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.
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.
Computed primitive values must see the UnknownConfigValue or they are
assumed to be unchanged. Restrict the usage of the protov5 ComputedKeys
to containers.
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.
These are the largest source of the old "diffs didn't match after apply"
errors. It's almost always an upstream dependency that caused the final
error.
The helper/schema handling of lists loses empty string values, but
retains the correct count. Only re-count the values if the count is
missing entirely, and allow our shims to re-populate the zero values.
Terraform core expects a sane state even when the provider returns an
error. Make sure at the prior state is always the default value to
return, and then alway attempt to process any state returned by
provider.Apply.
If there were no matching keys, and there was no diff at all, don't set
a zero count for the container. Normally Providers can't reliably detect
empty vs unset here, but there are some cases that worked.
Fixes a case where ResourceConfig.get inadvertently returns a nil value.
Add an integration test where assigning a map to a list via
interpolation would panic.
This set of changes addresses two bug scenarios:
(1) When an ignored change canceled a resource replacement, any
downstream resources referencing computer attributes on that resource
would get "diffs didn't match" errors. This happened because the
`EvalDiff` implementation was calling `state.MergeDiff(diff)` on the
unfiltered diff. Generally this is what you want, so that downstream
references catch the "incoming" values. When there's a potential for the
diff to change, thought, this results in problems w/ references.
Here we solve this by doing away with the separate `EvalNode` for
`ignore_changes` processing and integrating it into `EvalDiff`. This
allows us to only call `MergeDiff` with the final, filtered diff.
(2) When a resource had an ignored change but was still being replaced
anyways, the diff was being improperly filtered. This would cause
problems during apply when not all attributes were available to perform
the replacement.
We solve that by deferring actual attribute removal until after we've
decided that we do not have to replace the resource.
In #7170 we found two scenarios where the type checking done during the
`context.Validate()` graph walk was circumvented, and the subsequent
assumption of type safety in the provider's `Diff()` implementation
caused panics.
Both scenarios have to do with interpolations that reference Computed
values. The sentinel we use to indicate that a value is Computed does
not carry any type information with it yet.
That means that an incorrect reference to a list or a map in a string
attribute can "sneak through" validation only to crop up...
1. ...during Plan for Data Source References
2. ...during Apply for Resource references
In order to address this, we:
* add high-level tests for each of these two scenarios in `provider/test`
* add context-level tests for the same two scenarios in `terraform`
(these tests proved _really_ tricky to write!)
* place an `EvalValidateResource` just before `EvalDiff` and `EvalApply` to
catch these errors
* add some plumbing to `Plan()` and `Apply()` to return validation
errors, which were previously only generated during `Validate()`
* wrap unit-tests around `EvalValidateResource`
* add an `IgnoreWarnings` option to `EvalValidateResource` to prevent
active warnings from halting execution on the second-pass validation
Eventually, we might be able to attach type information to Computed
values, which would allow for these errors to be caught earlier. For
now, this solution keeps us safe from panics and raises the proper
errors to the user.
Fixes#7170
For a long time now, the diff logic has relied on the behavior of
`mapstructure.WeakDecode` to determine how various primitives are
converted into strings. The `schema.DiffString` function is used for
all primitive field types: TypeBool, TypeInt, TypeFloat, and TypeString.
The `mapstructure` library's string representation of booleans is "0"
and "1", which differs from `strconv.FormatBool`'s "false" and "true"
(which is used in writing out boolean fields to the state).
Because of this difference, diffs have long had the potential for
cosmetically odd but semantically neutral output like:
"true" => "1"
"false" => "0"
So long as `mapstructure.Decode` or `strconv.ParseBool` are used to
interpret these strings, there's no functional problem.
We had our first clear functional problem with #6005 and friends, where
users noticed diffs like the above showing up unexpectedly and causing
troubles when `ignore_changes` was in play.
This particular bug occurs down in Terraform core's EvalIgnoreChanges.
There, the diff is modified to account for ignored attributes, and
special logic attempts to handle properly the situation where the
ignored attribute was going to trigger a resource replacement. That
logic relies on the string representations of the Old and New fields in
the diff to be the same so that it filters properly.
So therefore, we now get a bug when a diff includes `Old: "0", New:
"false"` since the strings do not match, and `ignore_changes` is not
properly handled.
Here, we introduce `TypeBool`-specific normalizing into `finalizeDiff`.
I spiked out a full `diffBool` function, but figuring out which pieces
of `diffString` to duplicate there got hairy. This seemed like a simpler
and more direct solution.
Fixes#6005 (and potentially others!)
The ignore_changes diff filter was stripping out attributes on Create
but the diff was still making it down to the provider, so Create would
end up missing attributes, causing a full failure if any required
attributes were being ignored.
In addition, any changes that required a replacement of the resource
were causing problems with `ignore_chages`, which didn't properly filter
out the replacement when the triggering attributes were filtered out.
Refs #5627
Here we also introduce a `test` provider meant as an aid to exposing
via automated tests issues involving interactions between
`helper/schema` and Terraform core.
This has been helpful so far in diagnosing `ignore_changes` problems,
and I imagine it will be helpful in other contexts as well.
We'll have to be careful to prevent the `test` provider from becoming a
dumping ground for poorly specified tests that have a clear home
elsewhere. But for bug exposure I think it's useful to have.
James Bardin