by Josef Spillner
The Elastic Compute Cloud (EC2) offered by AWS as public commercial service has been one of the first and probably the seminal service for the research on cloud applications and infrastructure. From an application perspective, hosting in EC2 means wrapping the application into one of the provided virtual machine (VM) images and instantiating it in sufficient numbers (e.g. with autoscaling). Ultimately, for custom applications, it also possible to import custom VM images. This involves creating the machine image, testing it on a local hypervisor (KVM, Xen, VirtualBox, …) or in a local cloud stack (OpenStack, CloudStack, OpenNebula, …), then copying the image into the Simple Storage Service (S3) (in a reliable manner), initiating the import process, and waiting for the VM image called Amazon Machine Image (AMI) to become available. This import process is not well-documented and regularly causes high effort with application providers. Hence, this blog post offers a detailed walk-through and points out common pitfalls.