terraform/internal/plans/objchange/plan_valid.go

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package objchange
import (
"fmt"
"github.com/zclconf/go-cty/cty"
"github.com/hashicorp/terraform/internal/configs/configschema"
)
// AssertPlanValid checks checks whether a planned new state returned by a
// provider's PlanResourceChange method is suitable to achieve a change
// from priorState to config. It returns a slice with nonzero length if
// any problems are detected. Because problems here indicate bugs in the
// provider that generated the plannedState, they are written with provider
// developers as an audience, rather than end-users.
//
// All of the given values must have the same type and must conform to the
// implied type of the given schema, or this function may panic or produce
// garbage results.
//
// During planning, a provider may only make changes to attributes that are
// null (unset) in the configuration and are marked as "computed" in the
// resource type schema, in order to insert any default values the provider
// may know about. If the default value cannot be determined until apply time,
// the provider can return an unknown value. Providers are forbidden from
// planning a change that disagrees with any non-null argument in the
// configuration.
//
// As a special exception, providers _are_ allowed to provide attribute values
// conflicting with configuration if and only if the planned value exactly
// matches the corresponding attribute value in the prior state. The provider
// can use this to signal that the new value is functionally equivalent to
// the old and thus no change is required.
func AssertPlanValid(schema *configschema.Block, priorState, config, plannedState cty.Value) []error {
return assertPlanValid(schema, priorState, config, plannedState, nil)
}
func assertPlanValid(schema *configschema.Block, priorState, config, plannedState cty.Value, path cty.Path) []error {
var errs []error
if plannedState.IsNull() && !config.IsNull() {
errs = append(errs, path.NewErrorf("planned for absense but config wants existence"))
return errs
}
if config.IsNull() && !plannedState.IsNull() {
errs = append(errs, path.NewErrorf("planned for existence but config wants absense"))
return errs
}
if plannedState.IsNull() {
// No further checks possible if the planned value is null
return errs
}
impTy := schema.ImpliedType()
// verify attributes
moreErrs := assertPlannedAttrsValid(schema.Attributes, priorState, config, plannedState, path)
errs = append(errs, moreErrs...)
for name, blockS := range schema.BlockTypes {
path := append(path, cty.GetAttrStep{Name: name})
plannedV := plannedState.GetAttr(name)
configV := config.GetAttr(name)
priorV := cty.NullVal(impTy.AttributeType(name))
if !priorState.IsNull() {
priorV = priorState.GetAttr(name)
}
if plannedV.RawEquals(configV) {
// Easy path: nothing has changed at all
continue
}
if !plannedV.IsKnown() {
errs = append(errs, path.NewErrorf("attribute representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
switch blockS.Nesting {
configs/configschema: Introduce the NestingGroup mode for blocks In study of existing providers we've found a pattern we werent previously accounting for of using a nested block type to represent a group of arguments that relate to a particular feature that is always enabled but where it improves configuration readability to group all of its settings together in a nested block. The existing NestingSingle was not a good fit for this because it is designed under the assumption that the presence or absence of the block has some significance in enabling or disabling the relevant feature, and so for these always-active cases we'd generate a misleading plan where the settings for the feature appear totally absent, rather than showing the default values that will be selected. NestingGroup is, therefore, a slight variation of NestingSingle where presence vs. absence of the block is not distinguishable (it's never null) and instead its contents are treated as unset when the block is absent. This then in turn causes any default values associated with the nested arguments to be honored and displayed in the plan whenever the block is not explicitly configured. The current SDK cannot activate this mode, but that's okay because its "legacy type system" opt-out flag allows it to force a block to be processed in this way anyway. We're adding this now so that we can introduce the feature in a future SDK without causing a breaking change to the protocol, since the set of possible block nesting modes is not extensible.
2019-04-09 00:32:53 +02:00
case configschema.NestingSingle, configschema.NestingGroup:
moreErrs := assertPlanValid(&blockS.Block, priorV, configV, plannedV, path)
errs = append(errs, moreErrs...)
case configschema.NestingList:
// A NestingList might either be a list or a tuple, depending on
// whether there are dynamically-typed attributes inside. However,
// both support a similar-enough API that we can treat them the
// same for our purposes here.
if plannedV.IsNull() {
errs = append(errs, path.NewErrorf("attribute representing a list of nested blocks must be empty to indicate no blocks, not null"))
continue
}
plannedL := plannedV.LengthInt()
configL := configV.LengthInt()
if plannedL != configL {
errs = append(errs, path.NewErrorf("block count in plan (%d) disagrees with count in config (%d)", plannedL, configL))
continue
}
for it := plannedV.ElementIterator(); it.Next(); {
idx, plannedEV := it.Element()
path := append(path, cty.IndexStep{Key: idx})
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
if !configV.HasIndex(idx).True() {
continue // should never happen since we checked the lengths above
}
configEV := configV.Index(idx)
priorEV := cty.NullVal(blockS.ImpliedType())
if !priorV.IsNull() && priorV.HasIndex(idx).True() {
priorEV = priorV.Index(idx)
}
moreErrs := assertPlanValid(&blockS.Block, priorEV, configEV, plannedEV, path)
errs = append(errs, moreErrs...)
}
case configschema.NestingMap:
if plannedV.IsNull() {
errs = append(errs, path.NewErrorf("attribute representing a map of nested blocks must be empty to indicate no blocks, not null"))
continue
}
// A NestingMap might either be a map or an object, depending on
// whether there are dynamically-typed attributes inside, but
// that's decided statically and so all values will have the same
// kind.
if plannedV.Type().IsObjectType() {
plannedAtys := plannedV.Type().AttributeTypes()
configAtys := configV.Type().AttributeTypes()
for k := range plannedAtys {
if _, ok := configAtys[k]; !ok {
errs = append(errs, path.NewErrorf("block key %q from plan is not present in config", k))
continue
}
path := append(path, cty.GetAttrStep{Name: k})
plannedEV := plannedV.GetAttr(k)
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
configEV := configV.GetAttr(k)
priorEV := cty.NullVal(blockS.ImpliedType())
if !priorV.IsNull() && priorV.Type().HasAttribute(k) {
priorEV = priorV.GetAttr(k)
}
moreErrs := assertPlanValid(&blockS.Block, priorEV, configEV, plannedEV, path)
errs = append(errs, moreErrs...)
}
for k := range configAtys {
if _, ok := plannedAtys[k]; !ok {
errs = append(errs, path.NewErrorf("block key %q from config is not present in plan", k))
continue
}
}
} else {
plannedL := plannedV.LengthInt()
configL := configV.LengthInt()
if plannedL != configL {
errs = append(errs, path.NewErrorf("block count in plan (%d) disagrees with count in config (%d)", plannedL, configL))
continue
}
for it := plannedV.ElementIterator(); it.Next(); {
idx, plannedEV := it.Element()
path := append(path, cty.IndexStep{Key: idx})
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
k := idx.AsString()
if !configV.HasIndex(idx).True() {
errs = append(errs, path.NewErrorf("block key %q from plan is not present in config", k))
continue
}
configEV := configV.Index(idx)
priorEV := cty.NullVal(blockS.ImpliedType())
if !priorV.IsNull() && priorV.HasIndex(idx).True() {
priorEV = priorV.Index(idx)
}
moreErrs := assertPlanValid(&blockS.Block, priorEV, configEV, plannedEV, path)
errs = append(errs, moreErrs...)
}
for it := configV.ElementIterator(); it.Next(); {
idx, _ := it.Element()
if !plannedV.HasIndex(idx).True() {
errs = append(errs, path.NewErrorf("block key %q from config is not present in plan", idx.AsString()))
continue
}
}
}
case configschema.NestingSet:
if plannedV.IsNull() {
errs = append(errs, path.NewErrorf("attribute representing a set of nested blocks must be empty to indicate no blocks, not null"))
continue
}
// Because set elements have no identifier with which to correlate
// them, we can't robustly validate the plan for a nested block
// backed by a set, and so unfortunately we need to just trust the
// provider to do the right thing. :(
//
// (In principle we could correlate elements by matching the
// subset of attributes explicitly set in config, except for the
// special diff suppression rule which allows for there to be a
// planned value that is constructed by mixing part of a prior
// value with part of a config value, creating an entirely new
// element that is not present in either prior nor config.)
for it := plannedV.ElementIterator(); it.Next(); {
idx, plannedEV := it.Element()
path := append(path, cty.IndexStep{Key: idx})
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
}
default:
panic(fmt.Sprintf("unsupported nesting mode %s", blockS.Nesting))
}
}
return errs
}
func assertPlannedAttrsValid(schema map[string]*configschema.Attribute, priorState, config, plannedState cty.Value, path cty.Path) []error {
var errs []error
for name, attrS := range schema {
moreErrs := assertPlannedAttrValid(name, attrS, priorState, config, plannedState, path)
errs = append(errs, moreErrs...)
}
return errs
}
func assertPlannedAttrValid(name string, attrS *configschema.Attribute, priorState, config, plannedState cty.Value, path cty.Path) []error {
plannedV := plannedState.GetAttr(name)
configV := config.GetAttr(name)
priorV := cty.NullVal(attrS.Type)
if !priorState.IsNull() {
priorV = priorState.GetAttr(name)
}
path = append(path, cty.GetAttrStep{Name: name})
return assertPlannedValueValid(attrS, priorV, configV, plannedV, path)
}
func assertPlannedValueValid(attrS *configschema.Attribute, priorV, configV, plannedV cty.Value, path cty.Path) []error {
var errs []error
if plannedV.RawEquals(configV) {
// This is the easy path: provider didn't change anything at all.
return errs
}
if plannedV.RawEquals(priorV) && !priorV.IsNull() && !configV.IsNull() {
// Also pretty easy: there is a prior value and the provider has
// returned it unchanged. This indicates that configV and plannedV
// are functionally equivalent and so the provider wishes to disregard
// the configuration value in favor of the prior.
return errs
}
// the provider is allowed to insert values when the config is
// null, but only if the attribute is computed.
if configV.IsNull() {
if attrS.Computed {
return errs
}
// if the attribute is not computed, then any planned value is incorrect
if !plannedV.IsNull() {
if attrS.Sensitive {
errs = append(errs, path.NewErrorf("sensitive planned value for a non-computed attribute"))
} else {
errs = append(errs, path.NewErrorf("planned value %#v for a non-computed attribute", plannedV))
}
return errs
}
}
// If this attribute has a NestedType, validate the nested object
if attrS.NestedType != nil {
return assertPlannedObjectValid(attrS.NestedType, priorV, configV, plannedV, path)
}
// If none of the above conditions match, the provider has made an invalid
// change to this attribute.
if priorV.IsNull() {
if attrS.Sensitive {
errs = append(errs, path.NewErrorf("sensitive planned value does not match config value"))
} else {
errs = append(errs, path.NewErrorf("planned value %#v does not match config value %#v", plannedV, configV))
}
return errs
}
if attrS.Sensitive {
errs = append(errs, path.NewErrorf("sensitive planned value does not match config value nor prior value"))
} else {
errs = append(errs, path.NewErrorf("planned value %#v does not match config value %#v nor prior value %#v", plannedV, configV, priorV))
}
return errs
}
func assertPlannedObjectValid(schema *configschema.Object, prior, config, planned cty.Value, path cty.Path) []error {
var errs []error
if planned.IsNull() && !config.IsNull() {
errs = append(errs, path.NewErrorf("planned for absense but config wants existence"))
return errs
}
if config.IsNull() && !planned.IsNull() {
errs = append(errs, path.NewErrorf("planned for existence but config wants absense"))
return errs
}
if planned.IsNull() {
// No further checks possible if the planned value is null
return errs
}
switch schema.Nesting {
case configschema.NestingSingle, configschema.NestingGroup:
moreErrs := assertPlannedAttrsValid(schema.Attributes, prior, config, planned, path)
errs = append(errs, moreErrs...)
case configschema.NestingList:
// A NestingList might either be a list or a tuple, depending on
// whether there are dynamically-typed attributes inside. However,
// both support a similar-enough API that we can treat them the
// same for our purposes here.
plannedL := planned.LengthInt()
configL := config.LengthInt()
if plannedL != configL {
errs = append(errs, path.NewErrorf("count in plan (%d) disagrees with count in config (%d)", plannedL, configL))
return errs
}
for it := planned.ElementIterator(); it.Next(); {
idx, plannedEV := it.Element()
path := append(path, cty.IndexStep{Key: idx})
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
if !config.HasIndex(idx).True() {
continue // should never happen since we checked the lengths above
}
configEV := config.Index(idx)
priorEV := cty.NullVal(schema.ImpliedType())
if !prior.IsNull() && prior.HasIndex(idx).True() {
priorEV = prior.Index(idx)
}
moreErrs := assertPlannedAttrsValid(schema.Attributes, priorEV, configEV, plannedEV, path)
errs = append(errs, moreErrs...)
}
case configschema.NestingMap:
// A NestingMap might either be a map or an object, depending on
// whether there are dynamically-typed attributes inside, but
// that's decided statically and so all values will have the same
// kind.
if planned.Type().IsObjectType() {
plannedAtys := planned.Type().AttributeTypes()
configAtys := config.Type().AttributeTypes()
for k := range plannedAtys {
if _, ok := configAtys[k]; !ok {
errs = append(errs, path.NewErrorf("block key %q from plan is not present in config", k))
continue
}
path := append(path, cty.GetAttrStep{Name: k})
plannedEV := planned.GetAttr(k)
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
configEV := config.GetAttr(k)
priorEV := cty.NullVal(schema.ImpliedType())
if !prior.IsNull() && prior.Type().HasAttribute(k) {
priorEV = prior.GetAttr(k)
}
moreErrs := assertPlannedAttrsValid(schema.Attributes, priorEV, configEV, plannedEV, path)
errs = append(errs, moreErrs...)
}
for k := range configAtys {
if _, ok := plannedAtys[k]; !ok {
errs = append(errs, path.NewErrorf("block key %q from config is not present in plan", k))
continue
}
}
} else {
plannedL := planned.LengthInt()
configL := config.LengthInt()
if plannedL != configL {
errs = append(errs, path.NewErrorf("block count in plan (%d) disagrees with count in config (%d)", plannedL, configL))
return errs
}
for it := planned.ElementIterator(); it.Next(); {
idx, plannedEV := it.Element()
path := append(path, cty.IndexStep{Key: idx})
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
k := idx.AsString()
if !config.HasIndex(idx).True() {
errs = append(errs, path.NewErrorf("block key %q from plan is not present in config", k))
continue
}
configEV := config.Index(idx)
priorEV := cty.NullVal(schema.ImpliedType())
if !prior.IsNull() && prior.HasIndex(idx).True() {
priorEV = prior.Index(idx)
}
moreErrs := assertPlannedObjectValid(schema, priorEV, configEV, plannedEV, path)
errs = append(errs, moreErrs...)
}
for it := config.ElementIterator(); it.Next(); {
idx, _ := it.Element()
if !planned.HasIndex(idx).True() {
errs = append(errs, path.NewErrorf("block key %q from config is not present in plan", idx.AsString()))
continue
}
}
}
case configschema.NestingSet:
// Because set elements have no identifier with which to correlate
// them, we can't robustly validate the plan for a nested block
// backed by a set, and so unfortunately we need to just trust the
// provider to do the right thing. :(
//
// (In principle we could correlate elements by matching the
// subset of attributes explicitly set in config, except for the
// special diff suppression rule which allows for there to be a
// planned value that is constructed by mixing part of a prior
// value with part of a config value, creating an entirely new
// element that is not present in either prior nor config.)
for it := planned.ElementIterator(); it.Next(); {
idx, plannedEV := it.Element()
path := append(path, cty.IndexStep{Key: idx})
if !plannedEV.IsKnown() {
errs = append(errs, path.NewErrorf("element representing nested block must not be unknown itself; set nested attribute values to unknown instead"))
continue
}
}
}
return errs
}