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.
The shim layer for the legacy SDK type system is not precise enough to
guarantee it will produce identical results between plan and apply. In
particular, values that are null during plan will often become zero-valued
during apply.
To avoid breaking those existing providers while still allowing us to
introduce this check in the future, we'll introduce a rather-hacky new
flag that allows the legacy SDK to signal that it is the legacy SDK and
thus disable the check.
Once we start phasing out the legacy SDK in favor of one that natively
understands our new type system, we can stop setting this flag and thus
get the additional safety of this check without breaking any
previously-released providers.
No other SDK is permitted to set this flag, and we will remove it if we
ever introduce protocol version 6 in future, assuming that any provider
supporting that protocol will always produce consistent results.
The rest of Terraform is still using uint64 for this in various spots, but
we'll update that gradually later. We use int64 here because that matches
what's used in our protobuf definition, and unsigned integers are not
portable across all of the protobuf target languages anyway.
Change ValidateProviderConfig to PrepareProviderConfig.
Providers have a concept of "required fields with defaults" that that
was handled previously by helper/schema doing input and validation.
Because Input and Validation is mostly now handled by core, the provider
had no way of setting default values for missing required attributes.
To achieve the same behavior with new providers, there will be a
PrepareProviderConfig, which allow for manual validation, as well as
alteration of the config. The provider is free to set whatever
attributes necessary to create a valid config and return it to the
caller. If a new config is returned, it will be used instead of the
original in the subsequent Configure call, however core may still add
missing required values during an optional Input phase.
Close was previously an optional interface, because it's only applicable
on the client side but the types were shared accross all packages. Since
all plugins will now implement Close, it no longer needs to be optional.
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.
Very few resources need connection info, and rather than relying on
providers to set default for some resources, we are going to require
that connection blocks be explicitly set in the configuration.
In order for providers to determine if a computed value was unset in the
configuration, the configuration must be passed along with the prior and
proposed states. Terraform core will still handle the creation of the
ProposedNewState to ensure correctness, but the raw configuration value
will also be supplied for comparison.
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.
The ImportResourceStateResponse command can return mutliple types.
ImportedResource maps the state to the appropriate type name, and also
allows providers to return Private data for each resource.
Martin Atkins