The clistate package includes a Locker interface which provides a simple
way for the local backend to lock and unlock state, while providing
feedback to the user if there is a delay while waiting for the lock.
Prior to this commit, the backend was responsible for initializing the
Locker, passing through direct access to the cli.Ui instance.
This structure prevented commands from implementing different
implementations of the state locker UI. In this commit, we:
- Move the responsibility of creating the appropriate Locker to the
source of the Operation;
- Add the ability to set the context for a Locker via a WithContext
method;
- Replace the Locker's cli.Ui and Colorize members with a StateLocker
view;
- Implement views.StateLocker for human-readable UI;
- Update the Locker interface to return detailed diagnostics instead of
errors, reducing its direct interactions with UI;
- Add a Timeout() method on Locker to allow the remote backend to
continue to misuse the -lock-timeout flag to cancel pending runs.
When an Operation is created, the StateLocker field must now be
populated with an implementation of Locker. For situations where locking
is disabled, this can be a no-op locker.
This change has no significant effect on the operation of Terraform,
with the exception of slightly different formatting of errors when state
locking or unlocking fails.
* Return an error on unlock failure
When the lock can't be released return the err even if there is no previous error with the current action. This allows faster failure in CI/CD systems. Without this failure to remove the lock would result in the failure happening on a subsequent plan or apply which slows down the feedback loop in automated systems.
* Update command/clistate/state.go
Accept review suggestion
Co-authored-by: ZymoticB <ZymoticB@users.noreply.github.com>
* add test
Co-authored-by: ZymoticB <ZymoticB@users.noreply.github.com>
Co-authored-by: Kristin Laemmert <mildwonkey@users.noreply.github.com>
Most of the state package has been deprecated by the states package.
This PR replaces all the references to the old state package that
can be done simply - the low-hanging fruit.
* states: move state.Locker to statemgr
The state.Locker interface was a wrapper around a statemgr.Full, so
moving this was relatively straightforward.
* command: remove unnecessary use of state package for writing local terraform state files
* move state.LocalState into terraform package
state.LocalState is responsible for managing terraform.States, so it
made sense (to me) to move it into the terraform package.
* slight change of heart: move state.LocalState into clistate instead of
terraform
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.
Simplify the use of clistate.Lock by creating a clistate.Locker
instance, which stores the context of locking a state, to allow unlock
to be called without knowledge of how the state was locked.
This alows the backend code to bring the needed UI methods to the point
where the state is locked, and still unlock the state from an outer
scope.
Provide a NoopLocker as well, so that callers can always call Unlock
without verifying the status of the lock.
Add the StateLocker field to the backend.Operation, so that the state
lock can be carried between the different function scopes of the backend
code. This will allow the backend context to lock the state before it's
read, while allowing the different operations to unlock the state when
they complete.
- Have the ui Lock helper use state.LockWithContext.
- Rename the message package to clistate, since that's how it's imported
everywhere.
- Use a more idiomatic placement of the Context in the LockWithContext
args.
Alisdair McDiarmid