The count for a data resource can potentially depend on a managed resource
that isn't recorded in the state yet, in which case references to it will
always return unknown.
Ideally we'd do the data refreshes during the plan phase as discussed in
#17034, which would avoid this problem by planning the managed resources
in the same walk, but for now we'll just skip refreshing any data
resources with an unknown count during refresh and defer that work to the
apply phase, just as we'd do if there were unknown values in the main
configuration for the data resource.
Make sure that NodeDestroyableDataResource has a ResolvedProvider to
call EvalWriteState. This entails setting the ResolvedProvider in
concreteResourceDestroyable, as well as calling EvalGetProvider in
NodeDestroyableDataResource to load the provider schema.
Even though writing the state for a data destroy node should just be
removing the instance, every instance written sets the Provider for the
entire resource. This means that when scaling back a counted data
source, if the removed instances are written last, the data source will
be missing the provider in the state.
We're now writing the "planned new value" to OutputValue, but the data
resource nodes during refresh need to see the verbatim config value in
order to decide whether read must be deferred to the apply phase, so we'll
optionally export that here too.
This is no longer a call into the provider, since all of the data diff
logic is standard for all data sources anyway. Instead, we just compute
the planned new value and construct a planned change from that as-is.
Previously the provider could, in principle, customize the read diff. In
practice there is no real reason to do that and the existing SDK didn't
pass that possibility through to provider code, so we can safely change
this without impacting provider compatibility.
Chaange ResourceProvider to providers.Interface starting from the
context, and fix all type errors.
This only replaced some of method calls directly applicable to the
providers themselves. The resource methods will follow.
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.
This is a little awkward since we need to instantiate the providers much
earlier than before. To avoid a lot of reshuffling here we just spin each
one up and then immediately shut it down again, letting our existing init
functionality during the graph walk still do the main initialization.
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.
Use the ResourceState.Provider field to store the full name of the
provider used during apply. This field is only used when a resource is
removed from the config, and will allow that resource to be removed by
the exact same provider with which it was created.
Modify the locations which might accept the alue of the
ResourceState.Provider field to detect that the name is resolved.
This turned out to be a big messy commit, since the way providers are
referenced is tightly coupled throughout the code. That starts to unify
how providers are referenced, using the format output node Name method.
Add a new field to the internal resource data types called
ResolvedProvider. This is set by a new setter method SetProvider when a
resource is connected to a provider during graph creation. This allows
us to later lookup the provider instance a resource is connected to,
without requiring it to have the same module path.
The InitProvider context method now takes 2 arguments, one if the
provider type and the second is the full name of the provider. While the
provider type could still be parsed from the full name, this makes it
more explicit and, and changes to the name format won't effect this
code.
Currently, the refresh graph uses the resources from state as a base,
with data sources then layered on. Config is not consulted for resources
and hence new resources that are added with count (or any new resource
from config, for that matter) do not get added to the graph during
refresh.
This is leading to issues with scale in and scale out when the same
value for count is used in both resources, and data sources that may
depend on that resource (and possibly vice versa). While the resources
exist in config and can be used, the fact that ConfigTransformer for
resources is missing means that they don't get added into the graph,
leading to "index out of range" errors and what not.
Further to that, if we add these new resources to the graph for scale
out, considerations need to be taken for scale in as well, which are not
being caught 100% by the current implementation of
NodeRefreshableDataResource. Scale-in resources should be treated as
orphans, which according to the instance-form NodeRefreshableResource
node, should be NodeDestroyableDataResource nodes, but this this logic
is currently not rolled into NodeRefreshableDataResource. This causes
issues on scale-in in the form of race-ish "index out of range" errors
again.
This commit updates the refresh graph so that StateTransformer is no
longer used as the base of the graph. Instead, we add resources from the
state and config in a hybrid fashion:
* First off, resource nodes are added from config, but only if
resources currently exist in state. NodeRefreshableManagedResource
is a new expandable resource node that will expand count and add
orphans from state. Any count-expanded node that has config but no
state is also transformed into a plannable resource, via a new
ResourceRefreshPlannableTransformer.
* The NodeRefreshableDataResource node type will now add count orphans
as NodeDestroyableDataResource nodes. This achieves the same effect
as if the data sources were added by StateTransformer, but ensures
there are no races in the dependency chain, with the added benefit of
directing these nodes straight to the proper
NodeDestroyableDataResource node.
* Finally, config orphans (nodes that don't exist in config anymore
period) are then added, to complete the graph.
This should ensure as much as possible that there is a refresh graph
that best represents both the current state and config with updated
variables and counts.
