When upgrading from a flatmap state, unset blocks would not exist in the
state, while they will represented as empty in the new cty.Value. This
will cause an unexpected diff in the first plan after upgrade. This
situation may normally be applied with no impact, but some providers may
have unexpected behavior, and if the attributes force replacement it may
require manual alteration of the state to complete the upgrade.
When a Diff contains a NewRemoved attribute (which would have been null
in the planned state), the final value is often the "zero" value string
for the type, which the provider itself still applies to the state.
Rather than risking a change of behavior in helper/schema by fixing the
inconsistency, we'll remove the NewRemoved attributes after apply to
prevent further issues resulting from the change in planned value.
Re-seeding the PRNG every time only serves to make the output an
obfuscated timestamp. On windows with a low clock resolution, this
manifests itself by outputting the same value on calls within the
minimum time delta of the clock.
Reference: https://github.com/terraform-providers/terraform-provider-aws/issues/8828
Prior to Terraform 0.12, providers were not required to implement the `MigrateState` function when increasing the `SchemaVersion` above `0`. Effectively there is no flatmap state difference between version 0 and defined `SchemaVersion` or lowest `StateUpgrader` `Version` (whichever is lowest) when `MigrateState` is undefined, so here we remove the error and increase the schema version automatically.
Send Private data blob through ReadResource as well. This will allow for
extra flexibility for future providers that may want to pass data out of
band through to their resource Read functions.
Having removed the methods, it is straightforward to mechanically update
this file to get rid of all references to the "legacy schema". There is
now only one config schema type to deal with in the sdk.
This experiment is no longer needed for handling computed blocks, since
the legacy SDK can't reasonably handle Dynamic types, we need to remove
this before the final release.
Remove LegacySchema functions as well, since handling SkipCoreTypeCheck
was the only thing left they were handling.
When handling the json state in UpgradeResourceState, the schema
must be what core uses, because that is the schema used for
encoding/decoding the json state.
When converting from flatmap to json state, the legacy schema will be
used to decode the flatmap to a cty value, but the resulting json will
be encoded using the CoreConfigSchema to match what core expects.
When normalizing the state during read, if the resource was previously
imported, most nil-able values will be nil, and we need to prefer the
values returned by the latest Read operation. This didn't come up
before, because Read is usually working with a state create by plan and
Apply which has already shaped the state with the expected empty values.
Having the src value preferred only during Apply better follows the
intent of this function, which should allow Read to return whatever
values it deems necessary. Since Read and Plan use the same
normalization logic, the implied Read before plan should take care of any
perpetual diffs.
The new type system only has a Number type, but helper schema
differentiates between Int and Float values. Verify that a new config
value is an integer during Validate, because the existing WeakDecode
validation will decode a float value into an integer while the config
FieldReader will attempt to parse the float exactly.
Since we're limiting this to protoV5, we can be certain that any valid
config value will be converted to an `int` type by the shims. The only
case where an integral float value will appear is if the integer is out
of range for the systems `int` type, but we also need to prevent that
anyway since it would fail to read in the same manner.
Terraform core would previously ignore unexpected attributes found in
the state, but since we now need to encode/decode the state according
the schema, the attributes must match the schema.
On any state upgrade, remove attributes no longer present in the schema
from the state. The only change this requires from providers is that
going forward removal of attribute is considered a schema change, and
requires an increment of the SchemaVersion in order to trigger the
removal of the attributes from state.
Computed primitive values must see the UnknownConfigValue or they are
assumed to be unchanged. Restrict the usage of the protov5 ComputedKeys
to containers.
First check the ComputedValues field in the config when reading config
field, so that we can detect if there is an unknown value in a
container. Since maps, lists and sets are verified to exist by looking
for a "length" first, an unknown config value in the config is ignored.
The grpc server does not shutdown when the listener is closed. Since
tests aren't run through go-plugin, which has a separate RPC Shutdown
channel to stop the server, we need to track and stop the server
directly.
Make sure values removed from a map during apply are not copied into the
new map. The broken test is no longer valid in this case, and the
updated diff.Apply should prevent the case it used to cover.
removeConfigUnknowns need to remove the value completely from the config
map. Removing this value allows GetOk and GetOkExists to indicate if the
value was set in the config in the case of an Optional+Computed
attribute.
We previously attempted to make the special diff apply behavior for nested
sets of objects work with attribute mode by totally discarding attribute
mode for all shims.
In practice, that is too broad a solution: there are lots of other shimming
behaviors that we _don't_ want when attribute mode is enabled. In
particular, we need to make sure that the difference between null and
empty can be seen in configuration.
As a compromise then, we will give all of the shims access to the real
ConfigMode and then do a more specialized fixup within the diff-apply
logic: we'll construct a synthetic nested block schema and then use that
to run our existing logic to deal with nested sets of objects, while
using the previous behavior in all other cases.
In effect, this means that the special new behavior only applies when the
provider uses the opt-in ConfigMode setting on a particular attribute,
and thus this change has much less risk of causing broad, unintended
regressions elsewhere.
Due to the lossiness of our legacy models for diff and state, shimming a
diff and then creating a state from it produces a different result than
shimming a state directly. That means that ImportStateVerify no longer
works as expected if there are any Computed attributes in the schema where
d.Set isn't called during Read.
Fixing that for every case would require some risky changes to the shim
behavior, so we're instead going to ask provider developers to address it
by adding `d.Set` calls where needed, since that is the contract for
"Computed" anyway -- a default value should be produced during Create, and
thus by extension during Import.
However, since a common situation where this occurs is attributes marked
as "Removed", since all of the code that deals with them has generally
been deleted, we'll avoid problems in that case here by treating Removed
attributes as ignored for the purposes of ImportStateVerify.
This required exporting some functionality that was formerly unexported
in helper/schema, but it's a relatively harmless schema introspection
function so shouldn't be a big deal to export it.
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.
The synthetic config value used to create the Apply diff should contain
no unknown config values. Any remaining UnknownConfigValues were due to
that being used as a placeholder for values yet to be computed, and
these should be marked NewComputed in the diff.
Stripping these was a patch for some provider behavior which was fixed
in other ways, and is no longer needed.
Removing this allows us to implement correct CusomizeDiffFuncs in
providers so that they can mark fields with empty values as computed
during a plan.
A list-like attribute containing null values will present a list to
helper/schema with nils, which can cause panics. Since null values were
not possible in configuration before HCL2 and not supported by the
legacy SDK, return an error to the user.
It turns out that collections containing only unknowns could be lost,
meaning there wasn't a direct correlation between the unknown and null
value which would have otherwise been restored.
The legacy diff process inserts unknown values into an optional+computed
map. Fix these up in post-plan normalization process, by looking for
known strings that were changed to unknown.
Because schema.ResourceDiff can't differentiate between unknown
values and new computed values, unknowns can be lost during an update.
If a planned value converted an unknown to a null, restore the unknown
so that it can be correctly replaced in the final plan.
James Bardin