terraform/website/docs/configuration/terraform.html.md

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---
layout: "docs"
page_title: "Configuring Terraform"
sidebar_current: "docs-config-terraform"
description: |-
The `terraform` configuration section is used to configure Terraform itself, such as requiring a minimum Terraform version to execute a configuration.
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---
# Terraform Configuration
The `terraform` configuration section is used to configure Terraform itself,
such as requiring a minimum Terraform version to execute a configuration.
This page assumes you're familiar with the
[configuration syntax](/docs/configuration/syntax.html)
already.
## Example
Terraform configuration looks like the following:
```hcl
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terraform {
required_version = "> 0.7.0"
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}
```
## Description
The `terraform` block configures the behavior of Terraform itself.
The currently only allowed configurations within this block are
`required_version` and `backend`.
`required_version` specifies a set of version constraints
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that must be met to perform operations on this configuration. If the
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running Terraform version doesn't meet these constraints, an error
is shown. See the section below dedicated to this option.
See [backends](/docs/backends/index.html) for more detail on the `backend`
configuration.
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**No value within the `terraform` block can use interpolations.** The
`terraform` block is loaded very early in the execution of Terraform
and interpolations are not yet available.
## Specifying a Required Terraform Version
The `required_version` setting can be used to require a specific version
of Terraform. If the running version of Terraform doesn't match the
constraints specified, Terraform will show an error and exit.
When [modules](/docs/configuration/modules.html) are used, all Terraform
version requirements specified by the complete module tree must be
satisified. This means that the `required_version` setting can be used
by a module to require that all consumers of a module also use a specific
version.
The value of this configuration is a comma-separated list of constraints.
A constraint is an operator followed by a version, such as `> 0.7.0`.
Constraints support the following operations:
- `=` (or no operator): exact version equality
- `!=`: version not equal
- `>`, `>=`, `<`, `<=`: version comparison, where "greater than" is a larger
version number
- `~>`: pessimistic constraint operator. Example: for `~> 0.9`, this means
`>= 0.9, < 1.0`. Example: for `~> 0.8.4`, this means `>= 0.8.4, < 0.9`
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For modules, a minimum version is recommended, such as `> 0.8.0`. This
minimum version ensures that a module operates as expected, but gives
the consumer flexibility to use newer versions.
## Syntax
The full syntax is:
```text
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terraform {
required_version = VALUE
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}
```