84 lines
3.8 KiB
Plaintext
84 lines
3.8 KiB
Plaintext
---
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page_title: 'Import: Usage'
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description: The `terraform import` command is used to import existing infrastructure.
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---
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# Import Usage
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> **Hands-on:** Try the [Import Terraform Configuration](https://learn.hashicorp.com/tutorials/terraform/state-import?in=terraform/state&utm_source=WEBSITE&utm_medium=WEB_IO&utm_offer=ARTICLE_PAGE&utm_content=DOCS) tutorial on HashiCorp Learn.
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The `terraform import` command is used to import existing infrastructure.
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The command currently can only import one resource at a time. This means
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you can't yet point Terraform import to an entire collection of resources
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such as an AWS VPC and import all of it. This workflow will be improved in a
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future version of Terraform.
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~> Warning: Terraform expects that each remote object it is managing will be
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bound to only one resource address, which is normally guaranteed by Terraform
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itself having created all objects. If you import existing objects into Terraform,
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be careful to import each remote object to only one Terraform resource address.
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If you import the same object multiple times, Terraform may exhibit unwanted
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behavior. For more information on this assumption, see
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[the State section](/language/state).
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To import a resource, first write a resource block for it in your
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configuration, establishing the name by which it will be known to Terraform:
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```
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resource "aws_instance" "example" {
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# ...instance configuration...
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}
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```
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The name "example" here is local to the module where it is declared and is
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chosen by the configuration author. This is distinct from any ID issued by
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the remote system, which may change over time while the resource name
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remains constant.
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If desired, you can leave the body of the resource block blank for now and
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return to fill it in once the instance is imported.
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Now `terraform import` can be run to attach an existing instance to this
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resource configuration:
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```shell
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$ terraform import aws_instance.example i-abcd1234
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```
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This command locates the AWS EC2 instance with ID `i-abcd1234`. Then it attaches
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the existing settings of the instance, as described by the EC2 API, to the
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name `aws_instance.example` of a module. In this example the module path
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implies that the root module is used. Finally, the mapping is saved in the
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Terraform state.
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It is also possible to import to resources in child modules, using their paths,
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and to single instances of a resource with `count` or `for_each` set. See
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[_Resource Addressing_](/cli/state/resource-addressing) for more
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details on how to specify a target resource.
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The syntax of the given ID is dependent on the resource type being imported.
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For example, AWS instances use an opaque ID issued by the EC2 API, but
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AWS Route53 Zones use the domain name itself. Consult the documentation for
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each importable resource for details on what form of ID is required.
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As a result of the above command, the resource is recorded in the state file.
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You can now run `terraform plan` to see how the configuration compares to
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the imported resource, and make any adjustments to the configuration to
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align with the current (or desired) state of the imported object.
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## Complex Imports
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The above import is considered a "simple import": one resource is imported
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into the state file. An import may also result in a "complex import" where
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multiple resources are imported. For example, an AWS network ACL imports
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an `aws_network_acl` but also one `aws_network_acl_rule` for each rule.
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In this scenario, the secondary resources will not already exist in
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configuration, so it is necessary to consult the import output and create
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a `resource` block in configuration for each secondary resource. If this is
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not done, Terraform will plan to destroy the imported objects on the next run.
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If you want to rename or otherwise move the imported resources, the
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[state management commands](/cli/commands/state) can be used.
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