uxc-stack: add the container stack engine

2026-08-21T04:34:10Z

Add uxc-stack, a ucode engine that instantiates and tears down a multi- container stack from a template. "up " loads a stack template returning compose(api), which declares named instances drawn from shared image layers, then writes one autostart registration per instance and triggers bring-up by a ubus event procd reconciles through the boot path, avoiding a synchronous create that would serialise the stack on each member's start. "down " is driven from the persistent registrations (origin "stack:"), not the template, since apk removes the template before pre-remove runs. Addressing is deterministic and state-free, derived by FNV-1a from names: a per-instance host-uid offset strided by 64k so re-created instances keep their data-volume ownership, and a backhaul /24 within RFC 2544 198.18.0.0/15. The engine writes a shared /etc/hosts (retaining localhost) for resolver-free discovery, plus per-instance annotation sidecars uxc-net merges over the image's baked annotations. Secrets are referenced via generate@ directives uxc materialises, and bound idmapped rather than copied. On teardown, data volumes and their paired generated secrets are kept and reported for manual removal. Signed-off-by: Daniel Golle

procd/uxc-stack, branch master

uxc-stack: add the container stack engine