This commit is a wide-ranging set of edits to the pages under
/docs/configuration. Among other things, it
- Separates style conventions out into their own page.
- Separates type constraints and conversion info into their own page.
- Conflates similar complex types a little more freely, since the distinction is
only relevant when restricting inputs for a reusable module or resource.
- Clarifies several concepts that confused me during edits.
In prior versions of Terraform we permitted inconsistent use of indexes
in resource references, but in as of 0.12 the index usage must correlate
properly with whether "count" is set on the resource.
Since users are likely to have existing configurations with incorrect
usage, here we introduce some specialized error messages for situations
where we can detect such issues statically. This seems to cover all of the
common patterns we've seen in practice.
Some usage patterns will fall back on a less-helpful dynamic error here,
but no configurations coming from 0.11 can end up that way because 0.11
did not permit forms such as aws_instance.no_count[count.index].bar that
this validation would not be able to "see".
Our configuration upgrade tool also contains a fix for this already, but
it takes a more conservative approach of adding the index [1] rather than
[count.index] because it can't be sure (without human help) if correlation
of indices is what was intended.
This includes a change to accept and ignore a UTF-8 BOM at the start of
any given native syntax configuration.
Although a BOM is redundant in UTF-8, we learned in #18618 that several
software products on Windows will produce a BOM whenever they save as
UTF-8, so accepting it avoids friction when using those tools to author
or generate Terraform configuration files.
This fixes#18618.
The parent commit fixes an issue where this would previously have led to
a crash. These new test cases verify that parsing is now able to complete
without crashing, though the result is still invalid.
Previously we used the native slash type for the host platform, but that
leads to issues if the same configuration is applied on both Windows and
non-Windows systems.
Since Windows supports slashes and backslashes, we can safely return
always slashes here and require that users combine the result with
subsequent path parts using slashes, like:
"${path.module}/foo/bar"
Previously the above would lead to an error on Windows if path.module
contained any backslashes.
This is not really possible to unit test directly right now since we
always run our tests on Unix systems and filepath.ToSlash is a no-op on
Unix. However, this does include some tests for the basic behavior to
verify that it's not regressed as a result of this change.
This will need to be reported in the changelog as a potential breaking
change, since anyone who was using Terraform _exclusively_ on Windows may
have been using expressions like "${path.module}foo\\bar" which they will
now need to update.
This fixes#14986.
Previously we were doing this rather inconsistently: some commands would
do it and others would not. By doing it here we ensure we always apply the
same normalization, regardless of which operation we're running.
This normalization is mostly for cosmetic purposes in error messages, but
it also ends up being used to populate path.module and path.root and so
it's important that we always produce consistent results here so that
we don't produce flappy changes as users work with different commands.
The fact that thus mutates a data structure as a side-effect is not ideal
but this is the best place to ensure it always gets applied without doing
any significant refactoring, since everything after this point happens in
the backend package where the normalizePath method is not available.
We already catch indirect cycles through the normal cycle detector, but
we never create self-edges in the graph so we need to handle a direct
self-reference separately here.
The prior behavior was simply to produce an incorrect result (since the
local value wasn't assigned a new value yet).
This fixes#18503.
* command/show: adding functions to aid refactoring
The planfile -> statefile -> state logic path was getting hard to follow
with blurry human eyes. The getPlan... and getState... functions were
added to help streamline the logic flow. Continued refactoring may follow.
* command/show: use ctx.Config() instead of a config snapshot
As originally written, the jsonconfig marshaller was getting an error
when loading configs that included one or more modules. It's not clear
if that was an error in the function call or in the configloader itself,
but as a simpler solution existed I did not dig too far.
* command/jsonplan: implement jsonplan.Marshal
Split the `config` portion into a discrete package to aid in naming
sanity (so we could have for example jsonconfig.Resource instead of
jsonplan.ConfigResource) and to enable marshaling the config on it's
own.
This includes:
- An additional check in the format stdlib function to fail if there are
too many arguments given, rather than silently ignoring.
- Refinements for the type unification behavior to allow unification of
object/tuple types into weaker map/list types when no other unification
is possible.
- Improvements to the error messages for failed type conversions on
collection and structural types to talk about mismatching element types
where possible, rather than the outer value.
Older versions of terraform could save the backend hash number in a
value larger than an int.
While we could conditionally decode the state into an intermediary data
structure for upgrade, or detect the specific decode error and modify
the json, it seems simpler to just decode into the most flexible value
for now, which is a uint64.
Make sure that NodeDestroyableDataResource has a ResolvedProvider to
call EvalWriteState. This entails setting the ResolvedProvider in
concreteResourceDestroyable, as well as calling EvalGetProvider in
NodeDestroyableDataResource to load the provider schema.
Even though writing the state for a data destroy node should just be
removing the instance, every instance written sets the Provider for the
entire resource. This means that when scaling back a counted data
source, if the removed instances are written last, the data source will
be missing the provider in the state.
Validate should not require state or changes to be present. Break out
early when using evaluationStateData during walkValidate before checking
state or changes, to prevent errors when indexing resources that haven't
been expanded.
Both depends_on and ignore_changes contain references to objects that we
can validate.
Historically Terraform has not validated these, instead just ignoring
references to non-existent objects. Since there is no reason to refer to
something that doesn't exist, we'll now verify this and return errors so
that users get explicit feedback on any typos they may have made, rather
than just wondering why what they added seems to have no effect.
This is particularly important for ignore_changes because users have
historically used strange values here to try to exploit the fact that
Terraform was resolving ignore_changes against a flatmap. This will give
them explicit feedback for any odd constructs that the configuration
upgrade tool doesn't know how to detect and fix.
Nick Fagerlund