The API surface area is much smaller when we use the remote backend for remote state only.
So in order to try and prevent any backwards incompatibilities when TF runs inside of TFE, we’ve split up the discovery services into `state.v2` (which can be used for remote state only configurations, so when running in TFE) and `tfe.v2.1` (which can be used for all remote configurations).
The go-getter library that is used by the module loader validates S3 URLs in the parseURL function. That function assumes path-style URLs and fails on virtual-hosted-style URLs.
Our usual "ground rules" for mapping configschema to cty call for the
collection values representing nested block types to always be known and
non-null, using an empty collection to represent the absense of any blocks
of that type so that users can always safely use length(...) etc on them
without worrying about them sometimes being null.
However, due to some different behaviors in the legacy SDK we've allowed
it an exception to this rule which means that we can see unknown and null
collections in these positions in object values returned from provider
operations like PlanResourceChange and ApplyResourceChange when the legacy
SDK opt-out is activated.
As a consequence of this, we need to be mindful in our safety check
functions, like AssertObjectCompatible here, of tolerating these non-ideal
situations to allow the safety checks to complete. We run these checks
even when the provider requests an opt-out, because we want to note any
inconsistencies as WARNING level log lines to aid in debugging.
cty.Value.AsValueMap can return nil if called on an empty map or object.
The logic above was dealing with that case for maps, but object types
were falling through into this codepath and panicking when trying to
assign a new key into the nil dstMap.
This also includes a bonus fix where we were calling ty.ElementType in
a switch case that accepts object types. Object types don't have a single
element type, so we can't call ElementType on those (that also panics)
but we _can_ use the type of the value we selected from src to construct
our placeholder null value.
A provider may react to a create or update failing by returning error
diagnostics and a partially-updated or nil new value, in which case we
do not expect our AssertObjectCompatible consistency check to succeed: the
provider is just assumed to be doing the best it can to preserve whatever
partial outcome it was able to achieve.
However, if errors are accompanied with a nil new value after an update,
we'll assume that the provider is telling us it wasn't able to get far
enough to make any change at all, and so we'll retain the prior value in
state. This ensures that a provider can't cause an object to be forgotten
from the state just because an update failed.
* command/jsonconfig: display module variables in config output
The tests have been updated to reflect this change.
* command/jsonconfig: properly handle variables with nil defaults
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.
Now that we're actually verifying correct behavior of providers during
plan and apply, our mock providers need to behave like real providers,
properly propagating any configured values through the plan and into the
final state.
For most of these it was simpler to just switch over to using the newer
PlanResourceChangeFn mock interface, away from the legacy DiffFn approach,
because then we can just return the ProposedNewState verbatim because our
schema for these tests does not require any default values to be
populated.
Prior to Terraform 0.12 there were certain behaviors we expected from
providers that were actually just details of the SDK and not part of the
enforced contract.
For 0.12 we're now codifying some of these behaviors explicitly via safety
checks in core, thus ensuring that all future providers will behave in a
consistent way that users can rely on.
Unfortunately, due to the hand-written nature of the mock provider
implementations we use in tests, they have been getting away with some
unusual behaviors that don't match our usual expectations, and our safety
checks now detect those as incorrect behaviors.
To address this, we make the minimal changes to each test to ensure that
its mock provider behaves in a consistent way, which requires that values
set in config be represented correctly in the plan and ultimately saved
in the new state, without any changes along the way. In particular, the
common testDiffFn implementation has historically used a number of special
hidden attributes to trigger special behaviors, and our new rules require
that these special settings propagate properly through the plan and into
the state.
Sander van Harmelen