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.
* unlock the state if Context() has an error, exactly as backend/remote does today
* terraform console and terraform import will exit before unlocking state in case of error in Context()
* responsibility for unlocking state in the local backend is pushed down the stack, out of backend.go and into each individual state operation
* add tests confirming that state is not locked after apply and plan
* backend/local: add checks that the state is unlocked after operations
This adds tests to plan, apply and refresh which validate that the state
is unlocked after all operations, regardless of exit status. I've also
added specific tests that force Context() to fail during each operation
to verify that locking behavior specifically.
* command/console: return in case of errors before trying to unlock remote
state
The remote backend `Context` would exit without an active lock if there
was an error, while the local backend `Context` exited *with* a lock. This
caused a problem in `terraform console`, which would call unlock
regardless of error status.
This commit makes the local and remote backend consistently unlock the
state incase of error, and updates terraform console to check for errors
before trying to unlock the state.
* adding tests for remote and local backends
This includes a new TargetAddrs field on both Run and RunCreateOptions
which we'll use to send resource addresses that were specified using
-target on the CLI command line when using the remote backend.
There were some unrelated upstream breaking changes compared to the last
version we had vendored, so this commit also includes some changes to the
backend/remote package to work with this new API, which now requires the
remote backend to be aware of the remote system's opaque workspace id.
* backend/remote: Filter environment variables when loading context
Following up on #23122, the remote system (Terraform Cloud or
Enterprise) serves environment and Terraform variables using a single
type of object. We only should load Terraform variables into the
Terraform context.
Fixes https://github.com/hashicorp/terraform/issues/23283.
For remote operations, the remote system (Terraform Cloud or Enterprise)
writes the stored variable values into a .tfvars file before running the
remote copy of Terraform CLI.
By contrast, for operations that only run locally (like
"terraform import"), we fetch the stored variable values from the remote
API and add them into the set of available variables directly as part
of creating the local execution context.
Previously in the local-only case we were assuming that all stored
variables are strings, which isn't true: the Terraform Cloud/Enterprise UI
allows users to specify that a particular variable is given as an HCL
expression, in which case the correct behavior is to parse and evaluate
the expression to obtain the final value.
This also addresses a related issue whereby previously we were forcing
all sensitive values to be represented as a special string "<sensitive>".
That leads to type checking errors for any variable specified as having
a type other than string, so instead here we use an unknown value as a
placeholder so that type checking can pass.
Unpopulated sensitive values may cause errors downstream though, so we'll
also produce a warning for each of them to let the user know that those
variables are not available for local-only operations. It's a warning
rather than an error so that operations that don't rely on known values
for those variables can potentially complete successfully.
This can potentially produce errors in situations that would've been
silently ignored before: if a remote variable is marked as being HCL
syntax but is not valid HCL then it will now fail parsing at this early
stage, whereas previously it would've just passed through as a string
and failed only if the operation tried to interpret it as a non-string.
However, in situations like these the remote operations like
"terraform plan" would already have been failing with an equivalent
error message anyway, so it's unlikely that any existing workspace that
is being used for routine operations would have such a broken
configuration.
Alisdair McDiarmid