#Anemos

Anemos is an open source infrastructure management research project.

Its goals are:

• To promote (but not enforce) a declarative approach to deployments, ideally culminating in immutable deployments
• To facilitate bare-metal-level infrastructure-as-code in small environments, where e.g. a full-blown PXE-boot infrastructure is not viable or overkill
• Provide extensibility into a full-blown asset management platform

In its current state, Anemos is a set of tools that allow you to deploy a system image described in code (e.g. a script that runs setup-alpine) to a host (bare-metal or virtual) without the need for external infrastructure (like PXE boot) or physical access (like booting a live system from USB).

One absolutely welcome side-effect of how Anemos works is that it makes it "easy" (some caveats apply, of course) to deploy a custom distribution to a VPS where the provider only offers a limited choice of distributions. See the demo below.

🔴🔴🔴 NOTE: Anemos is very young and work in progress. It performs actions that can potentially leave your server in a broken or unexpected state. When using it for the first time on a server, make sure you:

1. Understand the actions it will perform, and
2. have the means to recover (physical access, serial console access, remote re-imaging, etc)

#How it works

A deployment with Anemos makes use of the following components:

• A user-supplied payload: this is the codified description of what to deploy
• An initramfs, which performs the deployment
• A CLI tool, which - on the host to be deployed - generates the initramfs and boots it, thereby triggering the deployment

The components are described in more detail below. The deployment process works as follows:

• The user creates a payload describing the desired deployment
• The host to be deployed to must have:
  • The Anemos CLI
  • Access to the kernel, base initramfs, and payload - either locally or via network
  • A proper Anemos configuration file (see comments in the example)
• The Anemos CLI is used on the host to:
  • Generate the final initramfs to be used
  • Boot the generated initramfs
• The initramfs, once booted, will automatically perform the deployment as specified in the payload

#Components

#Initramfs

The final initramfs is generated on the host to include the deployment payload, network configuration, and firmware. But the deployment mechanics are implemented in the base initramfs.

#CLI tool

The CLI tool is a simple shell script with a single configuration file. There are no packages yet, so it needs to be installed manually for now.

#Payload

The payload is a gzipped tarball of one of two things:

• An IMGBUILD - like e.g. the demo payload
• A custom executable file called deploy, along with whatever other files are needed

A simple example of a custom payload could be a script that simply runs setup-alpine with some predefined answers.

#How to use it

The project is still very young. There are no packages, no versioning, no proper distribution of artifacts. That said, I uploaded everything you need to get started:

NOTE: Doing this will overwrite the host's disk! Do it in a throw-away VM, or something you can easily reset to a state of your liking.

# Prerquisites: make sure you have zstd and cpio installed
wget https://anemos.io/demo/anemos      # The CLI tool
wget https://anemos.io/demo/anemos.conf # An example config file
chmod +x anemos
# Study the config file and edit to your liking
./anemos -c anemos.conf

#Demo

If you'd rather see it in action on someone else's machine, here is a screencast where you can observe the following:

• I use the serial console of a LeaseWeb VPS running a freshly provisioned Debian
• After installing zstd I perform the steps outlined above
• The machine reboots, initially seemingly back into Debian
• After loading the initramfs, an Alpine system boots
• Once OpenRC is done, the deploy starts (pacstrap via makeimg)
• The machine reboots again
• A fully functional Arch Linux comes up (LeaseWeb does not offer Arch Linux images for their VPS)