This is a replacement declaration for using Terraform Cloud as a remote
backend, leaving the literal backend as an implementation detail and not
a user-level concept.
An earlier commit added logic to decode "moved" blocks and do static
validation of them. Here we now include that result also in modules
produced from those files, which we can then use in Terraform Core to
actually implement the moves.
This also places the feature behind an active experiment keyword called
config_driven_move. For now activating this doesn't actually achieve
anything except let you include moved blocks that Terraform will summarily
ignore, but we'll expand the scope of this in later commits to eventually
reach the point where it's really usable.
This PR adds decoding for the upcoming "moved" blocks in configuration. This code is gated behind an experiment called EverythingIsAPlan, but the experiment is not registered as an active experiment, so it will never run (there is a test in place which will fail if the experiment is ever registered).
This also adds a new function to the Targetable interface, AddrType, to simplifying comparing two addrs.Targetable.
There is some validation missing still: this does not (yet) descend into resources to see if the actual resource types are the same (I've put this off in part because we will eventually need the provider schema to verify aliased resources, so I suspect this validation will have to happen later on).
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.
If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.