Previously we were using the experimental HCL 2 repository, but now we'll
shift over to the v2 import path within the main HCL repository as part of
actually releasing HCL 2.0 as stable.
This is a mechanical search/replace to the new import paths. It also
switches to the v2.0.0 release of HCL, which includes some new code that
Terraform didn't previously have but should not change any behavior that
matters for Terraform's purposes.
For the moment the experimental HCL2 repository is still an indirect
dependency via terraform-config-inspect, so it remains in our go.sum and
vendor directories for the moment. Because terraform-config-inspect uses
a much smaller subset of the HCL2 functionality, this does still manage
to prune the vendor directory a little. A subsequent release of
terraform-config-inspect should allow us to completely remove that old
repository in a future commit.
Remove reflect.DeepEqual from path comparisons to get reliable results.
The equality issues were only noticed going the grpc interface, so add a
corresponding test to the test provider.
Makre sure private data is maintained all the way to destroy. This
slipped through, since private data isn't used much for current
providers, except for timeouts.
The config is statically validated early on for structural issues, but
the provider can't validate any inputs that were unknown at the time.
Run ValidateResourceTypeConfig during Plan, so that the provider can
validate the final config values, including those interpolated from
other resources.
We are now allowing the legacy SDK to opt out of the safety checks we try
to do after plan and apply, and so in such cases the before/after values
in planned changes may be inconsistent with our usual rules.
To avoid adding lots of extra complexity to the diff renderer to deal with
these situations, instead we'll normalize the handling of nested blocks
prior to using these values.
In the long run it'd be better to do this normalization at the source,
immediately after we receive an object from a provider using the opt-out,
but we're doing this at the outermost layer for now to avoid risking
unintended impacts on other Terraform Core components when we're just
about to enter the beta phase of the v0.12.0 release cycle.
RequiresReplace paths with IndexSteps that have been added or removed
may fail to apply against one of the two state values. Only error out if
the path cannot be applied to both values.
Due to the inprecision of our shimming from the legacy SDK type system to
the new Terraform Core type system, the legacy SDK produces a number of
inconsistencies that produce only minor quirky behavior or broken
edge-cases. To retain compatibility with those existing weird behaviors,
the legacy SDK opts out of our safety checks.
The intent here is to allow existing providers to continue to do their
previous unsafe behaviors for now, accepting that this will allow certain
quirky bugs from previous releases to persist, and then gradually migrate
away from the legacy SDK and remove this opt-out on a per-resource basis
over time.
As with the apply-time safety check opt-out, this is reserved only for
the legacy SDK and must not be used in any new SDK implementations. We
still include any inconsistencies as warnings in the logs as an aid to
anyone debugging weird behavior, so that they can see situations where
blame may be misplaced in the user-visible error messages.
We've been gradually adding safety checks of this sort throughout the
lifecycle to help ensure that buggy providers can't introduce
hard-to-diagnose downstream failures and misbehavior. This completes the
set by verifying during plan time that the provider has produced a plan
that actually achieves the goals defined in the configuration.
In particular, this catches the situation where a provider may incorrectly
override a value explicitly set in configuration, which avoids creating
confusion by betraying the reasonable user expectation that referencing an
explicitly-defined attribute will produce exactly the value shown in
configuration.
We were previously using cty.Path.Apply, which serves a similar purpose
but implements the more restrictive traversal behaviors down at the cty
layer. hcl.ApplyPath uses the same rules as HCL expressions and so ensures
consistent behavior with normal user expressions.
cty.Path.Apply also previously had a crashing bug (discussed in #20084)
that was causing a panic here. That has now been fixed in cty, but since
we're no longer using it here that's a moot point. The HCL traversing
implementation has been fuzz-tested and unit tested a lot more thoroughly
so should not run into the same crashers we saw with cty before.
Previously we were fetching these from the provider but then immediately
discarding the version numbers because the schema API had nowhere to put
them.
To avoid a late-breaking change to the internal structure of
terraform.ProviderSchema (which is constructed directly all over the
tests) we're retaining the resource type schemas in a new map alongside
the existing one with the same keys, rather than just switching to
using the providers.Schema struct directly there.
The methods that return resource type schemas now return two arguments,
intentionally creating a little API friction here so each new caller can
be reminded to think about whether they need to do something with the
schema version, though it can be ignored by many callers.
Since this was a breaking change to the Schemas API anyway, this also
fixes another API wart where there was a separate method for fetching
managed vs. data resource types and thus every caller ended up having a
switch statement on "mode". Now we just accept mode as an argument and
do the switch statement within the single SchemaForResourceType method.
If we don't set it, we end up creating an invalid plan where the destroy
changes don't have a provider address set, which then later fails
decoding when round-tripped through a planfile.
This also includes some extra safety checks in EvalDiff and
EvalDiffDestroy so that we can catch this bug sooner in future.
This change is verified by
TestContext2Apply_plannedDestroyInterpolatedCount, which is now passing.
It doesn't make sense to ignore_changes when the prior value is null,
since we have to create something before we can ignore changes to it.
This change is verified by TestContext2Apply_ignoreChangesWildcard.
This can happen if unknown values in the plan actually end up being
identical to the prior values once resolved. In that case, we'll just make
no change at all.
This is verified by TestContext2Apply_ignoreChangesWithDep.
Previously we used a single plan action "Replace" to represent both the
destroy-before-create and the create-before-destroy variants of replacing.
However, this forces the apply graph builder to jump through a lot of
hoops to figure out which nodes need it forced on and rebuild parts of
the graph to represent that.
If we instead decide between these two cases at plan time, the actual
determination of it is more straightforward because each resource is
represented by only one node in the plan graph, and then we can ensure
we put the right nodes in the graph during DiffTransformer and thus avoid
the logic for dealing with deposed instances being spread across various
different transformers and node types.
As a nice side-effect, this also allows us to show the difference between
destroy-then-create and create-then-destroy in the rendered diff in the
CLI, although this change doesn't fully implement that yet.
When we re-run EvalDiff during apply, we may have already completed the
destroy leg of a replace operation, leaving us in a different situation
than we were when we made the original planned change.
Therefore as a special case we will allow a create to turn back into a
replace if there was an earlier diff that requested that.
If the prior object is tainted, we behave as if it doesn't exist at all
for most of our logic here but then at the end turn it into a synthetic
replace operation going from the old object to the new object, similarly
to how we'd behave if given an argument change that "requires
replacement".
It's not possible for a normal RPC-based provider to get into this
situation because a nil value can't go over the wire, but it's easy to
cause this by not correctly configuring a provider mock during tests.
By panicking early here we produce a more helpful error message and stack
trace than we'd otherwise produce if we let this nil value escape out
into the rest of Terraform.
Since we do our deletes using a separate graph node from all of the other
actions, and a "Replace" change implies both a delete _and_ a create, we
need to pretend at apply time that a single replace change was actually
two separate changes.
This will also early-exit eval if a destroy node finds a non-Delete change
or if an apply node finds a Delete change. These should not happen in
practice because we leave these nodes out of the graph when they are not
needed for the given action, but we do this here for robustness so as not
to have an invisible dependency between the graph builder and the eval
phase.
Prior to our refactoring here, we were relying on a lucky coincidence for
correct behavior of the plan walk following a refresh in the same run:
- The refresh phase created placeholder objects in the state to represent
any resource instance pending creation, to allow the interpolator to
read attributes from them when evaluating "provider" and "data" blocks.
In effect, the refresh walk is creating a partial plan that only covers
creation actions, but was immediately discarding the actual diff entries
and storing only the planned new state.
- It happened that objects pending creation showed up in state with an
empty ID value, since that only gets assigned by the provider during
apply.
- The Refresh function concluded by calling terraform.State.Prune, which
deletes from the state any objects that have an empty ID value, which
therefore prevented these temporary objects from surviving into the
plan phase.
After refactoring, we no longer have this special ID field on instance
object state, and we instead rely on the Status field for tracking such
things. We also no longer have an explicit "prune" step on state, since
the state mutation methods themselves keep the structure pruned.
To address this, here we introduce a new instance object status "planned",
which is equivalent to having an empty ID value in the old world. We also
introduce a new method on states.SyncState that deletes from the state
any planned objects, which therefore replaces that portion of the old
State.prune operation just for this refresh use-case.
Finally, we are now expecting the expression evaluator to pull pending
objects from the planned changeset rather than from the state directly,
and so for correct results these placeholder resource creation changes
must also be reported in a throwaway changeset during the refresh walk.
The addition of states.ObjectPlanned also permits a previously-missing
safety check in the expression evaluator to prevent us from relying on the
incomplete value stored in state for a pending object, in the event that
some bug prevents the real pending object from being written into the
planned changeset.
We were previously tracking this as a []cty.Path, but having it turned
into a pathset on creation makes downstream use of it more convenient and
ensures that it'll obey expected invariants like not containing the same
path twice.
This is no longer a call into the provider, since all of the data diff
logic is standard for all data sources anyway. Instead, we just compute
the planned new value and construct a planned change from that as-is.
Previously the provider could, in principle, customize the read diff. In
practice there is no real reason to do that and the existing SDK didn't
pass that possibility through to provider code, so we can safely change
this without impacting provider compatibility.
This also includes passing in the provider schema to a few more EvalNodes
that were expecting it but not getting it, in order to be able to
successfully test the implementation of EvalReadDiff here.
Chaange ResourceProvider to providers.Interface starting from the
context, and fix all type errors.
This only replaced some of method calls directly applicable to the
providers themselves. The resource methods will follow.
Due to how often the state and plan types are referenced throughout
Terraform, there isn't a great way to switch them out gradually. As a
consequence, this huge commit gets us from the old world to a _compilable_
new world, but still has a large number of known test failures due to
key functionality being stubbed out.
The stubs here are for anything that interacts with providers, since we
now need to do the follow-up work to similarly replace the old
terraform.ResourceProvider interface with its replacement in the new
"providers" package. That work, along with work to fix the remaining
failing tests, will follow in subsequent commits.
The aim here was to replace all references to terraform.State and its
downstream types with states.State, terraform.Plan with plans.Plan,
state.State with statemgr.State, and switch to the new implementations of
the state and plan file formats. However, due to the number of times those
types are used, this also ended up affecting numerous other parts of core
such as terraform.Hook, the backend.Backend interface, and most of the CLI
commands.
Just as with 5861dbf3fc49b19587a31816eb06f511ab861bb4 before, I apologize
in advance to the person who inevitably just found this huge commit while
spelunking through the commit history.
Previously we had the evaluate methods accept directly an
addrs.InstanceKey and had our evaluator infer a suitable value for
count.index for it, but that prevents us from setting the index to be
unknown in the validation scenario where we may not be able to predict
the number of instances yet but we still want to be able to check that
the configuration block is type-safe for all possible count values.
To achieve this, we separate the concern of deciding on a value for
count.index from the concern of evaluating it, which then allows for
other implementations of this in future. For the purpose of this commit
there is no change in behavior, with the count.index value being populated
whenever the instance key is a number.
This commit does a little more groundwork for the future implementation
of the for_each feature (which'll support each.key and each.value) but
still doesn't yet implement it, leaving it just stubbed out for the
moment.
The earlier change 5f07201a made it so that the state is always rewritten
by EvalDiffDestroy, but that was too disruptive to other users of
EvalDiffDestroy.
Now we follow the lead of EvalDiff and have a separate pointer for the
_output_ state, which allows the caller to opt in to having its state
pointer updated to reflect the new (nil) state.
NodePlannableResourceInstanceOrphan is the only caller that currently opts
in to this, since that was the focus of 5f07201a. We may need to make a
similar change to other plannable resource destroy nodes, but we'll wait
to see if that needs to be done in a subsequent commit.
While we're planning we must always update the state with the proposed new
data resulting from the plan. In this case, we must record that the
orphan instance doesn't exist at all in the proposed new state by storing
its state as nil.
This in turn allows references to the containing resource to evaluate
properly, using the new updated resource count. This fixes
TestContext2Apply_multiVarCountDec.
This also includes a number of changes to the test output of
TestContext2Apply_multiVarCountDec that make it easier to debug failures.
On the initial pass here I reached a faulty conclusion about what from
the new world should shim into a NewInstanceInfo, based on a poor read
of existing code.
It actually _should've_ been based on an absolute instance after all,
as evidenced by the expected result of TestContext2Refresh_targetedCount.
Therefore the signature is changed here, and all of the callers (which,
in retrospect, were all holding a full instance address anyway!) are
updated to that new signature.
The initial rework of this function to support traversals didn't correctly
handle the "all" case, due to a logic error where the ignoreAll branch
could be visited only if ignoreChanges were non-empty, but yet the two
are mutually exclusive in practice.
Now we process ignoreAll separately from ignoreChanges, and invert the
two loops so that we will visit all attributes regardless of what is
in the ignoreChanges slice.
