How to Provide User Data During Droplet Creation

User data is arbitrary data, often a script, that you can supply to a Droplet during creation. [cloud-init](https://cloud-init.io/) is a tool that applies user data to automatically configure cloud servers like Droplets.

When you provide user data to a Droplet with cloud-init, cloud-init consumes the user data, which it can use to perform tasks as the root user during the Droplet’s first boot. This is helpful for automation setup for tasks like creating new users, customizing firewall rules, installing applications, and configuring SSH keys.

About cloud-init

cloud-init accepts cloud-config files or any script that can be interpreted by the Droplet, like a Bash script.

cloud-init is available on DigitalOcean’s latest Ubuntu and CentOS images. You can define user data for images that do not support cloud-init, but the user data is not consumed automatically on first boot.

Providing User Data

You can provide user data to a Droplet during creation via the DigitalOcean Control Panel, the API, or doctl, the CLI client.

• To provide user data when creating a Droplet via the DigitalOcean Control Panel, on the Droplet creation page, above the Finalize Details section, click + Advanced Options. In the section that opens, check the box next to Add Initialization scripts. Add your user data in the box that appears.

• To provide user data when creating a Droplet via the DigitalOcean API, use the user_data field in the Droplet creation POST request.

• To provide user data when creating a Droplet via doctl, the DigitalOcean CLI, use the --user-data or --user-data-file flags when calling doctl compute droplet create.

You cannot modify user data after a Droplet is created.

Debugging User Data

To see how a cloud-init file uses the provided user data, view the /var/log/cloud-init-output.log file:

cat /var/log/cloud-init-output.log | grep userdata

The file logs output from cloud-init so you can view warnings, error messages, and debug information.

More Information

cloud-init has both reference documentation and examples to see which properties of your Droplet you can automatically configure upon deployment.

an introduction to cloud-config scripting

this tutorial explains the format and usage of cloud-config files, which are special scripts designed to be run by the cloud-initprocess for initial configuration on the first boot of a server.

how to use cloud-config for your initial server setup

this tutorial uses the digitalocean metadata service and cloud-config files to automate initial server setup for a ubuntu droplet.