0.12.0 — a GitHub runner that removes itself after one job

Private repositories on GitHub Free get 2000 hosted Actions minutes a month;
once they are used up, every job stays queued. Self-hosted runners are not
affected. 0.12.0 runs them on plain Aleph VMs: one command starts a VM, it
takes one job, and then it forgets its own INSTANCE (#191, #192, #195).

pnpm relay-button gh-runner up --repo owner/name

Setup, step by step: Run GitHub Actions jobs on Aleph (#193).

The image

@le-space/rootfs gains the github-runner profile:

• Ubuntu 24.04, the system of GitHub's own ubuntu-24.04 runners, with
  actions-runner 2.338.0 (pinned, sha256-checked, updates off), Node.js 24,
  Docker and rootfs build tools. It carries no credential.
• The published STORE is
  9ddeabdb5a6ec23f5b6676f034a84d73a2bb3b2c912d3f736bab932fe33951cd
  (963 MiB, close to Aleph's 1 GiB upload limit).
• Debian 12 lacked the glibc (2.38) the aleph CLI release binary needs.
  Debian 13's cloud image looped in GRUB on Aleph. Growing the root partition
  with virt-resize produced an image that never came up, so it is grown in
  place with growpart. The published image was booted under QEMU to a
  login prompt before it was uploaded; the build workflow does not do that
  yet.

One job, then gone

• The launcher asks GitHub for a just-in-time config: one runner, one
  job, unable to register another. The guest deletes it as soon as the
  runner has read it. A just-in-time runner gets only the labels it is
  given, so the launcher always adds self-hosted, Linux and X64.
• After the job the VM sends FORGET for its own INSTANCE on behalf of the
  runner wallet and powers off. Measured: the FORGET came 8 seconds after the
  job, and the scheduler showed the allocation gone.
• The poweroff always comes, also when FORGET fails. A TTL timer runs from
  boot, so a VM that never gets a config still powers off.
• janitor erases and forgets what is left, and deregisters offline runners
  on GitHub. A failed up removes INSTANCEs of its name. Aleph can still
  place one later, once credits free up, which the janitor then catches.

What Aleph requires, measured

• The forget key needs INSTANCE as well as FORGET. Aleph lets a
  delegate forget only messages it could have created itself; with FORGET
  alone the VM's FORGET was rejected. Job code can read the key, so the
  runner VMs belong to a dedicated wallet with a small balance.
• A day of credits per running VM. Aleph accepts a new VM only while the
  wallet could pay a day of runtime for every VM it runs. A default runner
  costs about 28,500 credits an hour, so each concurrent runner needs about
  684,000 credits in reserve. Only the time a VM runs is charged.

Proven on a real workflow

A private repository's backup-and-restore round trip ran on two of these
runners while its hosted minutes were blocked. It started two confidential
VMs, backed up to Filecoin Calibration and restored with a piece-CID check.
Both runner VMs forgot themselves and nothing was left.

Docs

• Social preview cards for shared links: a site card, and one for the runner
  pages (#194).
• The launcher is the repository CLI (pnpm relay-button gh-runner, in
  scripts/aleph-github-runner.mjs), used from a checkout. It is not an npm
  binary, and @le-space/node does not export its helpers. On npm, the
  github-runner profile ships in @le-space/rootfs under reference/.