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.
Always return the entire resource object from
evaluationStateData.GetResource, rather than parsing the references for
individual instances. This allows for later evaluation of resource
indexes so we can return errors when they don't exist, and prevent
errors when short-circuiting around invalid indexes in conditionals.
In order to allow lazy evaluation of resource indexes, we can't index
resources immediately via GetResourceInstance. Change the evaluation to
always return whole Resources via GetResource, and index individual
instances during expression evaluation.
This will allow us to always check for invalid index errors rather than
returning an unknown value and ignoring it during apply.
Fix for a crash during terraform plan: If there is a multi-instance
resource (count > 1) where one of the instances was deleted in the
deployment but was still present in the terraform state,
getResourceInstancesAll crashed.
Check not only for rs.Instances[key] to exist, but also to have a
valid Current pointer.
Earlier on in the v0.12 development cycle we made the decision that the
validation walk should consider input values to always be unknown so that
validation is checking validity for all possible inputs rather than for
a specific set of inputs; checking for a specific set of inputs is the
responsibility of the plan walk.
However, we didn't implement that in the best way: we made the
"terraform validate" command force all of the input variables to unknown
but that was insufficient because it didn't also affect the implicit
validation walk we do as part of "terraform plan" and "terraform apply",
causing those to produce confusingly-different results.
Instead, we'll address the problem directly in the reference resolver code,
ensuring that all variable values will always be treated as an unknown
(of the declared type, so type checking is still possible) during any
validate walk, regardless of which command is running it.
Previously we used the native slash type for the host platform, but that
leads to issues if the same configuration is applied on both Windows and
non-Windows systems.
Since Windows supports slashes and backslashes, we can safely return
always slashes here and require that users combine the result with
subsequent path parts using slashes, like:
"${path.module}/foo/bar"
Previously the above would lead to an error on Windows if path.module
contained any backslashes.
This is not really possible to unit test directly right now since we
always run our tests on Unix systems and filepath.ToSlash is a no-op on
Unix. However, this does include some tests for the basic behavior to
verify that it's not regressed as a result of this change.
This will need to be reported in the changelog as a potential breaking
change, since anyone who was using Terraform _exclusively_ on Windows may
have been using expressions like "${path.module}foo\\bar" which they will
now need to update.
This fixes#14986.
Validate should not require state or changes to be present. Break out
early when using evaluationStateData during walkValidate before checking
state or changes, to prevent errors when indexing resources that haven't
been expanded.
Previously we were making an invalid assumption in evaluating module call
references (like module.foo) that the module must exist, which is
incorrect for that particular case because it's a reference to a child
module, not to an object within the current module.
However, now that we have the mechanism for static validation of
references, we'll deal with this one there so it can be caught sooner.
That then makes the original assumption valid, though for a different
reason.
This is verified by two new context tests for validation:
- TestContext2Validate_invalidModuleRef
- TestContext2Validate_invalidModuleOutputRef
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.
Just as when we resolve single output values we must check to see if there
is a planned new value for an output before using the value in state,
because the planned new value might contain unknowns that can't be
represented directly in the state (and would thus be incorrectly returned
as null).
There are still some errors left, because our expression evaluator now
does more validation than before and so we'll need to (in a subsequent
commit) actually use a fixture configuration for these tests so that the
validations will allow the expressions to be validated.
This inverts the previous logic so that it's the status of an object in
the state that decides whether we'll use its value from the plan. This
fixes the problem that otherwise after we've actually applied the change
the partial planned object will continue to shadow the final object in
state.
Our state models cannot store unknown values (since state only deals with
knowns) and so following the lead of recent similar changes for resource
instances we'll treat the planned changeset as a sort of overlay on the
state, preferring values stored there if present, and then write in basic
planned output changes to the plan when we evaluate them.
We're abusing the plan model a little here: its current design is intended
to lay the groundwork for a future release where output values have a
full lifecycle similar to resource instances where we can properly track
changes during the plan phase, but the rest of Terraform isn't yet ready
for that and so we'll just retain an approximation of the planned action
by only using Create and Destroy actions.
A future release should change this so that output changes can be tracked
accurately using an approach similar to that of resource instances.
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.
Our state representation is not able to preserve unknown values, so it's
not suitable for retaining the transient incomplete values we produce
during planning.
Instead, we'll discard the unknown values when writing to state and have
the expression evaluator prefer an object from the plan where possible.
We still use the shape of the transient state to inform things like the
resource's "each mode", so the plan only masks the object values
themselves.
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.
The "config" package is no longer used and will be removed as part
of the 0.12 release cleanup. Since configschema is part of the
"new world" of configuration modelling, it makes more sense for
it to live as a subdirectory of the newer "configs" package.
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.
We now fetch all of the necessary schemas during context creation, so we
can just thread that repository of schemas through into EvalContext and
Evaluator and access the schemas as needed without any further fetching.
This requires updating a few tests to have a valid Provider address in
their state objects, because we need that in order to trigger the loading
of the relevant schema.
In #14526 we fixed a sticky edge-case where a resource with count = 0 set
won't create its containing module state on apply, and thus when another
expression refers to it we need to deal with that absense.
The original bug fixed by #14526 was actually a nil dereference panic in
this case. Our new HCL2-oriented expression evaluation codepath was, on
the other hand, correctly checking for the nil, but was not taking the
correct action in response to it, leading to the result being an
unexpected unknown value.
Here we replicate the fix to #14526 by behaving as if there are just no
instances present in this case. We achieve this in a slightly different
way here by just creating an empty ModuleState, but the effect is the
same as #14526.
This fixes TestContext2Apply_multiVarMissingState.
A provider's schema is the same regardless of its address in the
config. Key them by type so that an evaluation referencing a provider
from an address not included in the graph can still find the schema.
The evaluate data source was using a guessed provider configuration
address from configuration in this case, but that isn't necessarily
correct since the resource might actually be associated with a config
inherited from a parent module.
We still need to retain that fallback to config because we are sometimes
asked to evaluate when state is incomplete (like in "terraform console"),
but if possible we'll take the stored provider address from the state
and use that, even if the resource is otherwise "pending".
We were previously doing this for all of the reference types except this
one. Now we do it for resources and resource instances too, which both
allows us to produce a proper error message when one is missing (rather
than returning an unknown value) and allows us to properly handle the
case where there are no instances yet present in the state (e.g. because
we're in the validate walk) but "count" isn't set, and so a single
unknown value is expected rather than an empty tuple.
Here we replace the stub implementations in evaluationStateData with real
implementations that are based on their equivalents in the old
Interpolator type.
The behavior here is a little different due to the different semantics
expected under HCL2, but the principle remains the same: the main
references are resolved from the state, using config for validation
in order to produce some helpful error messages.
I took some missteps here while doing the initial refactor for HCL2 types.
This restores the map of maps that retains all of the variable values, and
then makes it available to the evaluator.
Previously our evaluationStateData object was constructed inside
Evaluator.Scope, but this was awkward because all of the fields inside it
need to be populated from BuiltinEvalContext fields, and so the signature
of Evaluator.Scope kept growing new arguments over time.
Instead, we reassign the responsibilities here so that Evaluator.Scope
takes an already-constructed lang.Data, and then teach BuiltinEvalContext
to build this object itself from its own internal values.
Due to how deeply the configuration types go into Terraform Core, there
isn't a great way to switch out to HCL2 gradually. As a consequence, this
huge commit gets us from the old state to a _compilable_ new state, but
does not yet attempt to fix any tests and has a number of known missing
parts and bugs. We will continue to iterate on this in forthcoming
commits, heading back towards passing tests and making Terraform
fully-functional again.
The three main goals here are:
- Use the configuration models from the "configs" package instead of the
older models in the "config" package, which is now deprecated and
preserved only to help us write our migration tool.
- Do expression inspection and evaluation using the functionality of the
new "lang" package, instead of the Interpolator type and related
functionality in the main "terraform" package.
- Represent addresses of various objects using types in the addrs package,
rather than hand-constructed strings. This is not critical to support
the above, but was a big help during the implementation of these other
points since it made it much more explicit what kind of address is
expected in each context.
Since our new packages are built to accommodate some future planned
features that are not yet implemented (e.g. the "for_each" argument on
resources, "count"/"for_each" on modules), and since there's still a fair
amount of functionality still using old-style APIs, there is a moderate
amount of shimming here to connect new assumptions with old, hopefully in
a way that makes it easier to find and eliminate these shims later.
I apologize in advance to the person who inevitably just found this huge
commit while spelunking through the commit history.
