- Make these descriptions more similar, since they do basically the same thing.
- Add some subheaders to break up the wall of text and make it more skimmable.
- Nudge people more firmly toward `for_each` if they need to actually
incorporate data from a variable into their instances.
- Add version note so you know whether you can use this yet.
These existing upstream cty functions allow matching strings against
regular expression patterns, which can be useful if you need to consume
a non-standard string format that Terraform doesn't (and can't) have a
built-in function for.
We added the csvdecode function originally with the intent of it being
used with for_each, but because csvdecode was released first we had a
section in its documentation warning about the downsides of using it with
"count", since that seemed like something people would be likely to try.
With resource "for_each" now merged, we can replace that scary section
with a more positive example of using these two features together.
We still include a paragraph noting that "count" _could_ be used here, but
with a caution against doing so. This is in the hope of helping users
understand the difference between these two patterns and why for_each is
the superior choice for most situations.
The search "terraform leading zero" does not find the `format()`
function, which is perfectly capable of adding leading zeros.
Thus I have added this one word to help people find `format()`.
This also includes a previously-missing test that verifies the behavior
described here, implemented as a planning context test for consistency
with how the other ignore_changes tests are handled.
There have been a few questions about this so far which indicated that the
previous docs for this feature were very lacking. This is an attempt to
describe more completely what "any" means, and in particular that it isn't
actually a type at all but rather a placeholder for a type to be selected
dynamically.
Based on some common questions and feedback since the v0.12.0 release,
here we add some small additional content to the documentation for
"dynamic" blocks, covering how to access the keys of the collection being
iterated over and how to fold multiple collections into a single one to
achieve the effect of a nested iteration.
These follow the same principle as jsondecode and jsonencode, but use
YAML instead of JSON.
YAML has a much more complex information model than JSON, so we can only
support a subset of it during decoding, but hopefully the subset supported
here is a useful one.
Because there are many different ways to _generate_ YAML, the yamlencode
function is forced to make some decisions, and those decisions are likely
to affect compatibility with other real-world YAML parsers. Although the
format here is intended to be generic and compatible, we may find that
there are problems with it that'll we'll want to adjust for in a future
release, so yamlencode is therefore marked as experimental for now until
the underlying library is ready to commit to ongoing byte-for-byte
compatibility in serialization.
The main use-case here is met by yamldecode, which will allow reading in
files written in YAML format by humans for use in Terraform modules, in
situations where a higher-level input format than direct Terraform
language declarations is helpful.
This is similar to the function of the same name in Python, generating a
sequence of numbers as a list that can then be used in other
sequence-oriented operations.
The primary use-case for it is to turn a count expressed as a number into
a list of that length, which can then be iterated over or passed to a
collection function to produce that number of something else, as shown
in the example at the end of its documentation page.
- Note that we intentionally omitted it from the sidebar, to reduce confusion.
- Write a summary up top so you can stop reading sooner if you don't actually need this.
* lang/funcs: testing of functions through the lang package API
The function-specific unit tests do not cover the HCL conversion that happens when the functions are called in a terraform configuration. For e.g., HCL converts sets to lists before passing it to the function. This means that we could not test passing a set in the function _unit_ tests.
This adds a higher-level acceptance test, plus a check that every (pure) function has a test.
* website/docs: update function documentation
There was some leftover v0.11-style interpolation syntax here.
We prefer to use a "naked" expression in situations like this where the result
isn't a string, because interpolations returning non-strings is a common source
of confusion for new users.
* funcs/coalesce: return the first non-null, non-empty element from a
sequence.
The go-cty coalesce function, which was originally used here, returns the
first non-null element from a sequence. Terraform 0.11's coalesce,
however, returns the first non-empty string from a list of strings.
This new coalesce function aims to preserve terraform's documented
functionality while adding support for additional argument types. The
tests include those in go-cty and adapted tests from the 0.11 version of
coalesce.
* website/docs: update coalesce function document
The re-introduction of some of the ambiguity between argument and nested
block syntax (for compatibility with existing provider patterns)
unfortunately leads to some interesting consequences for attributes using
this mode.
While the behavior is generally as before in straightforward cases, this
page aims to spell out some of the different usage patterns explicitly
for the benefit of those writing more complex configurations, such as
generic re-usable modules where using argument vs. block syntax leads to
some real differences.
This page is intentionally not linked from anywhere in the part of the
website maintained in the Terraform repository. Instead, it can be linked
from the provider documentation for any argument where this pattern is
used, to help users understand the ways in which that argument might
deviate from the usual behaviors of arguments vs. nested blocks.
Some users are not accustomed to thinking of IP addresses in a bitwise
fashion, so the hope here is to give enough of an introduction to that way
of thinking for the reader to understand what the "newbits" and "netnum"
arguments represent.
For 0.11 I just specified the naming rules; for 0.12, I added some info about
referencing values and tightened up the layout of the optional arguments.
This commit also syncs up descriptions of `depends_on`.
As part of this, I'm copying the entire text of the 0.12
docs/configuration/modules.html page into docs/configuration-0-11/modules.html —
some of the 0.11 pages needed to be able to link to the moved content, I
didn't want to jump versions jarringly, and a close reading didn't reveal
anything in there that's inaccurate for 0.11.
Nick Fagerlund