It must now provide a basic implementation of plan and apply for its
mock provider, which in this case can just pass through the proposed value
generated by core because there are no computed attributes in this schema.
Previously we used a single plan action "Replace" to represent both the
destroy-before-create and the create-before-destroy variants of replacing.
However, this forces the apply graph builder to jump through a lot of
hoops to figure out which nodes need it forced on and rebuild parts of
the graph to represent that.
If we instead decide between these two cases at plan time, the actual
determination of it is more straightforward because each resource is
represented by only one node in the plan graph, and then we can ensure
we put the right nodes in the graph during DiffTransformer and thus avoid
the logic for dealing with deposed instances being spread across various
different transformers and node types.
As a nice side-effect, this also allows us to show the difference between
destroy-then-create and create-then-destroy in the rendered diff in the
CLI, although this change doesn't fully implement that yet.
For PreApply hook purposes we only actually use the Delete, Create, and
Update actions, because other actions are handled in different ways than
a direct call to ApplyResourceChange.
However, if there's a bug in core that causes it to pass a different
action, it's better for us to mark it as being explicitly unknown in the
UI rather than simply defaulting to "Modifying...", which can thus obscure
the problem and make for a confusing result.
We'll now show an "update" symbol prior to the argument to this synthetic
jsonencode(...) call, for consistency with how we show nested values in
other cases and to attach a verb to any "# forces replacement".
We'll also show a special form in the case where the value seems to differ
only in whitespace, so users can understand what's going on in that
hopefully-rare situation, particularly if those whitespace-only changes
end up forcing us to replace a remote object.
Since our own syntax for primitive values is similar to that of JSON, and
since we permit automatic conversions from number and bool to string, we
must do this special JSON value diff formatting only if the value is a
JSON array or object to avoid confusing results.
Because so far we've not supported dynamically-typed complex data
structures, several providers have used strings containing JSON to stand
in for these.
In order to get a readable diff in those cases, we'll recognize situations
where old and new are both JSON and present a diff of the effective value
of the JSON, using a faux call to the jsonencode(...) function to indicate
when we've done so.
This is a bit of a "cute" heuristic, but is important at least for now
until we can migrate away from that practice of passing large JSON strings
to providers and use dynamically-typed attributes instead.
This extra comment line gives us a place to show the full resource address
(since the block header line only includes type and name) and also allows
us to explain in long form the meaning of the change icon on the following
line.
This is a light adaptation of our earlier prototype of structural diff
rendering, as a starting point for what we'll actually ship. This is not
consistent with the latest mocks, so will need some additional work before
it is ready, but integrating this allows us to at least see the plan
contents while fixing up remaining issues elsewhere.
Previously we just left these out of the plan altogether, but in the new
plan types we intentionally include change information for every resource
instance, even if no changes are actually planned, to allow alternative
plan file viewers to show what isn't changing as well as what is.
This codepath is going to be significantly changed before release to make
it support structural diff of the new data types, but this lets us lean on
the old renderer to produce partial output in the mean time while we
continue to work on getting things working end-to-end after the
considerable refactoring that's been going on.
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.
In order to properly migrate the contents of resource, data, provider and
provisioner blocks we will need the provider's schema in order to
understand what is expected, so we can resolve some ambiguities inherent
in the legacy HCL AST.
This includes an initial prototype of migrating the content of resource
blocks just to verify that the information is being gathered correctly.
As with the rest of the upgrade_native.go file, this will be reorganized
significantly once the basic end-to-end flow is established and we can
see how to organize this code better.
Since the intent of the validate command is to check config validity
regardless of context (input variables, state, etc), we use unknown values
of the requested type here, which will then allow us to complete type
checking against the specified types of the variables without assuming
any particular values.
This is the frontend to the work-in-progress codepath for upgrading the
source code for a module written for Terraform v0.11 or earlier to use
the new syntax and idiom of v0.12.
The underlying upgrade code is not yet complete as of this commit, and
so the command is not yet very useful. We will continue to iterate on
the upgrade code in subsequent commits.
Because we gather together diagnostics from many different parts of the
codebase, the list often ends up being in a non-ideal order. Here we
define a partial ordering for diagnostics that should hopefully make them
easier to scan when many are present, by grouping together diagnostics
that are of the same severity and belong to the same file.
We use sort.Stable here because we have a partial order and so we need
to make sure that diagnostics that do not have a relative ordering will
remain in their original order.
This sorting is applied just in time before rendering the diagnostics
in command.Meta.showDiagnostics.
This doesn't yet include test updates, since there are problems in core
currently blocking these tests from running. The tests will therefore be
updated in a subsequent commit.
Previously we were defaulting the provider configuration selection to a
provider in the root module inferred from the resource type name.
This is close, but not quite right: we need to _start_ with a provider
configuration in the same module as we're importing into, and then our
provider resolution steps during import graph construction will use that
as a starting point for a walk up the tree to find the nearest matching
configuration (which might eventually still be in the root, but not
necessarily).
This now uses the HCL2 parser and evaluator APIs and evaluates in terms
of a new-style *lang.Scope, rather than the old terraform.Interpolator
type that is no longer functional.
The Context.Eval method used here behaves differently than the
Context.Interpolater method used previously: it performs a graph walk
to populate transient values such as input variables, local values, and
output values, and produces its scope in terms of the result of that
graph walk. Because of this, it is a lot more robust than the prior method
when asked to resolve references other than those that are persisted
in the state.
Previously an empty diagnostics would appear as "null" in the JSON output,
since that is how encoding/json serializes a nil slice. It's more
convenient for users of dynamic languages to keep the type consistent
in all cases, since they can then just iterate the list without needing a
special case for when it is null.
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.
For the moment this is just a lightly-adapted copy of
ModuleTreeDependencies named ConfigTreeDependencies, with the goal that
the two can live concurrently for the moment while not all callers are yet
updated and then we can drop ModuleTreeDependencies and its helper
functions altogether in a later commit.
This can then be used to make "terraform init" and "terraform providers"
work properly with the HCL2-powered configuration loader.
This is a rather-messy, complex change to get the "command" package
building again against the new backend API that was updated for
the new configuration loader.
A lot of this is mechanical rewriting to the new API, but
meta_config.go and meta_backend.go in particular saw some major
changes to interface with the new loader APIs and to deal with
the change in order of steps in the backend API.
The new config loader requires some steps to happen in a different
order, particularly in regard to knowing the schema in order to
decode the configuration.
Here we lean directly on the configschema package, rather than
on helper/schema.Backend as before, because it's generally
sufficient for our needs here and this prepares us for the
helper/schema package later moving out into its own repository
to seed a "plugin SDK".
The remote API this talks to will be going away very soon, before our next
major release, and so we'll remove the command altogether in that release.
This also removes the "encodeHCL" function, which was used only for
adding a .tfvars-formatted file to the uploaded archive.
In the long run we'd like to offer machine-readable output for more
commands, but for now we'll just start with a tactical feature in
"terraform validate" since this is useful for automated testing scenarios,
editor integrations, etc, and doesn't include any representations of types
that are expected to have breaking changes in the near future.
As part of some light reorganization of our commands, this new
implementation no longer does validation of variables and will thus avoid
the need to spin up a fully-valid context. Instead, its focus is on
validating the configuration itself, regardless of any variables, state,
etc.
This change anticipates us later adding a -validate-only flag to
"terraform plan" which will then take over the related use-case of
checking if a particular execution of Terraform is valid, _including_ the
state, variables, etc.
Although leaving variables out of validate feels pretty arbitrary today
while all of the variable sources are local anyway, we have plans to
allow per-workspace variables to be stored in the backend in future and
at that point it will no longer be possible to fully validate variables
without accessing the backend. The "terraform plan" command explicitly
requires access to the backend, while "terraform validate" is now
explicitly for local-only validation of a single module.
In a future commit this will be extended to do basic type checking of
the configuration based on provider schemas, etc.
We need to share a single config loader across all callers because that
allows us to maintain the source code cache we'll use for snippets in
error messages.
Nothing calls this yet. Callers will be gradually updated away from Module
and Config in subsequent commits.
If we get a diagnostic message that references a source range, and if the
source code for the referenced file is available, we'll show a snippet of
the source code with the source range highlighted.
At the moment we have no cache of source code, so in practice this
codepath can never be visited. Callers to format.Diagnostic will be
gradually updated in subsequent commits.
In some cases this is needed to keep the UX clean and to make sure any remote exit codes are passed through to the local process.
The most obvious example for this is when using the "remote" backend. This backend runs Terraform remotely and stream the output back to the local terminal.
When an error occurs during the remote execution, all the needed error information will already be in the streamed output. So if we then return an error ourselves, users will get the same errors twice.
By allowing the backend to specify the correct exit code, the UX remains the same while preserving the correct exit codes.
Martin Atkins