Replace the graphNodeRoot for the main graph with a nodeCloseModule for
the root module. USe a new transformer as well, so as to not change any
behavior of DynamicExpand graphs.
Closing out the root module like we do with sub modules means we no
longer need the OrphanResourceTransformer, or the NodeDestroyResource.
The old resource destroy logic has mostly moved into the instance nodes,
and the remaining resource node was just for cleanup, which need to be
done again by the module since there isn't always a NodeDestroyResource
to be evaluated.
The more-correct state caused a few tests to fail, which need to be
cleaned up to match the state without empty resource husks.
NodeDestroyResource does not require a provider, and to avoid this a
temporary GraphNodeNoProvider was used to differentiate it from other
resource nodes. We can now de-couple the destroy node from the abstract
resource which was adding the ProvidedBy method, and remove the
NoProvider method.
Use the new addrs type here.
Also remove the uniqueMap from the config transformer. We enforce
uniqueness during config loading, and this is more likely to have false
positives due to stringification than anything.
Make the interface name reflect the new return type of the method.
Remove the confusingly named and unused ResourceAddress method from the
resource nodes as well.
We previously had mechanisms to clean up only individual instance states,
leaving behind empty resource husks in the state after they were all
destroyed.
This takes care of it in the "orphan" case. It does not yet do it in the
"terraform destroy" or "terraform plan -destroy" cases because we don't
have anywhere to record in the plan that we're actually destroying and so
the resource configurations should be ignored and _everything_ should be
cleaned. We'll let the state be not-quite-empty in that case for now,
since it doesn't really hurt; cleaning up orphans is the main case because
the state will live on afterwards and so leftover cruft will accumulate
over the course of many changes.
Due to how often the state and plan types are referenced throughout
Terraform, there isn't a great way to switch them out gradually. As a
consequence, this huge commit gets us from the old world to a _compilable_
new world, but still has a large number of known test failures due to
key functionality being stubbed out.
The stubs here are for anything that interacts with providers, since we
now need to do the follow-up work to similarly replace the old
terraform.ResourceProvider interface with its replacement in the new
"providers" package. That work, along with work to fix the remaining
failing tests, will follow in subsequent commits.
The aim here was to replace all references to terraform.State and its
downstream types with states.State, terraform.Plan with plans.Plan,
state.State with statemgr.State, and switch to the new implementations of
the state and plan file formats. However, due to the number of times those
types are used, this also ended up affecting numerous other parts of core
such as terraform.Hook, the backend.Backend interface, and most of the CLI
commands.
Just as with 5861dbf3fc49b19587a31816eb06f511ab861bb4 before, I apologize
in advance to the person who inevitably just found this huge commit while
spelunking through the commit history.
Due to how deeply the configuration types go into Terraform Core, there
isn't a great way to switch out to HCL2 gradually. As a consequence, this
huge commit gets us from the old state to a _compilable_ new state, but
does not yet attempt to fix any tests and has a number of known missing
parts and bugs. We will continue to iterate on this in forthcoming
commits, heading back towards passing tests and making Terraform
fully-functional again.
The three main goals here are:
- Use the configuration models from the "configs" package instead of the
older models in the "config" package, which is now deprecated and
preserved only to help us write our migration tool.
- Do expression inspection and evaluation using the functionality of the
new "lang" package, instead of the Interpolator type and related
functionality in the main "terraform" package.
- Represent addresses of various objects using types in the addrs package,
rather than hand-constructed strings. This is not critical to support
the above, but was a big help during the implementation of these other
points since it made it much more explicit what kind of address is
expected in each context.
Since our new packages are built to accommodate some future planned
features that are not yet implemented (e.g. the "for_each" argument on
resources, "count"/"for_each" on modules), and since there's still a fair
amount of functionality still using old-style APIs, there is a moderate
amount of shimming here to connect new assumptions with old, hopefully in
a way that makes it easier to find and eliminate these shims later.
I apologize in advance to the person who inevitably just found this huge
commit while spelunking through the commit history.
Init should only _add_ values, not remove them.
During graph execution, there are steps that expect that a state isn't
being actively pruned out from under it. Namely: writing deposed states.
Writing deposed states has no way to handle if a state changes
underneath it because the only way to uniquely identify a deposed state
is its index in the deposed array. When destroying deposed resources, we
set the value to `<nil>`. If the array is pruned before the next deposed
destroy, then the indexes have changed, and this can cause a crash.
This PR does the following (with more details below):
* `init()` no longer prunes.
* `ReadState()` always prunes before returning. I can't think of a
scenario where this is unsafe since generally we can always START
from a pruned state, its just causing problems to prune
mid-execution.
* Exported State APIs updated to be robust against nil ModuleStates.
Instead, I think we should adopt the following semantics for init/prune
in our structures that support it (Diff, for example). By having
consistent semantics around these functions, we can avoid this in the
future and have set expectations working with them.
* `init()` (in anything) will only ever be additive, and won't change
ordering or existing values. It won't remove values.
* `prune()` is destructive, expectedly.
* Functions on a structure must not assume a pruned structure 100% of
the time. They must be robust to handle nils. This is especially
important because in many cases values such as `Modules` in state
are exported so end users can simply modify them outside of the
exported APIs.
This PR may expose us to unknown crashes but I've tried to cover our
cases in exposed APIs by checking for nil.
