ssb-pacman

Objective

• enable offline instalation of packages
• keep old version of archlinux and archlinuxarm packages
• sync metadata via ssb
• allow peer-to-peer installations
• enable reproducable rootfs builds
• mimic a local mirror server that pacman can use
• create custom syncdb on demand, fitlering packages not in a given shrinkwrap file

Installation

Install sbot and ssb-pacman

npm -g i scuttlebot-release
mkdir -p ~/.ssb-pacman/node_modules
cd ~/.ssb-pacman/node_modules/
git clone [e-mail]:regular/ssb-pacman
cd ssb-pacman
npm i
npm -g link
cp sbot.config ../../config
export ssb_appname=ssb-pacman
sbot start

in a different terminal

ssb-pacman-sync

This will take a long time to finish. You can use the scripts in monitor to watch the progress. (use tmux for a full dashboard-style experience)

Meanwhile, in yet another terminal:

ssb-pacman-init-keyring

Install a minimal system in directory root

ssb-pacman-bootstrap root

This downloads and extracts the latest version of pacman and then runs it, so it can re-install itself properly (i.e. withe running package-specific .INSTALL scripts and pacman hooks, both witch are not done by the initial extract pass) This results in a clean, minimal system with a working package manager that uses the secure scuttlebutt network as its "mirror server".

Use pacman to install a packages with dependencies in the chroot

# TODO: support multiple package names
ssb-pacman-install vim root
ssb-pacman-install sed root
ssb-pacman-install grep root

A pacman post-transaction hook is installed in the target root, that records the exact hashes of installed packages. This is called the "shrinkwrap file". It's purpose is similar to package-lock.json or npm's shrinkwrap file.

Create shrinkwrap file

sudo arch-chroot /ssb-pacman-shrinkwrap

You can enter the chroot to test stuff out.

sudo arch chroot

TODO

• bindings for vercmp instead of spawning the binary

• check SHA before adding blob

• clean up bootstrap

• clean up signing (rename to keyring-setup)

• rename install.sh to extract

• unified binary

• sbot pacman.startSession ID returns stream of events

• sbot pacman.applyShrinkwrap --session ID write shrinkwrap file into session

• sbot pacman.getAddress --session ID

Surprises

• arch=any packages like "archlinux-keyring" are in all of the sync databases for each architecture. However, they actaully have different SHA256SUM entries in the sync db. So, we can not de-dupe based on SHA (or blobid). The reason for this is most likely the inclusion ov BUILDDATE in the metadata.

IDEAS

Reducing space requirements

Because all packages are compressed individually, we cannot take advantage of any overlap of binaty data between packages or differnt versions of packages. (First being relevant for data contained in packages for differnt architecture, latter being relevant for patches and bug fixes that only affect a few files in a big package)

One way to solve this could be to put the blob store onto a filesystem that has de-dupe and compression capabilites and then uncompress packages before storing them. We should set up an experiment to test this theory.