This early validation uses interpolation of a placeholder value to achieve
some "best effort" validation of the validity of the count attribute.
Since HCL2-specified resources can't be interpolated using the main
interpolator, here we branch and use the HCL2 API to do a
largely-equivalent (though slightly less accurate) check.
In the long run we don't really need this extra check at all, since the
validation walk does a more accurate version of the same thing. However,
we're preserving this for now in the interests of minimizing the amount
of change for the main codepath during our experiment.
At this time we're not ready to refactor the various uses of RawConfig
in Terraform core, so we'll smuggle a HCL2 body within a degenerate
RawConfig object that we can then recognize and unpack once this object
is returned to us in an interpolation call.
Fixes#10715
`config.Merge` was not updated to support a number of new features. This
updates the codepath to merge various fields, including the `terraform`
block which was the issue in #10715.
The `Merge` API is called when an `_override` file is present to _merge_
configurations. Normally configurations are _appended_. Only an override
file triggers a _merge_.
I started working on a generic library to do this automatically awhile
back but never finished it. This might motivate me to do so. In the
interest of getting a fix out though, we'll continue the manual
approach.
This changes the representation of maps in the interpolator from the
dotted flatmap form of a string variable named "var.variablename.key"
per map element to use native HIL maps instead.
This involves porting some of the interpolation functions in order to
keep the tests green, and adding support for map outputs.
There is one backwards incompatibility: as a result of an implementation
detail of maps, one could access an indexed map variable using the
syntax "${var.variablename.key}".
This is no longer possible - instead HIL native syntax -
"${var.variablename["key"]}" must be used. This was previously
documented, (though not heavily used) so it must be noted as a backward
compatibility issue for Terraform 0.7.
hil.Eval() now returns (hil.EvaluationResult, error) instead of (value,
type, error). This commit updates the call sites, but retains all
previous behaviour. Tests are also updated.
Fixes an interpolation race that was occurring when a tainted destroy
node and a primary destroy node both tried to interpolate a computed
count in their config. Since they were sharing a pointer to the _same_
config, depending on how the race played out one of them could catch the
config uninterpolated and would then throw a syntax error.
The `Copy()` tree implemented for this fix can probably be used
elsewhere - basically we should copy the config whenever we drop nodes
into the graph - but for now I'm just applying it to the place that
fixes this bug.
Fixes#4982 - Includes a test covering that race condition.
The render code path in `template_file` was doing unsynchronized access
to a shared mapping of functions in `config.Func`.
This caused a race condition that was most often triggered when a
`template_file` had a `count` of more than one, and expressed itself as
a panic in the plugin followed by a cascade of "unexpected EOF" errors
through the plugin system.
Here, we simply turn the FuncMap from shared state into a generated
value, which avoids the race. We do more re-initialization of the data
structure, but the performance implications are minimal, and we can
always revisit with a perf pass later now that the race is fixed.
This is REALLY heavy and would be really hard to maintain any sort
of compatibility with, but it is what we're going to do during dev
initially (if we don't ship with it) in order to just get stuff working.
Alex Pilon