MechaCat02 80a0d31cd2 fix(files): make file writes transactional and close a quota bypass
Audit #6 and #8 for the last of the three stores, plus a bypass found on
the way.

**#6.** create/update/delete wrote the metadata row, then emitted
best-effort, so an outbox failure left a committed file whose trigger never
fired. `atomic_write::FilesWriter` commits the metadata row and the fan-out
together.

Files are the one store where the ordering is subtle, because the BYTES live
on disk and cannot join a transaction:

  * create/update — blob first, then commit metadata + fan-out. A rollback
    unlinks the blob. (A crash at that exact point still orphans it; that
    hazard predates this change — the repo already wrote the blob and then
    inserted the row in a separate, failable statement — and the orphan is
    inert, referenced by nothing.)
  * delete — commit the metadata removal + fan-out FIRST, then unlink. The
    reverse order would destroy the bytes of a row that a rollback keeps,
    leaving a file that can never be read.

**#8.** `GroupFilesService::create` read `total_bytes` on one connection and
wrote on another, so concurrent uploads each saw the same pre-write total and
together overshot the ceiling. This is the worst instance of the race in the
codebase: the ceiling is DISK (10 GiB by default) and one file may be 100 MB,
so a racing fleet overshoots by gigabytes. `PostgresGroupFilesWriter` takes
the per-group advisory lock (on its own `files` key) across the check and the
write.

**The bypass.** `GroupFilesService::update` checked NO quota at all — so a
1-byte file could be updated to a 100 MB one without the ceiling ever being
consulted, repeatedly, for unbounded disk. It now checks the projected total
(the replaced file's bytes subtracted in SQL, so a same-size-or-smaller
update near the cap still goes through).

Also drive-by: `queue_e2e` asserted the ack the instant the marker appeared,
but the marker is written DURING the handler and the ack happens after it
returns — a zero-tolerance race. It polls now. (This does not fix the
suite's flakiness, which reproduces on the pre-pass commit too.)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-07-14 20:09:03 +02:00

PiCloud

A lightweight, self-hosted, event-driven serverless compute platform. Upload a Rhai script, get an HTTP endpoint. Designed to run on a single modest server with no idle CPU cost, and to scale out to a small cluster when you need it.

Status: Phase 1 — MVP scaffolding in progress.

The authoritative design lives in serverless_cloud_blueprint.md.

Why

Existing serverless platforms are either cloud-locked, heavyweight, or both. PiCloud aims for the opposite end of the spectrum: one binary, one database, one reverse proxy — running on hardware you already own.

Architecture (one paragraph)

PiCloud splits into three logical services — manager (control plane: scripts, schedules, dashboard), orchestrator (per-node event ingress and dispatch), and executor (per-node Rhai sandbox) — each backed by a *-core Rust library. In MVP they run in a single process; in cluster mode they run as three binaries with one manager and one orchestrator + executor per node. Caddy fronts everything; PostgreSQL is the single source of truth.

See CLAUDE.md for working notes and serverless_cloud_blueprint.md for the full design.

Quick Start

Coming as scaffolding lands. For now:

# Rust toolchain (pinned via rust-toolchain.toml)
cargo check --workspace

# Run the all-in-one MVP binary (once main.rs is wired up)
cargo run -p picloud

Repository Layout

crates/
  shared/                 cross-cutting types
  executor-core/          Rhai engine + sandbox
  orchestrator-core/      event ingress, dispatch
  manager-core/           control plane
  picloud/                MVP all-in-one binary
  picloud-{manager,orchestrator,executor}/   cluster-mode binaries (skeleton)
dashboard/                SvelteKit
caddy/                    Caddyfile
docker/                   Dockerfiles
docs/
  git-workflow.md         Trunk-based workflow

Contributing

See docs/git-workflow.md for the branching and commit conventions. TL;DR: trunk-based, short-lived branches, Conventional Commits, no force-pushing main.

License

TBD.

Description
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