When rendering a diff between current state and projected state, we only
show resources and outputs which have changes. However, we show a full
structural diff for these values, which includes all attributes and
blocks for a changed resource or output. The result can be a very long
diff, which makes it difficult to verify what the changed fields are.
This commit adds an experimental concise diff renderer, which suppresses
most unchanged fields, only displaying the most relevant changes and
some identifying context. This means:
- Always show all identifying attributes, initially defined as `id`,
`name`, and `tags`, even if unchanged;
- Only show changed, added, or removed primitive values: `string`,
`number`, or `bool`;
- Only show added or removed elements in unordered collections and
structural types: `map`, `set`, and `object`;
- Show added or removed elements with any surrounding unchanged elements
for sequence types: `list` and `tuple`;
- Only show added or removed nested blocks, or blocks with changed
attributes.
If any attributes, collection elements, or blocks are hidden, a count
is kept and displayed at the end of the parent scope. This ensures that
it is clear that the diff is only displaying a subset of the resource.
The experiment is currently enabled by default, but can be disabled by
setting the TF_X_CONCISE_DIFF environment variable to 0.
Most of the functionality for rendering output changes is covered by the
tests for ResourceChanges, as they both share the same diff renderer.
This commit adds a few tests to cover some of the output specific code.
a large refactor to addrs.AbsProviderConfig, embedding the addrs.Provider instead of a Type string. I've added and updated tests, added some Legacy functions to support older state formats and shims, and added a normalization step when reading v4 (current) state files (not the added tests under states/statefile/roundtrip which work with both current and legacy-style AbsProviderConfig strings).
The remaining 'fixme' and 'todo' comments are mostly going to be addressed in a subsequent PR and involve looking up a given local provider config's FQN. This is fine for now as we are only working with default assumption.
* Introduce "Local" terminology for non-absolute provider config addresses
In a future change AbsProviderConfig and LocalProviderConfig are going to
become two entirely distinct types, rather than Abs embedding Local as
written here. This naming change is in preparation for that subsequent
work, which will also include introducing a new "ProviderConfig" type
that is an interface that AbsProviderConfig and LocalProviderConfig both
implement.
This is intended to be largely just a naming change to get started, so
we can deal with all of the messy renaming. However, this did also require
a slight change in modeling where the Resource.DefaultProviderConfig
method has become Resource.DefaultProvider returning a Provider address
directly, because this method doesn't have enough information to construct
a true and accurate LocalProviderConfig -- it would need to refer to the
configuration to know what this module is calling the provider it has
selected.
In order to leave a trail to follow for subsequent work, all of the
changes here are intended to ensure that remaining work will become
obvious via compile-time errors when all of the following changes happen:
- The concept of "legacy" provider addresses is removed from the addrs
package, including removing addrs.NewLegacyProvider and
addrs.Provider.LegacyString.
- addrs.AbsProviderConfig stops having addrs.LocalProviderConfig embedded
in it and has an addrs.Provider and a string alias directly instead.
- The provider-schema-handling parts of Terraform core are updated to
work with addrs.Provider to identify providers, rather than legacy
strings.
In particular, there are still several codepaths here making legacy
provider address assumptions (in order to limit the scope of this change)
but I've made sure each one is doing something that relies on at least
one of the above changes not having been made yet.
* addrs: ProviderConfig interface
In a (very) few special situations in the main "terraform" package we need
to make runtime decisions about whether a provider config is absolute
or local.
We currently do that by exploiting the fact that AbsProviderConfig has
LocalProviderConfig nested inside of it and so in the local case we can
just ignore the wrapping AbsProviderConfig and use the embedded value.
In a future change we'll be moving away from that embedding and making
these two types distinct in order to represent that mapping between them
requires consulting a lookup table in the configuration, and so here we
introduce a new interface type ProviderConfig that can represent either
AbsProviderConfig or LocalProviderConfig decided dynamically at runtime.
This also includes the Config.ResolveAbsProviderAddr method that will
eventually be responsible for that local-to-absolute translation, so
that callers with access to the configuration can normalize to an
addrs.AbsProviderConfig given a non-nil addrs.ProviderConfig. That's
currently unused because existing callers are still relying on the
simplistic structural transform, but we'll switch them over in a later
commit.
* rename LocalType to LocalName
Co-authored-by: Kristin Laemmert <mildwonkey@users.noreply.github.com>
* huge change to weave new addrs.Provider into addrs.ProviderConfig
* terraform: do not include an empty string in the returned Providers /
Provisioners
- Fixed a minor bug where results included an extra empty string
We have a special treatment for multi-line strings that are being updated
in-place where we show them across multiple lines in the plan output, but
we didn't use that same treatment for rendering multi-line strings in
isolation such as when they are being added for the first time.
Here we detect when we're rendering a multi-line string in a no-change
situation and render it using the diff renderer instead, using the same
value for old and new and thus producing a multi-line result without any
diff markers at all.
This improves consistency between the change and no-change cases, and
makes multi-line strings (such as YAML in block mode) readable in all
cases.
cty now guarantees that sets of primitive values will iterate in a
reasonable order. Previously it was the caller's responsibility to deal
with that, but we invariably neglected to do so, causing inconsistent
ordering. Since cty prioritizes consistent behavior over performance, it
now imposes its own sort on set elements as part of iterating over them so
that calling applications don't have to worry so much about it.
This change also causes cty to consistently push unknown and null values
in sets to the end of iteration, where before that was undefined. This
means that our diff output will now consistently list additions before
removals when showing sets, rather than the ordering being undefined as
before.
The ordering of known, non-null, non-primitive values is still not
contractually fixed but remains consistent for a particular version of
cty.
When rendering the diff, the NoOp changes should come from the LCS
sequence, rather than the new sequence. The two indexes will not align
in many cases, adding the wrong new object or indexing out of bounds.
Due to these tests happening in the wrong order, removing an object from
the end of a sequence of objects would previously cause a bounds-check
panic.
Rather than a more severe rework of the logic here, for now we'll just
introduce an extra precondition to prevent the panic. The code that
follows already handles the case where there _is_ no new object (i.e. the
"old" object is being deleted) as long as we're able to pass through this
type-checking logic.
The new "JSON list of objects - removing item" test covers this problem
by rendering a diff for an object being removed from the end of a list
of objects within a JSON value.
Our initial prototype of new-style diff rendering excluded this because
the old SDK has no support for this construct. However, we want to be able
to introduce this construct in the new SDK without breaking compatibility
with existing versions of Terraform Core, so we need to implement it now
so it's ready to be used once the SDK implements it.
The key associated with each block allows us to properly correlate the
items to recognize the difference between an in-place update of an
existing block and the addition/deletion of a block.
We use cty a little differently when a nested list block contains a
dynamically-typed attribute: it appears as a tuple value instead of a
list value so that we can retain the individual types of each element.
Here we introduce a test for that case, but doing so required also making
the runTestCases function handle types in a stricter way so that it will
produce planned values that match how Terraform Core would do it,
including the necessary late-bound type information for the
dynamically-typed attribute.
Alisdair McDiarmid