olcf / anchor

Extensible diskless booting dracut module

Anchor Code Repository

Repo for developing shared Anchor code.

What is Anchor?

Anchor is a (secure) booting tool that will pull an image from an object store and use it to boot a diskless node. It mostly consists of a dracut module that is configured to use different pluggable methods to bootstrap authentication and download a image for a node. The main scope for Anchor is to provide an extensible framework for handling different diskless boot methods, with a primary focus on pulling data from an object store and mounting a squashfs image overlayed with a local ramdisk.

What else do I need to boot?

Honestly, a lot. Two main repositories that the clusters team rely on are our Anchor Operations repository to handle automation steps to build and deploy images, and our Chart repository to handle needed services that communicate with Anchor. Copies of the public version of these two repositories are stored under the contrib folder. Management of these services and operations can be done in a thousand different ways, and is left to each individual organization to solve however they see best.

Repository Structure

Path	Feature
src	Dracut module source directory
doc	Documentation pages
contrib	Auxiliary directory containing contributions that are not part of anchor proper. This includes common CI configurations, build script examples, etc.
build.sh	Script to build RPM.

Current modules

Auth	Provided By	Description
ACME	lib/lib_acme.sh	Automatically issue certificates from a trusted CA to a node per RFC 8555.
SSH	lib/lib_dropbear.sh	Start a dropbear server with a trusted root login key, wait until files put in place. Optionally send client network data to a URL.
NFS	lib/lib_nfs.sh	Mount an NFS share to retrieve the files needed for authentication.
None		Do not authenticate. Skip to the next stage.

Image	Provided By	Description
squashfs	lib/lib_squashfs.sh	Download squashfs image from an rsync server or mutual TLS HTTP server.
buildah	lib/lib_buildah.sh	Download an uncompressed image from a docker registry. Build a squashfs live on boot.

Change log

• 0.1.5 - Add NFS authentication module, add URL polling to dropbear
• 0.1.4 - Add rngd binaries and bash library to populate /dev/random prior to ACME and curl operations
• 0.1.3 - Remove BOOTIF requirement for setting root=ok
• 0.1.2 - Add url-lib dracut module dependency to install curl with needed HTTPS libraries
• 0.1.1 - First fully-featured release following the migration to a shared code repository