How do I create a Databricks personal access token for unattended authentication and what environment variables do I need to set?
To create a Databricks personal access token for unattended authentication, you can follow these steps:

1. Log in to your Databricks workspace.
2. Click on your username in the top right corner and select "User Settings" from the dropdown menu.
3. Go to the "Access Tokens" tab.
4. Click on the "Generate New Token" button.
5. Enter a description for the token and select the desired lifetime.
6. Click on the "Generate" button.
7. Copy the generated token.

To use the personal access token for unattended authentication, you need to set the following environment variables:

* `DATABRICKS_HOST`: The hostname of your Databricks workspace (e.g., `https://<workspace-url>`).
* `DATABRICKS_TOKEN`: The personal access token you generated.

You can set these environment variables in your operating system or CI/CD system provider's documentation. For example, in a Unix-based system, you can use the `export` command:

```bash
export DATABRICKS_HOST=<workspace-url>
export DATABRICKS_TOKEN=<personal-access-token>
```

Remember to replace `<workspace-url>` and `<personal-access-token>` with your actual Databricks workspace URL and personal access token, respectively.