During the Terraform 0.12 work we briefly had a partial update of the old
Terraform 0.11 (and prior) diff renderer that could work with the new
plan structure, but could produce only partial results.
We switched to the new plan implementation prior to release, but the
"terraform show" command was left calling into the old partial
implementation, and thus produced incomplete results when rendering a
saved plan.
Here we instead use the plan rendering logic from the "terraform plan"
command, making the output of both identical.
Unfortunately, due to the current backend architecture that logic lives
inside the local backend package, and it contains some business logic
around state and schema wrangling that would make it inappropriate to move
wholesale into the command/format package. To allow for a low-risk fix to
the "terraform show" output, here we avoid some more severe refactoring by
just exporting the rendering functionality in a way that allows the
"terraform show" command to call into it.
In future we'd like to move all of the code that actually writes to the
output into the "command" package so that the roles of these components
are better segregated, but that is too big a change to block fixing this
issue.
Terraform Core expects all variables to be set, but for some ancillary
commands it's fine for them to just be set to placeholders because the
variable values themselves are not key to the command's functionality
as long as the terraform.Context is still self-consistent.
For such commands, rather than prompting for interactive input for
required variables we'll just stub them out as unknowns to reflect that
they are placeholders for values that a user would normally need to
provide.
This achieves a similar effect to how these commands behaved before, but
without the tendency to produce a slightly invalid terraform.Context that
would fail in strange ways when asked to run certain operations.
During the 0.12 work we intended to move all of the variable value
collection logic into the UI layer (command package and backend packages)
and present them all together as a unified data structure to Terraform
Core. However, we didn't quite succeed because the interactive prompts
for unset required variables were still being handled _after_ calling
into Terraform Core.
Here we complete that earlier work by moving the interactive prompts for
variables out into the UI layer too, thus allowing us to handle final
validation of the variables all together in one place and do so in the UI
layer where we have the most context still available about where all of
these values are coming from.
This allows us to fix a problem where previously disabling input with
-input=false on the command line could cause Terraform Core to receive an
incomplete set of variable values, and fail with a bad error message.
As a consequence of this refactoring, the scope of terraform.Context.Input
is now reduced to only gathering provider configuration arguments. Ideally
that too would move into the UI layer somehow in a future commit, but
that's a problem for another day.
The documentation for the -target option warns that it's intended for
exceptional circumstances only and not for routine use, but that's not a
very prominent location for that warning and so some users miss it.
Here we make the warning more prominent by including it directly in the
Terraform output when -target is in use. We first warn during planning
that the plan might be incomplete, and then warn again after apply
concludes and direct the user to run "terraform plan" to make sure that
there are no further changes outstanding. The latter message is intended
to reinforce that -target should only be a one-off operation and that you
should always run without it soon after to ensure that the workspace is
left in a consistent, converged state.
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 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.
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.
The init error was output deep in the backend by detecting a
special ResourceProviderError and formatted directly to the CLI.
Create some Diagnostics closer to where the problem is detected, and
passed that back through the normal diagnostic flow. While the output
isn't as nice yet, this restores the helpful error message and makes the
code easier to maintain. Better formatting can be handled later.
We've changed the contract for PlanResourceChange to now require the
provider to populate any default values (including unknowns) it wants to
set for computed arguments, so our mock provider here now needs to be a
little more complex to deal with that.
This fixes several of the tests in this package. A minor change to
TestLocal_applyEmptyDirDestroy was required to make it properly configure
the mock provider so PlanResourceChange can access the schema.
Variables values are marshalled with an explicit type of
cty.DynamicPseudoType, but were being decoded using `Implied Type` to
try and guess the type. This was causing errors because `Implied Type`
does not expect to find a late-bound value.
If an instance object in state has an earlier schema version number then
it is likely that the schema we're holding won't be able to decode the
raw data that is stored. Instead, we must ask the provider to upgrade it
for us first, which might also include translating it from flatmap form
if it was last updated with a Terraform version earlier than v0.12.
This ends up being a "seam" between our use of int64 for schema versions
in the providers package and uint64 everywhere else. We intend to
standardize on int64 everywhere eventually, but for now this remains
consistent with existing usage in each layer to keep the type conversion
noise contained here and avoid mass-updates to other Terraform components
at this time.
This also includes a minor change to the test helpers for the
backend/local package, which were inexplicably setting a SchemaVersion of
1 on the basic test state but setting the mock schema version to zero,
creating an invalid situation where the state would need to be downgraded.
Previously we were fetching these from the provider but then immediately
discarding the version numbers because the schema API had nowhere to put
them.
To avoid a late-breaking change to the internal structure of
terraform.ProviderSchema (which is constructed directly all over the
tests) we're retaining the resource type schemas in a new map alongside
the existing one with the same keys, rather than just switching to
using the providers.Schema struct directly there.
The methods that return resource type schemas now return two arguments,
intentionally creating a little API friction here so each new caller can
be reminded to think about whether they need to do something with the
schema version, though it can be ignored by many callers.
Since this was a breaking change to the Schemas API anyway, this also
fixes another API wart where there was a separate method for fetching
managed vs. data resource types and thus every caller ended up having a
switch statement on "mode". Now we just accept mode as an argument and
do the switch statement within the single SchemaForResourceType method.
In order to support free organizations, we need a way to load the `remote` backend and then, depending on the used offering/plan, enable or disable remote operations.
In other words, we should be able to dynamically fall back to the `local` backend if needed, after first configuring the `remote` backend.
To make this works we need to change the way this was done previously when the env var `TF_FORCE_LOCAL_BACKEND` was set. The clear difference of course being that the env var would be available on startup, while the used offering/plan is only known after being able to connect to TFE.
The changes to how we handle setting the state path on the local backend
broke the heuristic we were using here for detecting migration from one
local backend to another with the same state path, which would by default
end up deleting the state altogether after migration.
We now use the StatePaths method to do this, which takes into account
both the default values and any settings that have been set.
Additionally this addresses a flaw in the old method which could
potentially have deleted all non-default workspace state files if the
"path" setting were changed without also changing the "workspace_dir"
setting. This new approach is conservative because it will preserve all
of the files if any one overlaps.
This was failing because we now handle the settings for the local backend
a little differently as a result of decoding it with the HCL2 machinery.
Specifically, the backend.State* fields are now assumed to be what is
given in configuration, and any CLI overrides are maintained separately
in OverrideState* fields so that they can be imposed "just in time" in
StatePaths.
This is particularly important because OverrideStatePath (when set) is
used regardless of workspace name, while StatePath is a suitable value
only for the "default" workspace, with others needing to be constructed
from StateWorkspaceDir instead.
This work was done against APIs that were already changed in the branch
before work began, and so it doesn't apply to the v0.12 development work.
To allow v0.12 to merge down to master, we'll revert this work out for now
and then re-introduce equivalent functionality in later commits that works
against the new APIs.
There are several steps here and a number of them can include reaching out
to remote servers or executing local processes, so it's helpful to have
some trace logs to better narrow down causes of errors and hangs during
this step.
In earlier refactoring we skipped implementing prior state safety checks,
propagating the target addresses from plan, and verifying that all of
the providers are exactly the same from the plan being created.
This change reinstates those checks, including a new error message for
the "stale plan" situation.
If we don't do this, we can't produce any output when applying a saved
plan file.
Here we also introduce a check to the local backend's ReportResult
function so that it won't panic if CLI init is skipped, although that
will no longer happen in the apply-from-file case due to the change
described in the previous paragraph.
We can't generate a valid plan file without a backend configuration to
write into it, but it's the responsibility of the caller (the command
package) to manage the backend configuration mechanism, so we require it
to tell us what to write here.
This feels a little strange because the backend in principle knows its
own config, but in practice the backend only knows the _processed_ version
of the config, not the raw configuration value that was used to configure
it.
converted the existing testPlanState() from terraform.State to
states.State to fix various plan tests.
reverted the "bandaid" in plans/planfile/tfplan.go - at this moment the
backend tests do not include backend configuration, and so the planfile
package can write the plan file but not read it back in. That will be
revisted in a separate track of work.
I have no confidence in the change to plans/planfile/tfplan.go. The
tests were passing an empty backend config, which planfile was able to
write to a file but not read from the same file. This change let me move
past that and it did not break any tests in the planfile package, but I
am concerned that it introduces undesired behavior.
Martin Atkins