This is a rather-messy, complex change to get the "command" package
building again against the new backend API that was updated for
the new configuration loader.
A lot of this is mechanical rewriting to the new API, but
meta_config.go and meta_backend.go in particular saw some major
changes to interface with the new loader APIs and to deal with
the change in order of steps in the backend API.
Previously the rendered plan output was constructed directly from the
core plan and then annotated with counts derived from the count hook.
At various places we applied little adjustments to deal with the fact that
the user-facing diff model is not identical to the internal diff model,
including the special handling of data source reads and destroys. Since
this logic was just muddled into the rendering code, it behaved
inconsistently with the tally of adds, updates and deletes.
This change reworks the plan formatter so that it happens in two stages:
- First, we produce a specialized Plan object that is tailored for use
in the UI. This applies all the relevant logic to transform the
physical model into the user model.
- Second, we do a straightforward visual rendering of the display-oriented
plan object.
For the moment this is slightly overkill since there's only one rendering
path, but it does give us the benefit of letting the counts be derived
from the same data as the full detailed diff, ensuring that they'll stay
consistent.
Later we may choose to have other UIs for plans, such as a
machine-readable output intended to drive a web UI. In that case, we'd
want the web UI to consume a serialization of the _display-oriented_ plan
so that it doesn't need to re-implement all of these UI special cases.
This introduces to core a new diff action type for "refresh". Currently
this is used _only_ in the UI layer, to represent data source reads.
Later it would be good to use this type for the core diff as well, to
improve consistency, but that is left for another day to keep this change
focused on the UI.
We're shifting terminology from "environment" to "workspace". This takes
care of some of the main internal API surface that was using the old
terminology, though is not intended to be entirely comprehensive and is
mainly just to minimize the amount of confusion for maintainers as we
continue moving towards eliminating the old terminology.
Add Env and SetEnv methods to command.Meta to retrieve the current
environment name inside any command.
Make sure all calls to Backend.State contain an environment name, and
make the package compile against the update backend package.
This means that terraform commands like `plan`, `apply`, `show`, and
`graph` will expand all modules by default.
While modules-as-black-boxes is still very true in the conceptual design
of modules, feedback on this behavior has consistently suggested that
users would prefer to see more verbose output by default.
The `-module-depth` flag and env var are retained to allow output to be
optionally limited / summarized by these commands.
Martin Atkins