Dokku

Dokku has been the gold standard self-hosted Heroku alternative for over a decade — git push to deploy, a rich plugin ecosystem (official plugins for Postgres, Redis, MySQL, MongoDB, Let's Encrypt), and a well-tested single-server PaaS architecture. Control is via SSH-based CLI commands rather than a REST API, which makes it suitable for agents that can execute shell commands on the host. Confidence is docs-derived.

No REST API — Dokku is controlled via SSH CLI. Commands: ssh dokku@{host} apps:create {app} (create app). git push dokku {app} main (deploy). ssh dokku@{host} config:set {app} KEY=VALUE (set env vars). ssh dokku@{host} ps:scale {app} web=3 (scale). ssh dokku@{host} domains:add {app} example.com (add domain). Plugin management: dokku plugin:install {url}. For agent use: exec SSH commands programmatically or use Dokku HTTP API plugin (third-party).

SSH key auth: public key added to Dokku host authorized keys. Commands executed via SSH. HTTPS enforced via Let's Encrypt plugin (letsencrypt:enable {app}). No API token — all control via SSH. Operators should manage authorized keys carefully.

Deployment failures: git push returns error on build failure. Container health: dokku ps:report {app}. Service crashes: Dokku restarts containers based on restart policy. Single-server architecture: no HA by default. Dokku project reliability: long-standing open-source with stable releases.

dokku.com/docs provides comprehensive CLI reference, getting started, plugin installation guides, and deployment patterns. Getting started: install on Ubuntu 22.04 in under 5 minutes (script provided), first git push deploy in under 10 minutes. Open-source MIT (GitHub: dokku/dokku). Large community via Dokku Discourse and GitHub.