cloud: add terraform migrate cluster resource doc

TOC-tidb-cloud.md

@@ -359,6 +359,7 @@
     - [Use Backup Resource](/tidb-cloud/terraform-use-backup-resource.md)
     - [Use Restore Resource](/tidb-cloud/terraform-use-restore-resource.md)
     - [Use Import Resource](/tidb-cloud/terraform-use-import-resource.md)
+    - [Migrate Cluster Resource](/tidb-cloud/terraform-migrate-cluster-resource.md)
   - [Vercel](/tidb-cloud/integrate-tidbcloud-with-vercel.md)
   - [Zapier](/tidb-cloud/integrate-tidbcloud-with-zapier.md)
 - Reference

tidb-cloud/terraform-migrate-cluster-resource.md

@@ -0,0 +1,87 @@
+---
+title: Migrate Cluster Resource to Serverless or Dedicated Cluster Resource
+summary: Learn how to migrate a cluster resource to a serverless or dedicated cluster resource.
+---
+
+# Migrate Cluster Resource to Serverless or Dedicated Cluster Resource
+
+Starting from TiDB Cloud Terraform Provider v0.4.0, the `tidbcloud_cluster` resource is replaced by two new resources: `tidbcloud_serverless_cluster` and `tidbcloud_dedicated_cluster`. If you are using TiDB Cloud Terraform Provider v0.4.0 or a later version, you can follow this document to migrate your `tidbcloud_cluster` resource to the `tidbcloud_serverless_cluster` or `tidbcloud_dedicated_cluster` resource. 
+
+> **Tip:**
+>
+> The steps in this document use the configuration generation feature of Terraform to simplify the migration process by automatically recreating the `.tf` configuration for your cluster resource. To learn more about it, see [Generating configuration](https://developer.hashicorp.com/terraform/language/import/generating-configuration) in Terraform documentation.
+
+## Prerequisites
+
+- Upgrade to [TiDB Cloud Terraform Provider v0.4.0 or later](https://registry.terraform.io/providers/tidbcloud/tidbcloud/latest)
+
+## Step 1. Identify the `tidbcloud_cluster` resource to migrate
+
+1. List all `tidbcloud_cluster` resources:
+
+    ```shell
+    terraform state list | grep "tidbcloud_cluster"
+    ```
+
+2. Choose a target cluster resource to migrate and get its cluster `id` for later use:
+
+    ```shell
+    terraform state show ${your_target_cluster_resource} | grep ' id '
+    ```
+
+## Step 2. Remove the existing resource from the Terraform state
+
+Remove your target cluster resource from the Terraform state:
+
+```shell
+terraform state rm ${your_target_cluster_resource}
+```
+
+## Step 3. Delete the configuration of your target cluster resource
+
+In your `.tf` file, find the configuration of your target cluster resource and delete the corresponding code.
+
+## Step 4. Add an import block for the new serverless or dedicated cluster resource
+
+- If your target cluster is TiDB Cloud Serverless, add the following import block to your `.tf` file, replace `example` with a desired resource name, and replace `${id}` with the cluster ID you get from [Step 1](#step-1-identify-the-tidbcloud_cluster-resource-to-migrate):
+
+    ```
+    # TiDB Cloud Serverless
+    import {
+      to = tidbcloud_serverless_cluster.example
+      id = "${id}"
+    }
+    ```
+
+- If your target cluster is TiDB Cloud Dedicated, add the following import block to your `.tf` file, replace `example` with a desired resource name, and replace `${id}` with the cluster ID you get from [Step 1](#step-1-identify-the-tidbcloud_cluster-resource-to-migrate):
+
+    ```
+    # TiDB Cloud Dedicated
+    import {
+      to = tidbcloud_dedicated_cluster.example
+      id = "${id}"
+    }
+    ```
+
+## Step 5. Generate the new configuration file
+
+Generate the new configuration file for the new serverless or dedicated cluster resource according to the import block:
+
+```shell
+terraform plan -generate-config-out=generated.tf
+```
+
+Do not specify an existing `.tf` file name in the preceding command. Otherwise, Terraform will return an error.
+
+## Step 6. Review and apply the generated configuration
+
+Review the generated configuration file to ensure it meets your needs. Optionally, you can move the contents of this file to your preferred location.
+
+Then, run `terraform apply` to import your infrastructure. After applying, the example output is as follows: 
+
+```shell
+tidbcloud_serverless_cluster.example: Importing... 
+tidbcloud_serverless_cluster.example: Import complete 
+
+Apply complete! Resources: 1 imported, 0 added, 0 changed, 0 destroyed.
+```