55 lines
1.6 KiB
Markdown
55 lines
1.6 KiB
Markdown
---
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layout: "docs"
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page_title: "Overrides"
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sidebar_current: "docs-config-override"
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description: |-
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Terraform loads all configuration files within a directory and appends them together. Terraform also has a concept of overrides, a way to create files that are loaded last and merged into your configuration, rather than appended.
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---
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# Overrides
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Terraform loads all configuration files within a directory and
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appends them together. Terraform also has a concept of _overrides_,
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a way to create files that are loaded last and _merged_ into your
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configuration, rather than appended.
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Overrides have a few use cases:
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* Machines (tools) can create overrides to modify Terraform
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behavior without having to edit the Terraform configuration
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tailored to human readability.
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* Temporary modifications can be made to Terraform configurations
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without having to modify the configuration itself.
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Overrides names must be `override` or end in `_override`, excluding
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the extension. Examples of valid override files are `override.tf`,
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`override.tf.json`, `temp_override.tf`.
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Override files are loaded last in alphabetical order.
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Override files can be in Terraform syntax or JSON, just like non-override
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Terraform configurations.
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## Example
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If you have a Terraform configuration `example.tf` with the contents:
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```
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resource "aws_instance" "web" {
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ami = "ami-408c7f28"
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}
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```
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And you created a file `override.tf` with the contents:
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```
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resource "aws_instance" "web" {
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ami = "foo"
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}
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```
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Then the AMI for the one resource will be replaced with "foo". Note
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that the override syntax can be Terraform syntax or JSON. You can
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mix and match syntaxes without issue.
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