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Martin Atkins 37b1413ab3 core: Handle root and child module input variables consistently
Previously we had a significant discrepancy between these two situations:
we wrote the raw root module variables directly into the EvalContext and
then applied type conversions only at expression evaluation time, while
for child modules we converted and validated the values while visiting
the variable graph node and wrote only the _final_ value into the
EvalContext.

This confusion seems to have been the root cause for #29899, where
validation rules for root module variables were being applied at the wrong
point in the process, prior to type conversion.

To fix that bug and also make similar mistakes less likely in the future,
I've made the root module variable handling more like the child module
variable handling in the following ways:
 - The "raw value" (exactly as given by the user) lives only in the graph
   node representing the variable, which mirrors how the _expression_
   for a child module variable lives in its graph node. This means that
   the flow for the two is the same except that there's no expression
   evaluation step for root module variables, because they arrive as
   constant values from the caller.
 - The set of variable values in the EvalContext is always only "final"
   values, after type conversion is complete. That in turn means we no
   longer need to do "just in time" conversion in
   evaluationStateData.GetInputVariable, and can just return the value
   exactly as stored, which is consistent with how we handle all other
   references between objects.

This diff is noisier than I'd like because of how much it takes to wire
a new argument (the raw variable values) through to the plan graph builder,
but those changes are pretty mechanical and the interesting logic lives
inside the plan graph builder itself, in NodeRootVariable, and
the shared helper functions in eval_variable.go.

While here I also took the opportunity to fix a historical API wart in
EvalContext, where SetModuleCallArguments was built to take a set of
variable values all at once but our current caller always calls with only
one at a time. That is now just SetModuleCallArgument singular, to match
with the new SetRootModuleArgument to deal with root module variables.
2022-01-10 12:26:54 -08:00
.circleci udpate CI go version 2021-10-08 15:53:08 -04:00
.github build: CGO_ENABLED when building for macOS 2022-01-06 14:51:09 -08:00
docs docs: Fix typo in docs/plugin-protocol/releasing-new-version.md 2021-12-27 14:29:02 +09:00
internal core: Handle root and child module input variables consistently 2022-01-10 12:26:54 -08:00
scripts no need for TF_FORK=0 2021-10-28 11:51:39 -04:00
tools build: Add exhaustive switch statement lint 2021-09-24 15:12:44 -04:00
version main: Report version information for "interesting" dependencies 2021-11-05 16:47:38 -07:00
website Merge pull request #30280 from Mukesh05/patch-2 2022-01-07 10:22:57 -05:00
.gitignore Remove several ignore rules 2021-09-01 14:37:26 -05:00
.go-version update to go1.17.2 2021-10-08 15:54:02 -04:00
.tfdev Remove revision from version command 2021-01-12 16:35:30 -05:00
BUGPROCESS.md Update BUGPROCESS.md 2020-12-10 12:15:39 -05:00
CHANGELOG.md Update CHANGELOG.md 2022-01-10 12:24:53 -08:00
CODEOWNERS etcdv3 backend is unmaintained 2021-07-20 13:59:08 -04:00
Dockerfile switch to hashicorp docker mirror 2020-10-29 22:37:11 -04:00
LICENSE Adding license 2014-07-28 13:54:06 -04:00
Makefile update make website workflow 2021-12-16 16:10:17 -08:00
README.md fix broken logo in readme (#29705) 2021-10-05 16:31:02 -04:00
checkpoint.go Move command/ to internal/command/ 2021-05-17 14:09:07 -07:00
codecov.yml update to match new default branch name (#27909) 2021-02-24 13:36:47 -05:00
commands.go command: Remove the experimental "terraform add" command 2021-10-20 06:42:47 -07:00
go.mod getmodules: Use go-getter v1.5.10 and return to upstream GitGetter 2022-01-03 11:44:16 -08:00
go.sum getmodules: Use go-getter v1.5.10 and return to upstream GitGetter 2022-01-03 11:44:16 -08:00
help.go Update links to CLI docs in code comments, messages, and readme 2021-01-22 12:22:21 -08:00
main.go main: Report version information for "interesting" dependencies 2021-11-05 16:47:38 -07:00
main_test.go remove the use of panicwrap 2021-10-28 11:51:39 -04:00
plugins.go Move command/ to internal/command/ 2021-05-17 14:09:07 -07:00
provider_source.go Move command/ to internal/command/ 2021-05-17 14:09:07 -07:00
signal_unix.go Upgrade to Go 1.17 2021-08-17 15:20:05 -07:00
signal_windows.go Upgrade to Go 1.17 2021-08-17 15:20:05 -07:00
version.go Remove revision from version command 2021-01-12 16:35:30 -05:00
working_dir.go workdir: Start of a new package for working directory state management 2021-09-10 14:56:49 -07:00

README.md

Terraform

Terraform

Terraform is a tool for building, changing, and versioning infrastructure safely and efficiently. Terraform can manage existing and popular service providers as well as custom in-house solutions.

The key features of Terraform are:

  • Infrastructure as Code: Infrastructure is described using a high-level configuration syntax. This allows a blueprint of your datacenter to be versioned and treated as you would any other code. Additionally, infrastructure can be shared and re-used.

  • Execution Plans: Terraform has a "planning" step where it generates an execution plan. The execution plan shows what Terraform will do when you call apply. This lets you avoid any surprises when Terraform manipulates infrastructure.

  • Resource Graph: Terraform builds a graph of all your resources, and parallelizes the creation and modification of any non-dependent resources. Because of this, Terraform builds infrastructure as efficiently as possible, and operators get insight into dependencies in their infrastructure.

  • Change Automation: Complex changesets can be applied to your infrastructure with minimal human interaction. With the previously mentioned execution plan and resource graph, you know exactly what Terraform will change and in what order, avoiding many possible human errors.

For more information, see the introduction section of the Terraform website.

Getting Started & Documentation

Documentation is available on the Terraform website:

If you're new to Terraform and want to get started creating infrastructure, please check out our Getting Started guides on HashiCorp's learning platform. There are also additional guides to continue your learning.

Show off your Terraform knowledge by passing a certification exam. Visit the certification page for information about exams and find study materials on HashiCorp's learning platform.

Developing Terraform

This repository contains only Terraform core, which includes the command line interface and the main graph engine. Providers are implemented as plugins, and Terraform can automatically download providers that are published on the Terraform Registry. HashiCorp develops some providers, and others are developed by other organizations. For more information, see Extending Terraform.

To learn more about compiling Terraform and contributing suggested changes, please refer to the contributing guide.

To learn more about how we handle bug reports, please read the bug triage guide.

License

Mozilla Public License v2.0