055c432f12
Our existing functionality for dealing with references generally only has to concern itself with one level of references at a time, and only within one module, because we use it to draw a dependency graph which then ends up reflecting the broader context. However, there are some situations where it's handy to be able to ask questions about the indirect contributions to a particular expression in the configuration, particularly for additional hints in the user interface where we're just providing some extra context rather than changing behavior. This new "globalref" package therefore aims to be the home for algorithms for use-cases like this. It introduces its own special "Reference" type that wraps addrs.Reference to annotate it also with the usually-implied context about where the references would be evaluated. With that building block we can therefore ask questions whose answers might involve discussing references in multiple packages at once, such as "which resources directly or indirectly contribute to this expression?", including indirect hops through input variables or output values which would therefore change the evaluation context. The current implementations of this are around mapping references onto the static configuration expressions that they refer to, which is a pretty broad and conservative approach that unfortunately therefore loses accuracy when confronted with complex expressions that might take dynamic actions on the contents of an object. My hunch is that this'll be good enough to get some initial small use-cases solved, though there's plenty room for improvement in accuracy. It's somewhat ironic that this sort of "what is this value built from?" question is the use-case I had in mind when I designed the "marks" feature in cty, yet we've ended up putting it to an unexpected but still valid use in Terraform for sensitivity analysis and our currently handling of that isn't really tight enough to permit other concurrent uses of marks for other use-cases. I expect we can address that later and so maybe we'll try for a more accurate version of these analyses at a later date, but my hunch is that this'll be good enough for us to still get some good use out of it in the near future, particular related to helping understand where unknown values came from and in tailoring our refresh results in plan output to deemphasize detected changes that couldn't possibly have contributed to the proposed plan. |
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internal | ||
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tools | ||
version | ||
website | ||
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BUGPROCESS.md | ||
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CODEOWNERS | ||
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README.md | ||
checkpoint.go | ||
codecov.yml | ||
commands.go | ||
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help.go | ||
main.go | ||
main_test.go | ||
plugins.go | ||
provider_source.go | ||
signal_unix.go | ||
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working_dir.go |
README.md
Terraform
- Website: https://www.terraform.io
- Forums: HashiCorp Discuss
- Documentation: https://www.terraform.io/docs/
- Tutorials: HashiCorp's Learn Platform
- Certification Exam: HashiCorp Certified: Terraform Associate
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:
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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.
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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.
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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.
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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.