The standard for customising cloud instances
Cloud images are operating system templates and every instance starts out as an identical clone of every other instance. It is the user data that gives every cloud instance its personality and cloud-init is the tool that applies user data to your instances automatically.
While cloud-init started life in Ubuntu, it is now available for most major Linux and FreeBSD operating systems. For cloud image providers, then cloud-init handles many of the differences between cloud vendors automatically — for example, the official Ubuntu cloud images are identical across all public and private clouds.
cloud-init is developed and released as free software under both the GPLv3 open source license and the Apache License version 2.0. It was originally designed for the Ubuntu distribution of Linux in Amazon EC2, but is now supported on many Linux and UNIX distributions in every major cloud.
