# learn-terraform-import

**Repository Path**: mirrors_hashicorp/learn-terraform-import

## Basic Information

- **Project Name**: learn-terraform-import
- **Description**: Learn how to import existing configuration into Terraform
- **Primary Language**: Unknown
- **License**: MPL-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-08-08
- **Last Updated**: 2026-05-23

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

## Learn Terraform Import

Learn how to import existing resources under Terraform's management.

Follow along with the [Learn Terraform Import tutorial](https://developer.hashicorp.com/terraform/tutorials/state/state-import).

### Install prerequisites

1. Terraform: https://www.terraform.io/downloads.html
1. Docker: https://docs.docker.com/get-docker/

### Create a docker container

1. Run this docker command to create a container with the latest nginx image.

    ```shell
    docker run --name hashicorp-learn --detach --publish 8080:80 nginx:latest
    ```

1. Verify container is running by running `docker ps` or visiting `0.0.0.0:8080`
    in your web browser.

    ```shell
    docker ps --filter "name=hashicorp-learn"
    ```

### Import container resource

1. Initialize your workspace by running `terraform init`.

1. Add empty resource stub to `docker.tf` for the container.

    ```hcl
    resource "docker_container" "web" { }
    ```

1. Import the container into Terraform state.

    ```shell
    terraform import docker_container.web $(docker inspect -f {{.ID}} hashicorp-learn)
    ```

1. Now the container is in your terraform configuration's state.

    ```shell
    terraform show
    ```

1. Run `terraform plan`. Terraform shows errors for missing required arguments
    (`image`, `name`).

    ```shell
    terraform plan
    ```

1. Generate configuration and save it in `docker.tf`, replacing the empty
    resource created earlier.

    ```shell
    terraform show -no-color > docker.tf
    ```

1. Re-run `terraform plan`.
    ```shell
    terraform plan
    ```

1. Terraform will show warnings and errors about a deprecated attribute
    (`links`), and several read-only attributes (`ip_address`, `network_data`,
    `gateway`, `ip_prefix_length`, `id`). Remove these attributes from `docker.tf`.

1. Re-run `terraform plan`.

    ```shell
    terraform plan
    ```

    It should now execute successfully. The plan indicates that Terraform will
    update in place to add the `attach`, `logs`, `must_run`, and `start`
    attributes. Notice that the container resource will not be replaced.

1. Apply the changes. Remember to confirm the run with a `yes`.

    ```shell
    terraform apply
    ```

1. There are now several attributes in `docker.tf` that are unnecessary because
    they are the same as their default values. After removing these attributes,
    `docker.tf` will look something like the following.

    ```hcl
    # docker_container.web:
    resource "docker_container" "web" {
       name  = "hashicorp-learn"
       image = "sha256:9beeba249f3ee158d3e495a6ac25c5667ae2de8a43ac2a8bfd2bf687a58c06c9"

       ports {
           external = 8080
           internal = 80
       }
    }
    ```

1. Run `terraform plan` again to verify that removing these attributes did not
    change the configuration.

    ```shell
    terraform plan
    ```

### Verify that your infrastructure still works as expected

```shell
$ docker ps --filter "name=hashicorp-learn"
```

    You can revisit `0.0.0.0:8080` in your web browser to verify that it is
    still up. Also note the "Status" - the container has been up and running
    since it was created, so you know that it was not restarted when you
    imported it into Terraform.

### Create a Docker image resource

1. Retrieve the image's tag name by running the following command, replacing the
    sha256 value shown with the one from `docker.tf`.

    ```shell
    docker image inspect sha256:602e111c06b6934013578ad80554a074049c59441d9bcd963cb4a7feccede7a -f {{.RepoTags}}
    ```

1. Add the following configuration to your docker.tf file.

    ```hcl
    resource "docker_image" "nginx" {
      name = "nginx:latest"
    }
    ```

1. Run `terraform apply` to apply the changes. Remember to confirm the run with
    a `yes`.

    ```shell
    terraform apply
    ```

1. Now that Terraform has created a resource for the image, refer to it in
    `docker.tf` like so:

    ```hcl
    resource "docker_container" "web" {
      name  = "hashicorp-learn"
      image = docker_image.nginx.latest

    # File truncated...
    ```

1. Verify that your configuration matches the current state.

    ```shell
    terraform apply
    ```

### Manage the container with Terraform

1. In your `docker.tf` file, change the container's external port from `8080` to
    `8081`.

    ```hcl
    resource "docker_container" "web" {
      name  = "hashicorp-learn"
      image = "sha256:602e111c06b6934013578ad80554a074049c59441d9bcd963cb4a7feccede7a5"

      ports {
        external = 8081
        internal = 80
      }
    }
    ```

1. Apply the change. Remember to confirm the run with a `yes`.

    ```shell
    terraform apply
    ```

1. Verify that the new container works by running `docker ps` or visiting
    `0.0.0.0:8081` in your web browser.

    ```shell
    docker ps --filter "name=hashicorp-learn"
    ```

### Destroy resources

1. Run `terraform destroy` to destroy the container. Remember to confirm
    destruction with a `yes`.

    ```shell
    terraform destroy
    ```

1. Run `docker ps` to validate that the container was destroyed.

    ```shell
    docker ps --filter "name=hashicorp-learn"
    ```