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 temporarily broken until we implement the new plan file format,
since terraform.Plan is no longer serializable with gob. Rather than have
an error that seems like it needs immediate fixing, we'll be explicit
about it in the error message and focus our efforts on other test failures
for now, and return to implement the new file format later.
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.
Update all references to the version values to use the new package.
The VersionString function was left in the terraform package
specifically for the aws provider, which is vendored. We can remove that
last call once the provider is updated.
When working on an existing plan, the context always used walkApply,
even if the plan was for a full destroy. Mark in the plan if it was
icreated for a destroy, and transfer that to the context when reading
the plan.
Forward-port the plan state check from the 0.9 series.
0.10 has improved the serial handling for the state, so this adds
relevant comments and some more test coverage for the case of an
incrementing serial during apply.
The information stored in a plan is tightly coupled to the Terraform core
and provider plugins that were used to create it, since we have no
mechanism to "upgrade" a plan to reflect schema changes and so mismatching
versions are likely to lead to the "diffs didn't match during apply"
error.
To allow us to catch this early and return an error message that _doesn't_
say it's a bug in Terraform, we'll remember the Terraform version and
plugin binaries that created a particular plan and then require that
those match when loading the plan in order to apply it.
The planFormatVersion is increased here so that plan files produced by
earlier Terraform versions _without_ this information won't be accepted
by this new version, and also that older versions won't try to process
plans created by newer versions.
This is the first step in allowing overrides of map and list variables.
We convert Context.variables to map[string]interface{} from
map[string]string and fix up all the call sites.
This adds a field terraform_version to the state that represents the
Terraform version that wrote that state. If Terraform encounters a state
written by a future version, it will error. You must use at least the
version that wrote that state.
Internally we have fields to override this behavior (StateFutureAllowed),
but I chose not to expose them as CLI flags, since the user can just
modify the state directly. This is tricky, but should be tricky to
represent the horrible disaster that can happen by enabling it.
We didn't have to bump the state format version since the absense of the
field means it was written by version "0.0.0" which will always be
older. In effect though this change will always apply to version 2 of
the state since it appears in 0.7 which bumped the version for other
purposes.
When a user specifies `-target`s on a `terraform plan` and stores
the resulting diff in a plan file using `-out` - it usually works just
fine since the diff is scoped based on the targets.
When there are tainted resources in the state, however, graph nodes to
destroy them were popping back into the plan when it was being loaded
from a file. This was because Targets weren't being stored in the
Planfile, so Terraform didn't know to filter them out. (In the
non-Planfile scenario, we still had the Targets loaded directly from the
flags.)
By encoding Targets in with the Planfile we can ensure that the same
filters are always applied.
Backwards compatibility should be fine here, since we're just adding a
field. The gob encoder/decoder will just do the right thing (ignore/skip
the field) with planfiles stored w/ versions that don't know about
Targets.
Fixes#5183
Add `-target=resource` flag to core operations, allowing users to
target specific resources in their infrastructure. When `-target` is
used, the operation will only apply to that resource and its
dependencies.
The calculated dependencies are different depending on whether we're
running a normal operation or a `terraform destroy`.
Generally, "dependencies" refers to ancestors: resources falling
_before_ the target in the graph, because their changes are required to
accurately act on the target.
For destroys, "dependencies" are descendents: those resources which fall
_after_ the target. These resources depend on our target, which is going
to be destroyed, so they should also be destroyed.
This is REALLY heavy and would be really hard to maintain any sort
of compatibility with, but it is what we're going to do during dev
initially (if we don't ship with it) in order to just get stuff working.
