In configurations which have already been initialized, updating the
source of a non-root module call to an invalid value could cause a nil
pointer panic. This commit fixes the bug and adds test coverage.
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.
We can no longer be assured that the particular instance of a provider
we are using has had GetProviderSchema called. Always check the
diagnostics even if we're fetching a cached response.
When specifying variable values on the command line, name-value pairs
must be joined with an equals sign, without surrounding spaces.
Previously Terraform would interpret "foo = bar" as assigning the value
" bar" to the variable named "foo ". This is never valid, as variable
names may not include whitespace.
This commit looks for this specific error and returns a diagnostic with
a suggestion for correcting it. We cannot simply trim whitespace,
because it is valid to write "foo= bar" to assign the value " bar" to
the variable "foo", as unlikely as it seems.
When executing an apply with no plan, it's possible for a cancellation
to arrive during the final batch of provider operations, resulting in no
errors in the plan. The run context was next checked during the
confirmation for apply, but in the case of -auto-approve that
confirmation is skipped, resulting in the canceled plan being applied.
Make sure we directly check for cancellation before confirming the plan.
Instances of the same AbsResource may share the same Dependencies, which
could point to the same backing array of values. Since address values
are not pointers, and not meant to be shared, we must copy the value
before sorting the slice in-place. Because individual instances of the
same resource may be encoded to state concurrently, failure to copy the
slice first can result in a data race.
