The set of paths which caused a resource update to require replacement
has been stored in the plan since 0.15.0 (#28201). This commit adds a
simple JSON representation of these paths, allowing consumers of this
format to determine exactly which paths caused the resource to be
replaced.
This representation is intentionally more loosely encoded than the JSON
state serialization of paths used for sensitive attributes. Instead of a
path step being represented by an object with type and value, we use a
more-JavaScripty heterogenous array of numbers and strings. Any
practical consumer of this format will likely traverse an object tree
using the index operator, which should work more easily with this
format. It also allows easy prefix comparison for consumers which are
tracking paths.
While updating the documentation to include this new field, I noticed
that some others were missing, so added them too.
When rendering the JSON plan sensitivity output, if the plan contained
unknown collection or structural types, Terraform would crash. We need
to detect unknown values before attempting to iterate them.
Unknown collection or structural values cannot have sensitive contents
accidentally displayed, as those values are not known until after apply.
As a result we return an empty value of the appropriate type for the
sensitivity mapping.
Similar to `after_unknown`, `before_sensitive` and `after_sensitive` are
values with similar structure to `before` and `after` which encode the
presence of sensitive values in a planned change. These should be used
to obscure sensitive values from human-readable output.
These values follow the same structure as the `before` and `after`
values, replacing sensitive values with `true`, and non-sensitive values
with `false`. Following the `after_unknown` precedent, we omit
non-sensitive `false` values for object attributes/map values, to make
serialization more compact.
One difference from `after_unknown` is that a sensitive complex value
(collection or structural type) is replaced with `true`. If the complex
value itself is sensitive, all of its contents should be obscured.
The omitUnknowns and unknownAsBool functions were previously trying hard
to preserve the same collection types in the output as they had in the
input, by attempting to keep everything matched up so that the results
would be valid.
Unfortunately, this turns out to be a harder problem than we originally
thought: it was possible for a collection value going in to produce
inconsistent element types out (and thus a panic) in the following
situations:
- when a collection with mixed known and unknown values was passed in
to omitUnknowns.
- when a collection of collections where the inner collections are a
mixture of empty and not empty in unknownAsNull.
The results of these functions are only used to marshal to JSON anyway,
and JSON serialization can't distinguish between the three sequence types
or the two mapping types, so in practice we can just standardize on
converting all sequences to tuple and all mappings to object here and not
change the resulting output at all, and then we don't have to worry about
making sure all of the inner types get preserved exactly.
A nice consequence of that relaxation is that we can now do what we
originally wanted to do with unknownAsBool, and omit map keys and
object attributes altogether if their values would've been false,
producing a much more compact result. This is easiest to do now when
there's only one known user of this JSON plan output, and we know that
user will treat both false and omitted as the same here.
* command/show: properly marshal attribute values to json
marshalAttributeValues in jsonstate and jsonplan packages was returning
a cty.Value, which json/encoding could not marshal. These functions now
convert those cty.Values into json.RawMessages.
* command/jsonplan: planned values should include resources that are not changing
* command/jsonplan: return a filtered list of proposed 'after' attributes
Previously, proposed 'after' attributes were not being shown if the
attributes were not WhollyKnown. jsonplan now iterates through all the
`after` attributes, omitting those which are not wholly known.
The same was roughly true for after_unknown, and that structure is now
correctly populated. In the future we may choose to filter the
after_unknown structure to _only_ display unknown attributes, instead of
all attributes.
* command/jsonconfig: use a unique key for providers so that aliased
providers don't get munged together
This now uses the same "provider" key from configs.Module, e.g.
`providername.provideralias`.
* command/jsonplan: unknownAsBool needs to iterate through objects that are not wholly known
* command/jsonplan: properly display actions as strings according to the RFC,
instead of a plans.Action string.
For example:
a plans.Action string DeleteThenCreate should be displayed as ["delete",
"create"]
Tests have been updated to reflect this.
* command/jsonplan: return "null" for unknown list items.
The length of a list could be meaningful on its own, so we will turn
unknowns into "null". The same is less likely true for maps and objects,
so we will continue to omit unknown values from those.
Alisdair McDiarmid