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.
Validation is the best time to return detailed diagnostics
to the user since we're much more likely to have source
location information, etc than we are in later operations.
This change doesn't actually add any detail to the messages
yet, but it changes the interface so that we can gradually
introduce more detailed diagnostics over time.
While here there are some minor adjustments to some of the
messages to improve their consistency with terminology we
use elsewhere.
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.
During plan and apply, because the provider constraints need to be built
from a plan, they are not checked until the terraform.Context is
created. Since the context is always requested by the backend during the
Operation, the backend needs to be responsible for generating contextual
error messages for the user.
Instead of formatting the ResolveProviders errors during NewContext,
return a special error type, ResourceProviderError to signal that
init will be required. The backend can then extract and format the
errors.
Fixes#11628
This is a simple fix to output warnings. I originally forgot to do this
since the local backend didn't have a CLI UI at the time. It does now so
this is an easy fix.
The local backend implementation is an implementation of
backend.Enhanced that recreates all the behavior of the CLI but through
the backend interface.
Sander van Harmelen