Commit Graph

5 Commits

Author SHA1 Message Date
Martin Atkins bee7403f3e command/workspace_delete: Allow deleting a workspace with empty husks
Previously we would reject attempts to delete a workspace if its state
contained any resources at all, even if none of the resources had any
resource instance objects associated with it.

Nowadays there isn't any situation where the normal Terraform workflow
will leave behind resource husks, and so this isn't as problematic as it
might've been in the v0.12 era, but nonetheless what we actually care
about for this check is whether there might be any remote objects that
this state is tracking, and for that it's more precise to look for
non-nil resource instance objects, rather than whole resources.

This also includes some adjustments to our error messaging to give more
information about the problem and to use terminology more consistent with
how we currently talk about this situation in our documentation and
elsewhere in the UI.

We were also using the old State.HasResources method as part of some of
our tests. I considered preserving it to avoid changing the behavior of
those tests, but the new check seemed close enough to the intent of those
tests that it wasn't worth maintaining this method that wouldn't be used
in any main code anymore. I've therefore updated those tests to use
the new HasResourceInstanceObjects method instead.
2021-10-13 13:54:11 -07:00
Martin Atkins 89b05050ec core: Functional-style API for terraform.Context
Previously terraform.Context was built in an unfortunate way where all of
the data was provided up front in terraform.NewContext and then mutated
directly by subsequent operations. That made the data flow hard to follow,
commonly leading to bugs, and also meant that we were forced to take
various actions too early in terraform.NewContext, rather than waiting
until a more appropriate time during an operation.

This (enormous) commit changes terraform.Context so that its fields are
broadly just unchanging data about the execution context (current
workspace name, available plugins, etc) whereas the main data Terraform
works with arrives via individual method arguments and is returned in
return values.

Specifically, this means that terraform.Context no longer "has-a" config,
state, and "planned changes", instead holding on to those only temporarily
during an operation. The caller is responsible for propagating the outcome
of one step into the next step so that the data flow between operations is
actually visible.

However, since that's a change to the main entry points in the "terraform"
package, this commit also touches every file in the codebase which
interacted with those APIs. Most of the noise here is in updating tests
to take the same actions using the new API style, but this also affects
the main-code callers in the backends and in the command package.

My goal here was to refactor without changing observable behavior, but in
practice there are a couple externally-visible behavior variations here
that seemed okay in service of the broader goal:
 - The "terraform graph" command is no longer hooked directly into the
   core graph builders, because that's no longer part of the public API.
   However, I did include a couple new Context functions whose contract
   is to produce a UI-oriented graph, and _for now_ those continue to
   return the physical graph we use for those operations. There's no
   exported API for generating the "validate" and "eval" graphs, because
   neither is particularly interesting in its own right, and so
   "terraform graph" no longer supports those graph types.
 - terraform.NewContext no longer has the responsibility for collecting
   all of the provider schemas up front. Instead, we wait until we need
   them. However, that means that some of our error messages now have a
   slightly different shape due to unwinding through a differently-shaped
   call stack. As of this commit we also end up reloading the schemas
   multiple times in some cases, which is functionally acceptable but
   likely represents a performance regression. I intend to rework this to
   use caching, but I'm saving that for a later commit because this one is
   big enough already.

The proximal reason for this change is to resolve the chicken/egg problem
whereby there was previously no single point where we could apply "moved"
statements to the previous run state before creating a plan. With this
change in place, we can now do that as part of Context.Plan, prior to
forking the input state into the three separate state artifacts we use
during planning.

However, this is at least the third project in a row where the previous
API design led to piling more functionality into terraform.NewContext and
then working around the incorrect order of operations that produces, so
I intend that by paying the cost/risk of this large diff now we can in
turn reduce the cost/risk of future projects that relate to our main
workflow actions.
2021-08-30 13:59:14 -07:00
Martin Atkins f40800b3a4 Move states/ to internal/states/
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.

If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
2021-05-17 14:09:07 -07:00
Martin Atkins 05caff2ca3 Move tfdiags/ to internal/tfdiags/
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.

If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
2021-05-17 14:09:07 -07:00
Martin Atkins 73dda868cc Move backend/ to internal/backend/
This is part of a general effort to move all of Terraform's non-library
package surface under internal in order to reinforce that these are for
internal use within Terraform only.

If you were previously importing packages under this prefix into an
external codebase, you could pin to an earlier release tag as an interim
solution until you've make a plan to achieve the same functionality some
other way.
2021-05-17 14:09:07 -07:00