This unusual situation isn't supposed to arise in normal use, but it can
come up in practice in some edge-case scenarios where Terraform fails in
a severe way during a create_before_destroy.
Some earlier versions of Terraform also had bugs in their handling of
deposed objects, so this may also arise if upgrading from one of those
older versions with some leftover deposed objects in the state.
When changes are made and we failed to upload the state, we should not
try to unlock the workspace. Leaving the workspace locked is a good
indication something went wrong and also prevents other changes from
being applied before the newest state is properly uploaded.
Additionally we now output the lock ID when a lock or force-unlock
action failed.
When failing to write the state, the local backend writes the state to a local file called `errrored.tfstate`. Previously it would do so by creating a new state file which would use a new serial and lineage. By exorting the existing state file and directly assigning the new state, the serial and lineage are preserved.
For users who in previous versions have relied on our lack of checking for
whether variables are declared, they may previously have seen an
overwhelming number of warnings when running Terraform v0.12.
Here we cap that number at three specific warnings and then one general
warning, so we can still give a specific source location for the first
couple (for users who have genuinely made a typo) but summarize away a
large number for those who are seeing this because they've not yet
migrated to using environment variables.
This mirrors the change made for providers, so that default values can
be inserted into the config by the backend implementation. This is only
the interface and method name changes, it does not yet add any default
values.
Previously we checked can-update in order to determine if a user had the
required permissions to apply a run, but that wasn't sufficient. So we
added a new permission, can-queue-apply, that we now use instead.
The handling of slashes was broken around listing workspaces in
workspace_key_prefix. While it worked in most places by splitting an
extra time around the spurious slashes, it failed in the case that the
prefix ended with a slash of its own.
A test was temporarily added to verify that the backend works with the
unusual keys, but rather than risking silent breakage around prefixes
with trailing slashes, we also add validation to prevent users from
entering keys with trailing slashes at all.
Ivan Kalita