5417975946 addressed a regression in the
logic for catching when the newer module meta-arguments are used in
conjunction with the legacy practice of including provider configurations
inside modules, where the check started incorrectly catching situations
where the legacy nested provider configuration was in the same module
as the child call using one of those meta-arguments.
This is a regression test to catch if a similar bug arises in the future.
Since it's testing validation rules that apply to an entire configuration
tree, it ended up in a rather idiosyncratic location under the "configload"
package, rather than directly in "configs". The "configs" package only
knows how to load one module at a time, so it's harder to write a test
like this in that context. Due to it being further removed from the code
it is testing, I included a test for the correct error too in order to
increase the chance that we'll learn if future changes in the "configs"
package invalidate this regression test.
I've verified that this new test fails without the change made in the
earlier commit.
This fixes a bug introduced in 1879a39 in which initialising a module will fail
if that module contains both a provider block and a module call using for_each.
The version that was in use previously broke my runs with a nice `ssh:
handshake failed: agent unsupported algorithm "ssh-ed25519"` error. I
took a further look into this, and saw that the change that broke ssh
for me was fixed in https://github.com/golang/crypto/commit/46612604a.
Yay!
When a data resource is used for the purposes of verifying a condition
about an object managed elsewhere (e.g. if the managed resource doesn't
directly export all of the information required for the condition) it's
important that we defer the data resource read to the apply step if the
corresponding managed resource has any changes pending.
Typically we'd expect that to come "for free" but unfortunately we have
a pragmatic special case in our handling of data resources where we
normally defer to the apply step only if a _direct_ dependency of the data
resource has a change pending, and allow a plan-time read if there's
a pending change in an indirect dependency. This allowed us to preserve
some compatibility with the questionable historical behavior of always
reading data resources proactively unless the configuration contains
unknown values, since the arguably-more-correct behavior would've been a
regression for anyone who had been depending on that before.
Since preconditions and postconditions didn't exist until now, we are not
constrained in the same way by backward compatibility, and so we can adopt
the more correct behavior in the case where a data resource has conditions
specified. This does unfortunately make the handling of data resources
with conditions subtly inconsistent with those that don't, but this is
a better situation than the alternative where it would be easy to get into
a trapped situation where the remote system is invalid and it's impossible
to plan the change that would make it valid again because the conditions
evaluate too soon, prior to the fix being applied.
We have two different reasons why a data resource might be read only
during apply, rather than during planning as usual: the configuration
contains unknown values, or the data resource as a whole depends on a
managed resource which itself has a change pending.
However, we didn't previously distinguish these two in a way that allowed
the UI to describe the difference, and so we confusingly reported both
as "config refers to values not yet known", which in turn led to a number
of reasonable questions about why Terraform was claiming that but then
immediately below showing the configuration entirely known.
Now we'll use our existing "ActionReason" mechanism to tell the UI layer
which of the two reasons applies to a particular data resource instance.
The "dependency pending" situation tends to happen in conjunction with
"config unknown", so we'll prefer to refer that the configuration is
unknown if both are true.
