As the Graph is walked, the current way to set the context path was to
have the walker return a context from EnterPath. This required that
every node know it's absolute path, which can no longer be the case
during plan when modules have not been expanded.
This introduces a new method called WithPath, which returns a copy of
the context with the internal path updated to reflect the method
argument. Any use of the EvalContext that requires knowing the path will
now panic if it wasn't explicitly set to ensure that evaluations always
occur in the correct path.
Add EvalContext to the GraphWalker interface.
EvalContext returns an EvalContext that has not yet set a path. This
will allow us to enforce that all context operations requiring a module
instance path will require that a path be explicitly set rather than
evaluating within the wrong path.
This is not used yet, but in future commits will be used as a
"blackboard" to centrally aggregate the information pertaining to
expansion of resources and modules (using "count" or "for_each") to help
ensure consistent treatment of the expansion process during a graph walk.
In practice this only really makes sense for the plan walk, because the
apply walk doesn't do any dynamic expansion.
Our state representation is not able to preserve unknown values, so it's
not suitable for retaining the transient incomplete values we produce
during planning.
Instead, we'll discard the unknown values when writing to state and have
the expression evaluator prefer an object from the plan where possible.
We still use the shape of the transient state to inform things like the
resource's "each mode", so the plan only masks the object values
themselves.
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.
The "config" package is no longer used and will be removed as part
of the 0.12 release cleanup. Since configschema is part of the
"new world" of configuration modelling, it makes more sense for
it to live as a subdirectory of the newer "configs" package.
We now fetch all of the necessary schemas during context creation, so we
can just thread that repository of schemas through into EvalContext and
Evaluator and access the schemas as needed without any further fetching.
This requires updating a few tests to have a valid Provider address in
their state objects, because we need that in order to trigger the loading
of the relevant schema.
To avoid a massively-disruptive change to how EvalNode works, we're now
"smuggling" warnings through the error return value for these, but this
depends on all of the Eval machinery correctly handling this special case
and continuing evaluation when only warnings are returned.
Previous changes missed EvalSequence as a place where execution halts on
error. Now it will accumulate diagnostics itself, aborting if any of
them are error diagnostics, and then wrap its own result up in an error
to be returned by the main Eval function, which already treats non-fatal
errors as a special case, though now produces an explicit log message
about that situation to make it easier to spot in trace logs.
This also includes a more detailed warning message for the warning about
provider input being disabled. While this warning should be removed before
we release anyway, having this additional detail is helpful in debugging
tests where it's being returned.
I took some missteps here while doing the initial refactor for HCL2 types.
This restores the map of maps that retains all of the variable values, and
then makes it available to the evaluator.
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 configured providers directly, rather than looking for inherited
provider configuration during graph evaluation.
First remove the provider config cache, and the associated
SetProviderConfig and ParentProviderConfig methods on the eval context.
Every provider must be configured, so there's no need to look for
configuration from other provider instances.
The config.ProviderConfig struct now has a Scope field which stores the
proper path for the interpolation scope. To get this metadata to the
interpolator, we add an EvalInterpolatProvider node which can carry the
ProviderConfig, and an InterpolateProvider context method to carry the
ProviderConfig.Scope into the InterplationScope.
Some of the tests could be adjusted to account for the new inheritance
behavior, and some were simply no longer valid and will be removed.
The remaining tests have questions on how they should work in practice.
This mostly concerns orphaned modules where there is no longer a way to
obtain a provider. In some cases we may require that a minimal provider
config be present to handle the destroy process, but we need further
testing.
All disabled code was commented out in this commit to record any
additional comments. The following commit will be a cleanup pass.
This switches to the Go "context" package for cancellation and threads
the context through all the way to evaluation to allow behavior based on
stopping deep within graph execution.
This also adds the Stop API to provisioners so they can quickly exit
when stop is called.
Implement debugInfo and the DebugGraph
DebugInfo will be a global variable through which graph debug
information can we written to a compressed archive. The DebugInfo
methods are all safe for concurrent use, and noop with a nil receiver.
The API outside of the terraform package will be to call SetDebugInfo
to create the archive, and CloseDebugInfo() to properly close the file.
Each write to the archive will be flushed and sync'ed individually, so
in the event of a crash or a missing call to Close, the archive can
still be recovered.
The DebugGraph is a representation of a terraform Graph to be written to
the debug archive, currently in dot format. The DebugGraph also contains
an internal buffer with Printf and Write methods to add to this buffer.
The buffer will be written to an accompanying file in the debug archive
along with the graph.
This also adds a GraphNodeDebugger interface. Any node implementing
`NodeDebug() string` can output information to annotate the debug graph
node, and add the data to the log. This interface may change or be
removed to provide richer options for debugging graph nodes.
The new graph builders all delegate the build to the BasicGraphBuilder.
Having a Name field lets us differentiate the actual builder
implementation in the debug graphs.
This is necessary so that the shadow version can actually keep track of
what provider is used for what. Before, providers for different alises
were just initialized but the factory had no idea. Arguably this is fine
but when trying to build a shadow graph this presents challenges.
With these changes, we now pass an opaque "uid" through that is used to
keep track of the providers and what real maps to what shadow.
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.
The ContextGraphWalker struct includes a lock that's passed down to
BuiltinEvalContext and guards access to interpolation variables as
they're written using SetVariables.
The likely problem being expressed in #5733 is that the same map
reference is also passed down to the Interpolater.Variables field, which
is used for variable lookup.
Here, we plumb the same lock we're using to guard access for writes down
and acquire it before doing variable reads as well. It's not as fine
grained as perhaps it could be, but all the context tests pass and I
believe this should address #5733.
