Private cloud, public cloud, hybrid cloud, multi-cloud… the variety of locations, platforms and physical substrate you can start a cloud instance on is vast. Yet once you have selected an operating system which best supports your application stack, you should be able to use that operating system as an abstraction layer between different clouds.

However, in order to function together an operating system and its cloud must share some critical configuration data which tells the operating system how to ‘behave’ in the particular environment. Separating out this configuration data from the operating system and the underlying cloud is the key to effortlessly launching instances across multi-cloud.

Cloud-init provides a mechanism for separating out configuration data from both the operating system and the execution environment so that you maintain the ability to change either at any time. It serves as a useful abstraction which ensures that the investments you make in your application stack on a specific operating system can be leveraged across multiple clouds.

This whitepaper will explain:

• The background and history behind the cloud-init open source project
• How cloud-init is invoked and how it configures an instance
• How to get started with cloud-init