A very common question since we launched the two repetition constructs
is how to deal with situations where the input data structure doesn't
match one-to-one with the desired configuration.
This adds some full worked examples of two common situations that have
come up in questions. To avoid adding a lot of extra content to the
already-large "expressions" and "resources" pages, the main bulk of this
new content lives with the relevant functions themselves as a full example
of one thing they are good for, and then we'll link to them from the two
general documentation sections where folks are likely to be reading when
they encounter the problem.
* upstream/master: (66 commits)
lang/eval: more evalContext fixups
Update CHANGELOG.md
Cleanup after v0.12.10 release
v0.12.10
website / help: reconcile 'validate' command docs
website: Document behavior of `self` object for provisioners
vendor: switch to HCL 2.0 in the HCL repository
Update communicator/ssh/communicator.go
copy client pointer for keep-alive loop
Update CHANGELOG.md
slow down tfce polling to 1s
typos. some code, some text.
Remove -check-variables flag from the docs
Merge cleanup, remove `license` parameter in favor of bool `accept_license`, adjust how license acceptance is done, update hab provisioner doc.
vendor latest go-tfe
clean up go mod for go-tfe
tfce test additions
update to go-tfe 0.3.23
cost estimation status polling
go-tfe dep update to 0.3.22
...
Previously we were using the experimental HCL 2 repository, but now we'll
shift over to the v2 import path within the main HCL repository as part of
actually releasing HCL 2.0 as stable.
This is a mechanical search/replace to the new import paths. It also
switches to the v2.0.0 release of HCL, which includes some new code that
Terraform didn't previously have but should not change any behavior that
matters for Terraform's purposes.
For the moment the experimental HCL2 repository is still an indirect
dependency via terraform-config-inspect, so it remains in our go.sum and
vendor directories for the moment. Because terraform-config-inspect uses
a much smaller subset of the HCL2 functionality, this does still manage
to prune the vendor directory a little. A subsequent release of
terraform-config-inspect should allow us to completely remove that old
repository in a future commit.
The cidrsubnets function signature is intentionally very low-level and
focused on the core requirement of generating addresses. This registry
module then wraps it with some additional functionality to make it more
convenient to generate and use subnet address ranges.
This is a companion to cidrsubnet that allows bulk-allocation of multiple
subnet addresses at once, with automatic numbering.
Unlike cidrsubnet, cidrsubnets allows each of the allocations to have a
different prefix length, and will pack the networks consecutively into the
given address space. cidrsubnets can potentially create more complicated
addressing schemes than cidrsubnet alone can, because it's able to take
into account the full set of requested prefix lengths rather than just
one at a time.
* command/import: properly use `-provider` supplied on the command line
The import command now attaches the provider configuration in the resource
instance, if set. That config is attached to the NodeAbstractResource
during the import graph building. This prevents errors when the implied
provider is not actually in the configuration at all, which may happen
when a configuration is using the `-beta` version of a provider (and
only that `-beta` version).
* command/import: fix variable reassignment and update docs
Fixes#22564
For a long time now we've been advising against the use of provisioners,
but our documentation for them is pretty prominent on the website in
comparision to the better alternatives, and so it's little surprise that
many users end up making significant use of them.
Although in the longer term a change to our information architecture would
probably address this even better, this is an attempt to be explicit about
the downsides of using provisioners and to prominently describe the
alternatives that are available for common use-cases, along with some
reasons why we consider them to be better.
I took the unusual step here of directly linking to specific provider
documentation pages about the alternatives, even though we normally try
to keep the core documentation provider-agnostic, because otherwise that
information tends to be rather buried in the provider documentation and
thus the reader would be reasonable to use provisioners just because we're
not giving specific enough alternative recommendations.
* website/formatdate: update example
The given example was showing HOUR:MONTH instead of HOUR:MINUTE
Fixes#22598
* website/import: remove reference to no-longer-working option
Users can no longer supply `-config=""` to tell Terraform not to load
configuration for import.
Fixes#22294
* website/provisioners: `host` is required in connection blocks
Fixes#21877
* website/variables: clarify variable definition precedence
It was not entirely obvious that a variable could not be assigned
multiples times in a single source.
Fixes#21682
* website/backend/local: add `workspace_dir` attribute
Fixes#21391
* website/output: `sensitive` outputs are redacted in output
Fixes#21502
* website/backends: sidebar order tweak
It makes sense for backend 'configuration' to appear before 'init'.
Fixes#13796
* Revert "website/formatdate: update example"
This reverts commit ccd93c86ddd15a21625c0767702ee1cc62e77254.
Reference: https://github.com/hashicorp/terraform/issues/16697
Enumerates a set of regular file names from a given glob pattern. Implemented via the Go stdlib `path/filepath.Glob()` functionality. Notably, stdlib does not support `**` or `{}` extended patterns. See also: https://github.com/golang/go/issues/11862
To support the extended glob patterns, it will require adding a dependency on a third party library or adding our own matching code.
The Terraform Enterprise brand has now been split into two parts:
- Terraform Cloud is the application that helps teams use Terraform together,
with remote state storage, a shared run environment, etc.
- Terraform Enterprise is the on-premise distribution that lets enterprises run
a private instance of the Terraform Cloud application.
The former TFE docs have been split accordingly.
- 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.
Ran into an issue requiring `-var='foo=bar'` over `-var 'foo=bar'`.
Without the `=` the generic response came back:
```
Usage: terraform plan [options] [DIR]
Generates an execution plan for Terraform.
This execution plan can be reviewed...
```
Terraform `0.12.2`
Team tokens never worked with the `atlas` backend, but the `remote` backend
uses them as intended; they can perform plans and applies on workspaces where
the associated team has at least plan or write permissions, respectively.
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()`.
The correct environment variable corresponding to the `ca_file` variable is `CONSUL_CACERT` and not `CONSUL_CAFILE`.
See `backend/remote-state/consul/backend.go` line 77.
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.
* Correct fmt -check
With `-check=false` the exit status is always zero.
With `-check=true` the exit status is zero when all files are properly formatted and non-zero otherwise.
* update fmt documentation to use short form for -diff and -check
We previously had some notes about handling configuration variants just
tacked on to the "dependency inversion" section as an afterthought, but
this idea is a major use-case for dependency inversion so it deserves its
own section and a specific example.
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.
Using az login and then terraform init from the command line I got `Error: Either an Access Key / SAS Token or the Resource Group for the Storage Account must be specified`
We've seen in the past that some users try to use this form with the
ssh:// URL prefix, so we'll mention explicitly that this is invalid and
show a working example of how to use it without the URL scheme prefix.
- 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.
The definition of split was referring the built-in function join. However, join is just one of the ways a string might have been created, and this could cause confusion.
In the terraform state documentation the verb "map" is widely used to
describe the relationship between an item in the state and in the real world
whereas the verb "attach" is not used anywhere.
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`.
'legacy' doesn't seem to be a thing anymore, and we were missing some
of the other values for -type. Also -no-color doesn't seem to be
relevant to this command.
1. The double "$" in the template confuses readers
2. As far as I can tell the variable "count" is not used either in this example
(it is in the next example though)
* docs: elaborate on supported remote backend versions
This PR adds a few lines to the docs to indicate which commands are
supported by what version of the remote backend and it makes a
recommendation about which version to use.
* Clarify remote state storage w/ TFE [skip ci]
Specifically, that this is the backend to use with remote state (all
tiers) and Free-Tier vs. Enterprise tiers differ in remote operations
* website: Arrange remote backend info differently
We have released the v0.12-oriented content to the website early in order
to support the beta process, but in some places we neglected to explicitly
mark features or content as being v0.12-only.
Here we add explicit markers to the main cases we've seen where readers
have reported confusion, along with some other tweaks in similar vein.
Terraform is way bigger than the core CLI tools and the language
now, and the docs have grown accordingly. So we're adding a
global index page to help users get around the many sections of the
docs site, and bumping the CLI/core docs down so they're no longer at the
top of the hierarchy.
The "right" (as in, conceptually pure) way to do this would be to actually
create a new level of directory hierarchy in between. But that would be real
expensive and annoying — the amount of 301s and links to edit would be
monumental, and it wouldn't gain us much beyond a certain picture-straightening
satisfaction, so I'm resisting the temptation.
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.
The "terraform fmt" command produces a different canonical form than we
were showing in our examples here. Our examples should always reflect the
conventions applied by "terraform fmt" to avoid confusion.
(This particular decision is a pragmatic one because the formatter design
needs to use the same rules for the colon in the ? : conditional operator
as for the colon in "for" expressions.)
Since references to attributes of resources are by far the most common
reference type, and the mapping of resource type config to the attributes
is not always obvious, here we give some real examples of patterns for
accessing different configuration constructs within resource blocks along
with the resource type's exported attributes.
Since we don't have any real examples of labelled nested blocks yet (the
current SDK doesn't support them) I've included a hypothetical example for
now just to establish the patterns around them in preparation for
beginning to introduce them as we roll out this feature in the SDK.
As well as some general consolidation and reorganizing, this also includes
some updated advice for making the best use of new Terraform v0.12
features to create infrastructure building-blocks.
In particular, the "Module Usage" documentation is now consolidated into
the configuration section in order to bring all of our general language
documentation together, and the top-level "Modules" section is now
primarily focused on module _authors_ as an audience, covering topics such
as publishing modules and designing them for reuse.
* docs: update plan command documentation. Fixes#19235
* docs: added a missing reserved variable name. Fixes#19159.
* website: add note that resource names cannot start with a number
* website: add some notes to the 0.12 upgrade guide
The go-getter library that is used by the module loader validates S3 URLs in the parseURL function. That function assumes path-style URLs and fails on virtual-hosted-style URLs.
In 0.12, the outputs for a data source of terraform_remote_state are
nested under the 'outputs' attribute [1]. This updates the docs
to make this change clearer.
Worked with @radeksimko at Terraform hackday, who has submitted a
related upgrade guide [2]
[1] 1f4d2f4c50/builtin/providers/terraform/data_source_state.go (L16-L43)
[2] d8e00191b7
Because of the different possibilities for arranging the nav sidebars, we want
to make sure:
- IDs for the 0.11 and 0.12 language docs have a common prefix.
- That prefix is not the exact string `docs-config`.
Have I mentioned before that I really dislike this prefix matching behavior.
This is a non-working commit, because a bunch of links (including the sidebar
nav) are broken. Using a transition commit like this makes it easier to see the
changes necessary to get this content woven into the site.
In prior versions, we recommended using hash functions in conjunction with
the file function as an idiom for detecting changes to upstream blobs
without fetching and comparing the whole blob.
That approach relied on us being able to return raw binary data from
file(...). Since Terraform strings pass through intermediate
representations that are not binary-safe (e.g. the JSON state), there was
a risk of string corruption in prior versions which we have avoided for
0.12 by requiring that file(...) be used only with UTF-8 text files.
The specific case of returning a string and immediately passing it into
another function was not actually subject to that corruption risk, since
the HIL interpreter would just pass the string through verbatim, but this
is still now forbidden as a result of the stricter handling of file(...).
To avoid breaking these use-cases, here we introduce variants of the hash
functions a with "file" prefix that take a filename for a disk file to
hash rather than hashing the given string directly. The configuration
upgrade tool also now includes a rule to detect the documented idiom and
rewrite it into a single function call for one of these new functions.
This does cause a bit of function sprawl, but that seems preferable to
introducing more complex rules for when file(...) can and cannot read
binary files, making the behavior of these various functions easier to
understand in isolation.
It's not normally necessary to make explicit type conversions in Terraform
because the language implicitly converts as necessary, but explicit
conversions are useful in a few specialized cases:
- When defining output values for a reusable module, it may be desirable
to force a "cleaner" output type than would naturally arise from a
computation, such as forcing a string containing digits into a number.
- Our 0.12upgrade mechanism will use some of these to replace use of the
undocumented, hidden type conversion functions in HIL, and force
particular type interpretations in some tricky cases.
- We've found that type conversion functions can be useful as _temporary_
workarounds for bugs in Terraform and in providers where implicit type
conversion isn't working correctly or a type constraint isn't specified
precisely enough for the automatic conversion behavior.
These all follow the same convention of being named "to" followed by a
short type name. Since we've had a long-standing convention of running all
the words together in lowercase in function names, we stick to that here
even though some of these names are quite strange, because these should
be rarely-used functions anyway.
The sethaselement, setintersection, and setunion functions are defined in
the cty stdlib. Making them available in Terraform will make it easier to
work with sets, and complement the currently-Terraform-specific setproduct
function.
In the long run setproduct should probably move into the cty stdlib too,
but since it was submitted as a Terraform function originally we'll leave
it here now for simplicity's sake and reorganize later.
In our new world it produces either a set of a tuple type or a list of a
tuple type, depending on the given argument types.
The resulting collection's element tuple type is decided by the element
types of the given collections, allowing type information to propagate
even if unknown values are present.
This document was previously copied to the "Extending Terraform" section (in the
terraform-website repo), and the old URL was redirected so that the copy in
/guides can no longer be reached on the website. But the old copy of the file
remained, and now it runs the risk of confusing contributors, since the copy in
terraform-website/.../docs/extend is the more up-to-date version.
The AWS Go SDK automatically provides a default request retryer with exponential backoff that is invoked via setting `MaxRetries` or leaving it `nil` will default to 3. The terraform-aws-provider `config.Client()` sets `MaxRetries` to 0 unless explicitly configured above 0. Previously, we were not overriding this behavior by setting the configuration and therefore not invoking the default request retryer.
The default retryer already handles HTTP error codes above 500, including S3's InternalError response, so the extraneous handling can be removed. This will also start automatically retrying many additional cases, such as temporary networking issues or other retryable AWS service responses.
Changes:
* s3/backend: Add `max_retries` argument
* s3/backend: Enhance S3 NoSuchBucket error to include additional information
We missed this one on a previous pass of bringing in most of the cty
stdlib functions.
This will resolve#17625 by allowing conversion from Terraform's
conventional RFC 3339 timestamps into various other formats.
This function is similar to the template_file data source offered by the
template provider, but having it built in to the language makes it more
convenient to use, allowing templates to be rendered from files anywhere
an inline template would normally be allowed:
user_data = templatefile("${path.module}/userdata.tmpl", {
hostname = format("petserver%02d", count.index)
})
Unlike the template_file data source, this function allows values of any
type in its variables map, passing them through verbatim to the template.
Its tighter integration with Terraform also allows it to return better
error messages with source location information from the template itself.
The template_file data source was originally created to work around the
fact that HIL didn't have any support for map values at the time, and
even once map support was added it wasn't very usable. With HCL2
expressions, there's little reason left to use a data source to render
a template; the only remaining reason left to use template_file is to
render a template that is constructed dynamically during the Terraform
run, which is a very rare need.
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.
* Upgrading to 2.0.0 of github.com/hashicorp/go-azure-helpers
* Support for authenticating using Azure CLI
* backend/azurerm: support for authenticating using the Azure CLI
This change enables a few related use cases:
* AWS has partitions outside Commercial, GovCloud (US), and China, which are the only endpoints automatically handled by the AWS Go SDK. DynamoDB locking and credential verification can not currently be enabled in those regions.
* Allows usage of any DynamoDB-compatible API for state locking
* Allows usage of any IAM/STS-compatible API for credential verification
* backend/azurerm: removing the `arm_` prefix from keys
* removing the deprecated fields test because the deprecation makes it fail
* authentication: support for custom resource manager endpoints
* Adding debug prefixes to the log statements
* adding acceptance tests for msi auth
* including the resource group name in the tests
* backend/azurerm: support for authenticating using a SAS Token
* resolving merge conflicts
* moving the defer to prior to the error
* backend/azurerm: support for authenticating via msi
* adding acceptance tests for msi auth
* including the resource group name in the tests
* support for using the test client via msi
* vendor updates
- updating to v21.3.0 of github.com/Azure/azure-sdk-for-go
- updating to v10.15.4 of github.com/Azure/go-autorest
- vendoring github.com/hashicorp/go-azure-helpers @ 0.1.1
* backend/azurerm: refactoring to use the new auth package
- refactoring the backend to use a shared client via the new auth package
- adding tests covering both Service Principal and Access Key auth
- support for authenticating using a proxy
- rewriting the backend documentation to include examples of both authentication types
* switching to use the build-in logging function
* documenting it's also possible to retrieve the access key from an env var
...and one other reference to the application data directory.
Context:
https://docs.microsoft.com/en-us/windows/desktop/shell/knownfolderid#folderid_roamingappdata
In newer Windows versions, the folder accessible as `%APPDATA%` (and via various
APIs) is actually at something like "documents and settings\user\application
data\roaming", while earlier versions omit the "\roaming" part of the path. This
means you can confuse people by referring to the "application data" directory by
its human name, because "roaming" is the real application data directory, but it
looks like a subdirectory of "application data".
Thus, it's less confusing to just use the `%APPDATA%` variable, with the added
benefit that you can copy and paste the path and it'll just work in most places.
If the user uses the auto-expire value in the backend/swift settings
then swift will automatically delete their Statefile which is likely
something the user doesn't want given how Terraform works.
Since the index page is long, by the time the reader reaches the end of
it the relevant portion if the navigation is unlikely to be visible. To
compensate for this, we'll link to the first sub-section and thus give
the user an opportunity to notice the navigation structure for the rest
of the pages.
This has been replaced with an "Expressions" page.
Also includes a number of changes to Markdown style to conform to our
usual conventions, applied automatically by my editor while making these
changes.
This has now been superseded by the expressions.html.md file in the same
directory. As part of deploying this, the former URL for this page must
be redirected to the expressions page to retain a target for any
existing links on third-party sites.
This kinda-weird feature was previously quite severely under-documented in
terms of exactly what effect it has. This new documentation for it first
attempts to frame it as something that should be rarely used, and then
explains in more detail exactly how it behaves for different top-level
block types within the configuration.
As part of revamping the "Configuration" portion of the website for the
v0.12 release, here we update the Terraform Settings page to use a similar
"guide-like" writing style as the other updated pages in this section.
Previously we just listed out all of the functions in alphabetical order
inside the "Interpolation Syntax" page, but that format doesn't leave much
room for details and usage examples.
Now we give each function its own page, and categorize them for easier
navigation. While many functions are very simple and don't really warrant
a full page, certain functions do have additional details that are worth
mentioning and this structure scales better for those more complicated
functions.
So far this includes only the numeric and string functions. Other
categories will follow in subsequent commits.
This rewrite of the "Configuration Syntax" page now gives some more detail
on the top-level structural constructs and de-emphasizes the name "HCL"
as subordinate to "the Terraform language".
It also now includes some commentary on valid identifiers and comments,
and issues around character encodings and line endings.
In addition, we now have a new "Expressions" page that replaces the old
"Interpolation Syntax" page, covering the expression language features
we inherit from HCL and how they behave in the context of Terraform.
The "Expressions" page currently links to a page about the built-in
functions which does not yet exist. This will be created in a later
commit.
This adopts a more guide-like writing style, similar to what prior commits
have done to some other subsections of this section.
The data sources page has not got any real attention since the feature
was first added, and our vocabulary for describing them and their
lifecycle hadn't quite settled when the page was originally written. This
new version is consistent in how it uses "data source" to describe the
feature that providers offer and "data resource" to describe what is
created by a "data" block in configuration, which then allows us to
draw on the many shared features between both data and managed resources.
For the moment this waits until "data resource" is defined in order to
first introduce the qualifier "managed resource". We may wish to revise
this again to mention that more specific nomenclature in passing on the
"Resources" page, in case a user encounters it elsewhere and wants to
learn what it means without needing to be familiar with data resources
first.
This adopts a more guide-like writing style, similar to what prior commits
have done to some other subsections of this section.
Since we already have a whole top-level section devoted to modules, there
is no need for full coverage of all of their features here. Instead, this
section focuses on an an initial introduction to what modules are and
the basics of their usage within the Terraform language. We then link
to the main modules section for the full details.
This adopts a more guide-like writing style, similar to what prior commits
have done to some other subsections of this section.
In the process of writing this, I identified some unclear statements in
the "Resources" subsection, and so these are also revised here for
consistency with the output values documentation.
These revisions reflect this sub-section's new earlier placement in the
sub-section list, leading to a more guide-like style for the initial
sections.
Also includes some minor copy-editing to align terminology with that
introduced in the prior commit for the "Resources" docs page.
This is now the leading subsection of the Configuration section of the
docs, and so this rewrite intends to make it more "guide-like" and as
accessible as possible to those who are not yet familiar with other
Terraform concepts.
This rewrite also attempts to introduce some consistency into our
vocabulary, which should eventually be reflected throughout our
documentation. In particular:
- "Resource" refers to the block the user writes in configuration, while
"Resource _Type_" refers to what the provider defines. We previously
used "resource" for both of these interchangeably.
- "Resource" is no longer used to refer to what gets created and managed
in remote APIs as a result of a resource block in configuration. Lacking
a good distinct name for these, this guide uses the word "object",
qualifying it as "infrastructure object" or "remote object" where
necessary to retain clarity. This distinction is important to enable
a clear description of resource lifecycle.
- "Argument" refers to an element (attribute or block) within a resource
block. This terminology was already being used in some places, so we
embrace it here as a way to distinguish from "attribute", which is
what a resource _exports_ for use in expressions.
- Since interpolation is no longer needed to use expressions in the
language, the word "expression" is used to describe the definition of
a value that might involve some computation. Where necessary, this is
used with a modifier "arbitrary expression" to contrast with situations
where the set of allowed expression constructs is constrained.
The prior content on this page was little more than an instruction to
begin navigating the sub-sections of this section.
The new content aims to give a broad overview of some of the language
concepts and a syntax example, in order to create some context to help
the user navigate the subsections more easily.
This also introduces for the first time usage of the term "the Terraform
language". This was previously left un-named, leading to some awkward
sentence constructions elsewhere in the docs. This new name gives us
some specific terminology to use in order to contrast the language that
exists at Terraform's level of abstraction, defining the semantics, from
the underlying grammar provided by HCL.
With the additional configuration language features coming in Terraform
v0.12, our existing documentation structure is beginning to strain.
Here we reorganize the navigation slightly in order to introduce the
concepts in a more appropriate order so that we can reveal complexity
more gradually. Subsequent commits will revise the content of these
pages to better reflect the new sequencing.
The "Environment Variables" page is moved from the Configuration section
into the "Commands" section, since it is not considered a part of the
configuration language and thus more appropriate in the CLI documentation.
The old placement is reflective of the broader purpose that the
"Configuration" section had originally, but its new focus will be on
the Terraform language (.tf files) in particular, with other aspects of
customizing Terraforms behavior covered in other sections.
website: Reconcile docs about plugin discovery and downloading
I'm attempting to keep things simple for normal users while making sure we've
got the full behavior written down somewhere for plugin developers.
This commit doesn't stand alone; it's paired with a commit in the
terraform-website repo, to deal with some related content in the "extend"
section.
cgriggs01