An ultra-light, self-hosted PaaS for small VPSs. Build on GitHub Actions, deploy to your own server, keep the platform itself under 8 MB of RAM.

Rustle deploys stateless Next.js / Node apps from public or private GHCR images onto a single 1 vCPU / 1 GB VPS, with automatic HTTPS from Caddy. One Rust binary (5 MB) embeds the WebAssembly dashboard. Measured idle RSS is 5.8 MB, so the memory goes to your apps instead of the platform.

Status: pre-release. The code is complete and heavily tested against fakes and mock servers (293 tests, a headless browser test of the dashboard, an RSS gate, a run against a real Caddy). It has not yet been run on a real VPS: see docs/VERIFY_ON_VPS.md and docs/STATUS.md. Reports from real servers are the most useful contribution right now.

Why Rustle

Tiny	One static binary, SQLite, single-threaded async runtime. Idle 5.8 MB, 6.9 MB after load, 14.8 MB peak (password hashing). Hard cap 48 MB through systemd.
Builds elsewhere	Images are built by GitHub Actions. The VPS only pulls, so a 1 GB machine never runs next build.
Safe by default	The Docker socket is never mounted into Rustle. Containers get a hard RAM limit, no capabilities, no published ports, no mounts. Secrets are encrypted at rest. See docs/THREAT_MODEL.md.
Boring deploys	Pull by digest, health check, switch the Caddy route, keep the previous version for one-click rollback (with that deployment's environment). Optional zero-downtime.
Fits your server	Fresh Ubuntu or a box that already runs sites behind Caddy and Compose: the installer detects it and only adds routes.
Trustworthy updates	Self-update accepts only ed25519-signed releases and reverts automatically if the new binary does not start.

Rustle is deliberately narrow: stateless apps only (databases live elsewhere: Neon, Supabase, …), one admin user, one server. If you need multi-node orchestration, databases-as-a-service or on-server builds, tools such as Dokku, CapRover or Coolify are a better fit. Rustle is for the case where those would not leave you enough RAM.

How it works

flowchart LR
  dev[git push] --> gha[GitHub Actions<br/>build + push image to GHCR]
  gha -- "POST /api/v1/webhooks/deploy<br/>per-site token" --> rustle
  subgraph VPS
    rustle[Rustle<br/>5 MB] -- Admin API --> caddy[Caddy<br/>HTTPS]
    rustle -- filtered Docker API --> proxy[Docker socket proxy]
    proxy --> docker[(Docker)]
    caddy --> app1[site A]
    caddy --> app2[site B]
  end
  user((visitors)) --> caddy
  admin((you)) -- dashboard --> caddy

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Screenshots

Sites: state, domain and RAM per site	Deploys: history, trigger, digest, rollback
Add a site in three steps	One-time deploy token, workflow and Dockerfile ready to paste
Environment: masked, encrypted at rest	CI/CD: generated workflow for server and static Next.js
Cron: system jobs, one-shot containers, HTTP calls	Settings: password, domain, RAM budget, backups, updates

Screenshots come from the headless-browser test (scripts/ui_e2e.js) running against in-memory fake backends.

Install

Ubuntu 22.04 / 24.04, as root on the VPS:

curl -fsSL https://github.com/megabuild-dev/Rustle/releases/latest/download/rustle-installer.tar.gz | tar xz
sudo ./install/install.sh --domain admin.example.com --email you@example.com

The installer is idempotent. It creates swap if there is none, installs Docker, starts the socket proxy and Caddy, installs the release binary, prints the master key (save it: without it backups cannot be restored) and the admin password, then starts the service. Add --dry-run to see what it would do.

• Without --domain the dashboard is served on https://<server-ip> with a self-signed certificate until you set a domain in Settings. For a domain, point an A record at the server first.
• Already running sites behind a Caddy (host service or container)? Use --use-existing-caddy. Your sites stay untouched. See docs/COEXISTENCE.md, including importing sites from a site-ctl.sh setup.
• HTTPS certificates are obtained and renewed by Caddy (Let's Encrypt or ZeroSSL). Rustle only tells Caddy which hosts to serve.
• Upgrading the VPS plan needs no action: the RAM budget follows the machine.

Deploying a site: add it in the dashboard, copy the generated workflow into your repo, set the one-time token as a GitHub secret, and push.

Build from source

git clone https://github.com/megabuild-dev/Rustle && cd rustle
scripts/build-ui.sh                     # dashboard -> ui-dist/ (needs trunk and the wasm32 target)
cargo build --release -p rustle-server  # target/release/rustle
cargo test -p rustle-types -p rustle-server

docs/DEV.md covers running with in-memory fake backends (no Docker needed), configuration variables and the CLI.

Quality

• 293 tests, plus a browser end-to-end test, an RSS gate and an end-to-end run against a real Caddy.
• CRAP score below 30 for every function (enforced in CI).
• Mutation testing over the server crate; surviving mutants were fixed or documented (docs/QUALITY.md).
• Dependencies are checked for advisories and licences on every pull request (cargo deny) and kept current by Dependabot.

Documentation

What is built and what is verified	docs/STATUS.md
What still has to be checked on a real VPS	docs/VERIFY_ON_VPS.md
Threat model	docs/THREAT_MODEL.md
Installing next to existing sites and Caddy	docs/COEXISTENCE.md
Development, configuration, CLI	docs/DEV.md
Test quality: CRAP score and mutation testing	docs/QUALITY.md
Releasing and signing	docs/RELEASING.md
Implementation plan and design changes	docs/IMPLEMENTATION_PLAN.md, docs/DECISIONS_ADDENDUM.md

Brand

The logo is a leaf lifted by the wind: light enough to ride on a 1 GB server. The name is the sound leaves make. Logo, icons and the social preview are in assets/brand (MIT, like the rest of the project).

Contributing

Contributions are welcome, especially verification reports from real servers. Read CONTRIBUTING.md and the Code of Conduct. Found a security problem? Follow SECURITY.md and do not open a public issue. Changes are tracked in CHANGELOG.md.

License

MIT © 2026 megalabs-dev and Rustle contributors.

_{Keywords: self-hosted PaaS, Heroku alternative, Vercel alternative, deploy Next.js on a VPS, low memory, Rust, Caddy, Docker, GitHub Container Registry, GitHub Actions, zero downtime, rollback, WebAssembly, Leptos, SQLite.}