Adds a single global concurrency cap on the data-plane dispatch path:
- orchestrator-core::gate::ExecutionGate wraps tokio::Semaphore.
Non-blocking try_acquire — no queue. PICLOUD_MAX_CONCURRENT_EXECUTIONS
env var (default 32) sets the cap.
- LocalExecutorClient acquires a permit before spawn_blocking; the
permit drops with the future so the slot returns automatically.
- On refusal, ExecError::Overloaded { retry_after_secs: 1 } surfaces
upward. ApiError::IntoResponse already maps that to 503 with a
Retry-After header (landed in the previous commit alongside the
variant itself).
- picloud binary constructs the gate once at build_app and shares it
with LocalExecutorClient.
The cap exists so a Rhai script storm can't drain the blocking-thread
pool — pushing back hard beats letting requests pile up against a
finite worker count. Per-app / per-script caps stay deferred until a
real workload demands them.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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.