This is a general catchup of some developments in the HCL2 codebase, but
in particular includes:
- Recording expression and evalcontext as part of diagnostics, so that
variable value information can be included alongside diagnostic
snippets.
- hcldec supports decoding blocks into tuple and object values as well as
list and map values, which then allows cty.DynamicPseudoType nested
attributes to work properly.
These new types are adaptations of terraform.ProviderResolver and
terraform.ResourceProviderFactory respectively. In a later commit we will
update users of the old types to use these new types, possibly in a
"gradual repair" sort of fashion by initially using type aliases, though
that won't 100% solve the problem because the types themselves have
changed in this move to return providers.Interface instead of
terraform.ResourceProvider.
MockProvider and MockProvisioner implement the new plugin interfaces,
and are built following the patterns used by the legacy
MockResourceProvider and MockResourceProvisioner
Close was previously an optional interface, because it's only applicable
on the client side but the types were shared accross all packages. Since
all plugins will now implement Close, it no longer needs to be optional.
Managing which function need to be shared between the terraform plugin
and the helper plugin without creating cycles was becoming difficult.
Move all functions related to converting between terraform and proto
type into plugin/convert.
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.
Our existing core tests make extensive use of the string representation
of a state for comparison purposes, because they were written before we
began making use of helper packages like "cmp".
To avoid the need to rewrite all of those tests and potentially break
them, we will instead port that particular rendering as closely as
possible but mark it with a comment sternly warning not to use it for
anything new.
We don't want to use this moving forward for a number of reasons, but
most notably:
- printing out whole before and after state representations makes it
hard to find a subtle difference in outcome when a test fails, while
"cmp" can provide us with a real diff.
- this string serialization is constrained by the capabilities of
Terraform prior to our new state models, and so it does not
comprehensively represent all possibilities in the new world.
- it will probably behave oddly/poorly when given states containing
features that arrived after it was written, even though I made a
best effort here to make it do something reasonable in situations
I thought about.
The types here were originally written to allow us to defer decoding of
object values until schemas are available, but it turns out that this was
forcing us to defer decoding longer than necessary and potentially decode
the same value multiple times.
To avoid this, we create pairs of types to represent the encoded and
decoded versions and methods for moving between them. These types are
identical to one another apart from how the dynamic values are
represented.
The types here were originally written to allow us to defer decoding of
object values until schemas are available, but it turns out that this was
forcing us to defer decoding longer than necessary and potentially decode
the same value multiple times.
To avoid this, we create pairs of types to represent the encoded and
decoded versions and methods for moving between them. These types are
identical to one another apart from how the dynamic values are
represented.
In practice these pairs of functions are often used together when working
with a "full" statemgr, so these helper wrappers allow us to do that more
conveniently.
This also introduces a new interface statemgr.Storage, which represents
a state manager that has all of the storage capabilities but does not
necessarily support locking. In practice callers will usually just use
statemgr.Full, but these more-specific interfaces allow us to reflect
in APIs which subset of the statemgr functionality each function depends
on.
The new helper/plugin package contains the grpc servers for handling the
new plugin protocol
The GRPCProviderServer and GRPCProvisionerServer handle the grpc plugin
protocol, and convert the requests to the legacy schema.Provider and
schema.Provisioner methods.
Here we add the GRPCProvisioner and GRPCProvider which implement the
core provisioners.Interface and providers.Interface, and translate
betweeen the core types and the grpc protocol.
These will allow easier testing of the grpc endpoints in isolation.
Mocks are generated for ProviderClient, ProvisionerClient,
Provisioner_ProvisionResourceClient, and
Provisioner_ProvisionResourceServer using `go generate`
support the requested platform.
If the newest version of a provider which matches the version
constraints does not support the requested platform, filter the list of
available versions by platform support and try again.
In order to not require state migrations to be supported in both
MigrateState and StateUpgraders, the legacy provider codepath needs to
handle the StateUpgraders transparently during Refresh.
This adds some of the required shim functions to the schema package.
While this further bloats the already huge package, adding the helpers
here was significantly less disruptive than refactoring types into
separate packages to prevent import cycles.
The majority of tests here are directly adapted from existing schema
tests to provide as many known good values to the shims as possible.
It turns out that state upgrades need to be handled differently since
providers are going to be backwards compatible. This means that new
state upgrades may still be stored in the flatmap format when used wih
terraform 0.11. Because we can't account for the specific version which
could produce a legacy state, all future state upgrades need to record
the schema types for decoding.
Rather than defining a single Upgrade function for states, we now have a
list of functions, each of which handle upgrading a specific version to
the next. In practice this isn't much different from the way many
resources implement upgrades themselves, with a separate function for
each version dispatched from the MigrateState function. The only added
burden is the recording of the schema type, and we intend to supply
tools and helper function to prevent the need to copy the entire
existing schema in all cases.
This is the provider-side UpgradeState implementation for a particular
resource. This new function will be called to upgrade a saved state with
an old schema version to the current schema.
UpgradeState also requires a record of the last schema and version that
could have been stored as a flatmapped state. If the stored state is in
the legacy flatmap format, this will allow the provider to properly
decode the flatmapped state into the expected structure for the new json
encoded state. If the stored state's version is below that of the
LegacySchema.Version value, it will first be processed by the legacy
MigrateState function.
Make the function work specifically how we need for RequiresReplace.
Skip index changes, any set changes are only recorded as the set itself,
and filter out duplicate paths.
Add a few more tests to check for various nested structures.
Rather than try and make a generalized path function here, what we
really need in a function to generate the paths needed for
RequiresReplace. This needs to take into account that sets elements
don't need to be indexed themselves, and changes to collection index
values aren't needed.
PathFromFlatmapKey is used to convert a flatmap key to a cty.Path, and
ensures it conforms to the type schema.
This is used when handling Diffs, where the ResourceAttrDiffs are
indexed by the flatmapped key values, and we need to convert those to
addresses to apply to a cty.Value.
Very few resources need connection info, and rather than relying on
providers to set default for some resources, we are going to require
that connection blocks be explicitly set in the configuration.
When creating a flatmap from a cty.Value, there may be Null collections
which don't need to be added to the flatmap at all. Skip over these to
avoid panicking in ElementIterator with a Null value.
Any value that is not set in the configuration should decode as a Null
value. Unknown should still be returned if a computed value expression
is unknown.
Martin Atkins