Our reference transformer analyses and our destroy transformer analyses
are built around static (not-yet-expanded) addresses so that they can
correctly handle mixtures of expanded and not-yet-expanded objects in the
same graph.
However, this characteristic also makes them unnecessarily conservative
in their handling of references between resources within different
instances of the same module: we know they can never interact with each
other in practice because the dependencies for all instances of a module
are the same and so one instance cannot possibly depend on another.
As a compromise then, here we introduce a new helper function that can
recognize when a proposed edge is between two resource instances that
belong to different instances of the same module, and thus allow us to
skip actually creating those edges even though our imprecise analyses
believe them to be needed.
As well as significantly reducing the number of edges in situations where
multi-instance resources appear inside multi-instance modules, this also
fixes some potential cycles in situations where a single plan includes
both destroying an instance of a module and creating a new instance of the
same module: the dependencies between the objects in the instance being
destroyed and the objects in the instance being created can, if allowed
to connect, cause Terraform to believe that the create and the destroy
both depend on one another even though there is no need for that to be
true in practice.
This involves a very specialized helper function to encode the situation
where this exception applies. This function has an ugly name to reflect
how specialized it is; it's not intended to be of any use outside of these
three situations in particular.
When the DestroyEdgeTransformer was updated to handle stored
dependencies the addrs.ConfigResource type did not yet exist. The lookup
map keys in the transformer needed to be updated to remove module
indexes.
* terraform: add helper functions for creating test state
testSetResourceInstanceCurrent and testSetResourceInstanceTainted are
wrapper functions around states.Module.SetResourceInstanceCurrent()
used to set a resource in state. They work with current, non-deposed
resources with no dependencies.
testSetResourceInstanceDeposed can be used to set a desosed resource in state.
* terraform: update all tests to use modern providers and state
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.
Previously we fetched schemas during the AttachSchemaTransformer,
potentially multiple times as that was re-run for each graph built. Now
we fetch the schemas just once during context construction, passing that
result into each of the graph builders.
This only addresses the schema accesses during graph construction. We're
still separately loading schemas during the main walk for evaluation
purposes. This will be addressed in a later commit.
These transformers both construct temporary graphs using many of the same
transformers used in the apply graph, and properly doing this now requires
access to the providers and provisioners in order to obtain their schemas.
Along with this, we also update the tests here to use the
simpleMockComponentFactory helper to get a mock provider with a schema
already configured, which means we also need to update the test fixtures
and assertions to use the resource type and attributes defined in that
mock factory.
After the refactoring to integrate HCL2 many of the tests were no longer
using correct types, attribute names, etc.
This is a bulk update of all of the tests to make them compile again, with
minimal changes otherwise. Although the tests now compile, many of them
do not yet pass. The tests will be gradually repaired in subsequent
commits, as we continue to complete the refactoring and retrofit work.
Fixes#10440
This updates the behavior of "apply" resources to depend on the
destroy versions of their dependencies.
We make an exception to this behavior when the "apply" resource is CBD.
This is odd and not 100% correct, but it mimics the behavior of the
legacy graphs and avoids us having to do major core work to support the
100% correct solution.
I'll explain this in examples...
Given the following configuration:
resource "null_resource" "a" {
count = "${var.count}"
}
resource "null_resource" "b" {
triggers { key = "${join(",", null_resource.a.*.id)}" }
}
Assume we've successfully created this configuration with count = 2.
When going from count = 2 to count = 1, `null_resource.b` should wait
for `null_resource.a.1` to destroy.
If it doesn't, then it is a race: depending when we interpolate the
`triggers.key` attribute of `null_resource.b`, we may get 1 value or 2.
If `null_resource.a.1` is destroyed, we'll get 1. Otherwise, we'll get
2. This was the root cause of #10440
In the legacy graphs, `null_resource.b` would depend on the destruction
of any `null_resource.a` (orphans, tainted, anything!). This would
ensure proper ordering. We mimic that behavior here.
The difference is CBD. If `null_resource.b` has CBD enabled, then the
ordering **in the legacy graph** becomes:
1. null_resource.b (create)
2. null_resource.b (destroy)
3. null_resource.a (destroy)
In this case, the update would always have 2 values for `triggers.key`,
even though we were destroying a resource later! This scenario required
two `terraform apply` operations.
This is what the CBD check is for in this PR. We do this to mimic the
behavior of the legacy graph.
The correct solution to do one day is to allow splat references
(`null_resource.a.*.id`) to happen in parallel and only read up to to
the `count` amount in the state. This requires some fairly significant
work close to the 0.8 release date, so we can defer this to later and
adopt the 0.7.x behavior for now.
This fixes: `TestContext2Apply_moduleDestroyOrder`
The new destroy graph wasn't properly creating edges that happened
_through_ an output, it was only created the edges for _direct_
dependents.
To fix this, the DestroyEdgeTransformer now creates the full transitive
list of destroy edges by walking all ancestors. This will create more
edges than are necessary but also will no longer miss resources through
an output.
terraform: more specific resource references
terraform: outputs need to know about the new reference format
terraform: resources w/o a config still have a referencable name
Fixes#9920
This was an issue caught with the shadow graph. Self references in
provisioners were causing a self-edge on destroy apply graphs.
We need to explicitly check that we're not creating an edge to ourself.
This is also how the reference transformer works.
