terraform/internal/command/jsonstate
Martin Atkins b0b8d4aa6f states: Only track root module output values
For a very long time we've had an annoying discrepancy between the
in-memory state model and our state snapshot format where the in-memory
format stores output values for all modules whereas the snapshot format
only tracks the root module output values because those are all we
actually need to preserve between runs.

That design wart was a result of us using the state both as an internal
and an external artifact, due to having nowhere else to store the
transient values of non-root module output values while Terraform Core
does its work.

We now have namedvals.State to internally track all of the throwaway
results from named values that don't need to persist between runs, so now
we'll use that for our internal work instead and reserve the states.State
model only for the data that we will preserve between runs in state
snapshots.

The namedvals internal model isn't really designed to support enumerating
all of the output values for a particular module call, but our expression
evaluator currently depends on being able to do that and so we have a
temporary inefficient implementation of that which just scans the entire
table of values as a stopgap just to avoid this commit growing even larger
than it already is. In a future commit we'll rework the evaluator to
support the PartialEval mode and at the same time move the responsiblity
for enumerating all of the output values into the evaluator itself, since
it should be able to determine what it's expecting by analyzing the
configuration rather than just by trusting that earlier evaluation has
completed correctly.

Because our legacy state string serialization previously included output
values for all modules, some of our context tests were accidentally
depending on the implementation detail of how those got stored internally.
Those tests are updated here to test only the data that is a real part
of Terraform Core's result, by ensuring that the relevant data appears
somewhere either in a root output value or in a resource attribute.
2023-12-07 09:56:36 -08:00
..
doc.go Update copyright file headers to BUSL-1.1 2023-08-10 23:43:27 +01:00
state.go states: Only track root module output values 2023-12-07 09:56:36 -08:00
state_test.go Update copyright file headers to BUSL-1.1 2023-08-10 23:43:27 +01:00