same URN if the old checkpoint contained pending deletes.
logging.V(7).Infof("Planner decided to delete '%v'", res.URN)
sg.deletes[res.URN] = true
if !res.PendingReplacement {
dels = append(dels, NewDeleteStep(sg.plan, res))
} else {
dels = append(dels, NewRemovePendingReplaceStep(sg.plan, res))
}
}
}
}
// If -target was provided to either `pulumi update` or `pulumi destroy` then only delete
// resources that were specified.
allowedResourcesToDelete, res := sg.determineAllowedResourcesToDeleteFromTargets(targetsOpt)
if res != nil {
return nil, res
}
if allowedResourcesToDelete != nil {
filtered := []Step{}
for _, step := range dels {
if _, has := allowedResourcesToDelete[step.URN()]; has {
filtered = append(filtered, step)
}
}
dels = filtered
}
deletingUnspecifiedTarget := false
for _, step := range dels {
urn := step.URN()
if targetsOpt != nil && !targetsOpt[urn] && !sg.opts.TargetDependents {
d := diag.GetResourceWillBeDestroyedButWasNotSpecifiedInTargetList(urn)
// Targets were specified, but didn't include this resource to create. Report all the
// problematic targets so the user doesn't have to keep adding them one at a time and
// re-running the operation.
//
// Mark that step generation entered an error state so that the entire app run fails.
sg.plan.Diag().Errorf(d, urn)
sg.sawError = true
deletingUnspecifiedTarget = true
}
}
if deletingUnspecifiedTarget && !sg.plan.preview {
// In preview we keep going so that the user will hear about all the problems and can then
// fix up their command once (as opposed to adding a target, rerunning, adding a target,
// rerunning, etc. etc.).
//
// Doing a normal run. We should not proceed here at all. We don't want to delete
// something the user didn't ask for.
return nil, result.Bail()
}
return dels, nil
}
func (sg *stepGenerator) determineAllowedResourcesToDeleteFromTargets(
targetsOpt map[resource.URN]bool) (map[resource.URN]bool, result.Result) {
if targetsOpt == nil {
// no specific targets, so we won't filter down anything
return nil, nil
}
logging.V(7).Infof("Planner was asked to only delete/update '%v'", targetsOpt)
resourcesToDelete := make(map[resource.URN]bool)
// Now actually use all the requested targets to figure out the exact set to delete.
for target := range targetsOpt {
current := sg.plan.olds[target]
if current == nil {
// user specified a target that didn't exist. they will have already gotten a warning
// about this when we called checkTargets. explicitly ignore this target since it won't
// be something we could possibly be trying to delete, nor could have dependents we
// might need to replace either.
continue
}
resourcesToDelete[target] = true
// the item the user is asking to destroy may cause downstream replacements. Clean those up
// as well. Use the standard delete-before-replace computation to determine the minimal
// set of downstream resources that are affected.
deps, res := sg.calculateDependentReplacements(current)
if res != nil {
return nil, res
}
for _, dep := range deps {
logging.V(7).Infof("GenerateDeletes(...): Adding dependent: %v", dep.res.URN)
resourcesToDelete[dep.res.URN] = true
}
}
// Also see if any resources have a resource we're deleting as a parent. If so, we'll block
// the delete. It's a little painful. But can be worked around by explicitly deleting
// children before parents. Note: in almost all cases, people will want to delete children,
// so this restriction should not be too onerous.
for _, res := range sg.plan.prev.Resources {
if res.Parent != "" {
if _, has := resourcesToDelete[res.URN]; has {
// already deleting this sibling
continue
}
if _, has := resourcesToDelete[res.Parent]; has {
sg.plan.Diag().Errorf(diag.GetCannotDeleteParentResourceWithoutAlsoDeletingChildError(res.Parent),
res.Parent, res.URN)
return nil, result.Bail()
}
}
}
if logging.V(7) {
keys := []resource.URN{}
for k := range resourcesToDelete {
keys = append(keys, k)
}
logging.V(7).Infof("Planner will delete all of '%v'", keys)
}
return resourcesToDelete, nil
}
// GeneratePendingDeletes generates delete steps for all resources that are pending deletion. This function should be
// called at the start of a plan in order to find all resources that are pending deletion from the prevous plan.
func (sg *stepGenerator) GeneratePendingDeletes() []Step {
var dels []Step
if prev := sg.plan.prev; prev != nil {
logging.V(7).Infof("stepGenerator.GeneratePendingDeletes(): scanning previous snapshot for pending deletes")
for i := len(prev.Resources) - 1; i >= 0; i-- {
res := prev.Resources[i]
if res.Delete {
logging.V(7).Infof(
"stepGenerator.GeneratePendingDeletes(): resource (%v, %v) is pending deletion", res.URN, res.ID)
sg.pendingDeletes[res] = true
dels = append(dels, NewDeleteStep(sg.plan, res))
}
}
}
return dels
}
// scheduleDeletes takes a list of steps that will delete resources and "schedules" them by producing a list of list of
// steps, where each list can be executed in parallel but a previous list must be executed to completion before advacing
// to the next list.
//
// In lieu of tracking per-step dependencies and orienting the step executor around these dependencies, this function
// provides a conservative approximation of what deletions can safely occur in parallel. The insight here is that the
// resource dependency graph is a partially-ordered set and all partially-ordered sets can be easily decomposed into
// antichains - subsets of the set that are all not comparable to one another. (In this definition, "not comparable"
// means "do not depend on one another").
//
// The algorithm for decomposing a poset into antichains is:
// 1. While there exist elements in the poset,
// 1a. There must exist at least one "maximal" element of the poset. Let E_max be those elements.
// 2a. Remove all elements E_max from the poset. E_max is an antichain.
// 3a. Goto 1.
//
// Translated to our dependency graph:
// 1. While the set of condemned resources is not empty:
// 1a. Remove all resources with no outgoing edges from the graph and add them to the current antichain.
// 2a. Goto 1.
//
// The resulting list of antichains is a list of list of steps that can be safely executed in parallel. Since we must
// process deletes in reverse (so we don't delete resources upon which other resources depend), we reverse the list and
// hand it back to the plan executor for safe execution.
func (sg *stepGenerator) ScheduleDeletes(deleteSteps []Step) []antichain {
var antichains []antichain // the list of parallelizable steps we intend to return.
dg := sg.plan.depGraph // the current plan's dependency graph.
condemned := make(graph.ResourceSet) // the set of condemned resources.
stepMap := make(map[*resource.State]Step) // a map from resource states to the steps that delete them.
// If we don't trust the dependency graph we've been given, we must be conservative and delete everything serially.
if !sg.opts.TrustDependencies {
logging.V(7).Infof("Planner does not trust dependency graph, scheduling deletions serially")
for _, step := range deleteSteps {
antichains = append(antichains, antichain{step})
}
return antichains
}
logging.V(7).Infof("Planner trusts dependency graph, scheduling deletions in parallel")
// For every step we've been given, record it as condemned and save the step that will be used to delete it. We'll
// iteratively place these steps into antichains as we remove elements from the condemned set.
for _, step := range deleteSteps {
condemned[step.Res()] = true
stepMap[step.Res()] = step
}
for len(condemned) > 0 {
var steps antichain
logging.V(7).Infof("Planner beginning schedule of new deletion antichain")
for res := range condemned {
// Does res have any outgoing edges to resources that haven't already been removed from the graph?
condemnedDependencies := dg.DependenciesOf(res).Intersect(condemned)
if len(condemnedDependencies) == 0 {
// If not, it's safe to delete res at this stage.
logging.V(7).Infof("Planner scheduling deletion of '%v'", res.URN)
steps = append(steps, stepMap[res])
}
// If one of this resource's dependencies or this resource's parent hasn't been removed from the graph yet,
// it can't be deleted this round.
}
// For all reosurces that are to be deleted in this round, remove them from the graph.
for _, step := range steps {
delete(condemned, step.Res())
}
antichains = append(antichains, steps)
}
// Up until this point, all logic has been "backwards" - we're scheduling resources for deletion when all of their
// dependencies finish deletion, but that's exactly the opposite of what we need to do. We can only delete a
// resource when all *resources that depend on it* complete deletion. Our solution is still correct, though, it's
// just backwards.
//
// All we have to do here is reverse the list and then our solution is correct.
for i := len(antichains)/2 - 1; i >= 0; i-- {
opp := len(antichains) - 1 - i
antichains[i], antichains[opp] = antichains[opp], antichains[i]
}
return antichains
}
// providerChanged diffs the Provider field of old and new resources, returning true if the rest of the step generator
// should consider there to be a diff between these two resources.
func (sg *stepGenerator) providerChanged(urn resource.URN, old, new *resource.State) (bool, error) {
// If a resource's Provider field has changed, we may need to show a diff and we may not. This is subtle. See
// pulumi/pulumi#2753 for more details.
//
// Recent versions of Pulumi allow for language hosts to pass a plugin version to the engine. The purpose of this is
// to ensure that the plugin that the engine uses for a particular resource is *exactly equal* to the version of the
// SDK that the language host used to produce the resource registration. This is critical for correct versioning
// semantics; it is generally an error for a language SDK to produce a registration that is serviced by a
// differently versioned plugin, since the two version in complete lockstep and there is no guarantee that the two
// will work correctly together when not the same version.
if old.Provider == new.Provider {
return false, nil
}
logging.V(stepExecutorLogLevel).Infof("sg.diffProvider(%s, ...): observed provider diff", urn)
logging.V(stepExecutorLogLevel).Infof("sg.diffProvider(%s, ...): %s => %s", urn, old.Provider, new.Provider)
oldRef, err := providers.ParseReference(old.Provider)
if err != nil {
return false, err
}
newRef, err := providers.ParseReference(new.Provider)
if err != nil {
return false, err
}
// If one or both of these providers are not default providers, we will need to accept the diff and replace
// everything. This might not be strictly necessary, but it is conservatively correct.
if !providers.IsDefaultProvider(oldRef.URN()) || !providers.IsDefaultProvider(newRef.URN()) {
logging.V(stepExecutorLogLevel).Infof(
"sg.diffProvider(%s, ...): reporting provider diff due to change in default provider status", urn)
logging.V(stepExecutorLogLevel).Infof(
"sg.diffProvider(%s, ...): old provider %q is default: %v",
urn, oldRef.URN(), providers.IsDefaultProvider(oldRef.URN()))
logging.V(stepExecutorLogLevel).Infof(
"sg.diffProvider(%s, ...): new provider %q is default: %v",
urn, newRef.URN(), providers.IsDefaultProvider(newRef.URN()))
return true, err
}
// If both of these providers are default providers, use the *new provider* to diff the config and determine if
// this provider requires replacement.
//
// Note that, if we have many resources managed by the same provider that is getting replaced in this manner,
// this will call DiffConfig repeatedly with the same arguments for every resource. If this becomes a
// performance problem, this result can be cached.
newProv, ok := sg.plan.providers.GetProvider(newRef)
if !ok {
return false, errors.Errorf("failed to resolve provider reference: %q", oldRef.String())
}
oldRes, ok := sg.plan.olds[oldRef.URN()]
contract.Assertf(ok, "old state didn't have provider, despite resource using it?")
newRes, ok := sg.providers[newRef.URN()]
contract.Assertf(ok, "new plan didn't have provider, despite resource using it?")
diff, err := newProv.DiffConfig(newRef.URN(), oldRes.Inputs, newRes.Inputs, true, nil)
if err != nil {
return false, err
}
// If there is a replacement diff, we must also replace this resource.
if diff.Replace() {
logging.V(stepExecutorLogLevel).Infof(
"sg.diffProvider(%s, ...): new provider's DiffConfig reported replacement", urn)
return true, nil