This commit extracts the remaining UI logic from the local backend,
and removes access to the direct CLI output. This is replaced with an
instance of a `views.Operation` interface, which codifies the current
requirements for the local backend to interact with the user.
The exception to this at present is interactivity: approving a plan
still depends on the `UIIn` field for the backend. This is out of scope
for this commit and can be revisited separately, at which time the
`UIOut` field can also be removed.
Changes in support of this:
- Some instances of direct error output have been replaced with
diagnostics, most notably in the emergency state backup handler. This
requires reformatting the error messages to allow the diagnostic
renderer to line-wrap them;
- The "in-automation" logic has moved out of the backend and into the
view implementation;
- The plan, apply, refresh, and import commands instantiate a view and
set it on the `backend.Operation` struct, as these are the only code
paths which call the `local.Operation()` method that requires it;
- The show command requires the plan rendering code which is now in the
views package, so there is a stub implementation of a `views.Show`
interface there.
Other refactoring work in support of migrating these commands to the
common views code structure will come in follow-up PRs, at which point
we will be able to remove the UI instances from the unit tests for those
commands.
The warning diag added when refreshing an empty state file was never
rendered, and instead a custom (and incorrect) warning was output to the
UI. This commit fixes the dropped diag and removes the custom warning.
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.
The enhanced backends (local and remote) need to be able to render
diagnostics during operations. Prior to this commit, this functionality
was supported with a per-backend `ShowDiagnostics` function pointer.
In order to allow users of these backends to control how diagnostics are
rendered, this commit moves that function pointer to the `Operation`
type. This means that a diagnostic renderer is configured for each
operation, rather than once per backend initialization.
Some secondary consequences of this change:
- The `ReportResult` method on the backend is now moved to the
`Operation` type, as it needs to access the `ShowDiagnostics` callback
(and nothing else from the backend);
- Tests which assumed that diagnostics would be written to the backend's
`cli.Ui` instance are migrated to using a new record/playback diags
helper function;
- Apply, plan, and refresh commands now pass a pointer to the `Meta`
struct's `showDiagnostics` method.
This commit should not change how Terraform works, and is refactoring in
preparation for more changes which move UI code out of the backend.
* 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.
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.
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.
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".
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.
Moves the nested select statements for backend operations into a single
function. The only difference in this part was that apply called
PersistState, which should be harmless regardless of the type of
operation being run.
If the user wishes to interrupt the running operation, only the first
interrupt was communicated to the operation by canceling the provided
context. A second interrupt would start the shutdown process, but not
communicate this to the running operation. This order of event could
cause partial writes of state.
What would happen is that once the command returns, the plugin system
would stop the provider processes. Once the provider processes dies, all
pending Eval operations would return return with an error, and quickly
cause the operation to complete. Since the backend code didn't know that
the process was shutting down imminently, it would continue by
attempting to write out the last known state. Under the right
conditions, the process would exit part way through the writing of the
state file.
Add Stop and Cancel CancelFuncs to the RunningOperation, to allow it to
easily differentiate between the two signals. The backend will then be
able to detect a shutdown and abort more gracefully.
In order to ensure that the backend is not in the process of writing the
state out, the command will always attempt to wait for the process to
complete after cancellation.
Add fields required to create an appropriate context for all calls to
clistate.Lock.
Add missing checks for Meta.stateLock, where we would attempt to lock,
even if locking should be skipped.
- 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.
This allows a refresh on a non-existent or empty state file. We changed
this in 0.9.0 to error which seemed reasonable but it turns out this
complicates automation that runs refresh since it now needed to
determine if the state file was empty before running.
Its easier to just revert this into a warning with exit code zero.
The reason this changed is because in 0.8.x and earlier, the output
would be simply empty with exit code zero which seemed odd.
Fixes#12174
You're allowed to refresh with a nil module (no configs) as long as you
have state. However, if `-input=true` (default) then this would crash
since the input attempts to read the configs.
The API contract with `terraform.Context` says that the module tree must
be non-nil and loaded. To do this for other commands we create an empty
module tree. We do that here now.
The local backend implementation is an implementation of
backend.Enhanced that recreates all the behavior of the CLI but through
the backend interface.
Alisdair McDiarmid