The Deployment Scripts feature is being phased out with the introduction of cloud-config for supported operating systems in its place.
An option to 'Enable cloud-init User Data' will be presented on the server creation form when an operating system that supports cloud-config has been selected for installation.
Checking this option enables the use of cloud-config scripts, as well as plain shell scripts, and includes.
It does not support variables or provide a web interface in the same manner that the retired deployment scripts facilities did.
The following documentation provides detailed examples of #cloud-config usage.
https://cloudinit.readthedocs.io/en/latest/reference/examples.html
It is possible to enter basic shell script starting with '#!/bin/bash' or python code using '#!/bin/python3' for example. Consult the following documentation for further information.
https://cloudinit.readthedocs.io/en/latest/explanation/format.html
The use of #include is supported as well. This will allow you to enter the URL(or URLs, one per line) of a script or file hosted at an external repository such as Github. The #include feature supports URLs pointing to gzipped, mime-multipart, or plaintext content.