We recently removed the legacy way we used to track the SHA256 hashes of
individual provider executables as part of a plans.Plan, because these
days we want to track the checksums of entire provider packages rather
than just the executable.
In order to achieve that new goal, we can save a copy of the dependency
lock information inside the plan file. This follows our existing precedent
of using exactly the same serialization formats we'd normally use for
this information, and thus we can reuse the existing models and
serializers and be confident we won't lose any detail in the round-trip.
As of this commit there's not yet anything actually making use of this
mechanism. In a subsequent commit we'll teach the main callers that write
and read plan files to include and expect (respectively) dependency
information, verifying that the available providers still match by the
time we're applying the plan.
Previously the planfile.Create function had accumulated probably already
too many positional arguments, and I'm intending to add another one in
a subsequent commit and so this is preparation to make the callsites more
readable (subjectively) and make it clearer how we can extend this
function's arguments to include further components in a plan file.
There's no difference in observable functionality here. This is just
passing the same set of arguments in a slightly different way.
Historically the responsibility for making sure that all of the available
providers are of suitable versions and match the appropriate checksums has
been split rather inexplicably over multiple different layers, with some
of the checks happening as late as creating a terraform.Context.
We're gradually iterating towards making that all be handled in one place,
but in this step we're just cleaning up some old remnants from the
main "terraform" package, which is now no longer responsible for any
version or checksum verification and instead just assumes it's been
provided with suitable factory functions by its caller.
We do still have a pre-check here to make sure that we at least have a
factory function for each plugin the configuration seems to depend on,
because if we don't do that up front then it ends up getting caught
instead deep inside the Terraform runtime, often inside a concurrent
graph walk and thus it's not deterministic which codepath will happen to
catch it on a particular run.
As of this commit, this actually does leave some holes in our checks: the
command package is using the dependency lock file to make sure we have
exactly the provider packages we expect (exact versions and checksums),
which is the most crucial part, but we don't yet have any spot where
we make sure that the lock file is consistent with the current
configuration, and we are no longer preserving the provider checksums as
part of a saved plan.
Both of those will come in subsequent commits. While it's unusual to have
a series of commits that briefly subtracts functionality and then adds
back in equivalent functionality later, the lock file checking is the only
part that's crucial for security reasons, with everything else mainly just
being to give better feedback when folks seem to be using Terraform
incorrectly. The other bits are therefore mostly cosmetic and okay to be
absent briefly as we work towards a better design that is clearer about
where that responsibility belongs.
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.
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.
Martin Atkins