Dokku is a self-hosted Platform-as-a-Service (PaaS) that leverages Docker to automate the building, deployment, and management of applications. Designed as a minimal alternative to commercial PaaS offerings like Heroku, Dokku enables developers to deploy applications using Git pushes without needing deep infrastructure expertise. It abstracts away the complexity of container orchestration while retaining full control over the underlying server environment. Dokku is ideal for small to medium teams, startups, or individual developers who want the convenience of a PaaS without relying on third-party cloud providers or paying for over-provisioned services.
Built with Shell and designed to run on minimal VMs, Dokku integrates seamlessly with existing SSH workflows and supports buildpacks, Dockerfiles, and custom deployment pipelines. Its simplicity makes it a popular choice for those seeking to avoid the complexity of Kubernetes or Nomad while still benefiting from containerized deployments.
What You Get
- Git-based deployment - Push your application code via Git to trigger automated builds and deployments using buildpacks or Dockerfiles, mirroring Heroku’s workflow.
- Built-in Docker integration - Automatically containers your apps using Docker, with isolated environments for each application and automatic port mapping.
- Domain management - Configure custom domains globally or per-app using the
dokku domains:set-global and dokku domains:set <app> commands.
- SSH key authentication - Securely manage deploy access via SSH keys using
dokku ssh-keys:add to register public keys for deployment users.
- Plugin system - Extend functionality with official and community plugins (e.g., PostgreSQL, Redis, letsencrypt) via
dokku plugin:install.
- Automatic build detection - Detects application type (Node.js, Python, Ruby, etc.) via buildpacks or Dockerfile and builds accordingly without manual configuration.
- Process scaling - Scale application processes using
dokku ps:scale <app> <process>=<count> to manage web, worker, or background processes.
Common Use Cases
- Building a Node.js SaaS dashboard - Developers deploy full-stack applications using
git push dokku main and automatically get HTTP routing, environment variables, and process management without managing containers manually.
- Creating a self-hosted API backend - Teams running microservices on a single VPS use Dokku to deploy multiple apps (e.g., auth service, payment gateway) with isolated containers and custom domains per service.
- Problem → Solution flow: Need Heroku-like deployment without monthly fees - Users tired of Heroku’s cost or limitations install Dokku on a $5/month VPS and replicate the same
git push workflow with full data control.
- Team DevOps workflows for small startups - Junior developers push code without needing infra knowledge, while senior engineers retain control over server resources and security policies.
Under The Hood
Dokku is an open-source Platform-as-a-Service built on Docker and Bash, offering a lightweight, Heroku-like deployment experience with fine-grained control over containerized applications. It enables developers to manage and scale applications using a command-line interface while leveraging system-level automation and plugin extensibility.
Architecture
The project adopts a modular, layered architecture centered around Docker containers and shell-based orchestration.
- The system is structured with a core engine and extensive plugin support, enabling flexible customization without altering the main codebase.
- Configuration and runtime behaviors are managed through shell scripts, Makefiles, and declarative files that define service interactions.
- Docker containers serve as the primary deployment unit, aligning with a container-first design that integrates well with NGINX and OpenResty.
- Service management is handled via runit and shell-based hooks, allowing for modular and extensible runtime behavior.
Tech Stack
The project utilizes a multi-language tech stack focused on system-level automation and containerization.
- Built primarily in Go for core logic, with shell scripts handling most operational tasks and Dockerfile definitions for container environments.
- Relies on Docker, nginx, OpenResty, and runit for deployment and service management, with Ubuntu/Debian packages for system integration.
- Build and development workflows are driven by Makefiles, Dockerfiles, and custom Bash automation scripts.
- A comprehensive test suite includes integration tests and shell-based validation across various application types.
Code Quality
The codebase reflects a mixed quality profile with strong testing practices and some structural inconsistencies.
- Extensive test coverage is present across multiple deployment scenarios, with integration and shell-based testing being the primary methods.
- Error handling follows standard patterns but could benefit from more robust propagation in some core components.
- Code consistency varies between Go and shell scripting, with shell scripts showing more uniform structure than Go modules.
- Technical debt is evident in documentation formatting and some core implementation approaches, though overall maintainability remains reasonable.
What Makes It Unique
Dokku distinguishes itself through its plugin-driven architecture and low-level system automation capabilities.
- Its modular plugin system allows developers to customize deployment workflows without modifying core logic, offering high adaptability.
- System-level automation is achieved through Bash and shell scripting, enabling granular control over container orchestration.
- Seamless integration with Docker and NGINX delivers a production-ready stack while maintaining simplicity for developers.
- The command-line interface abstracts complex infrastructure operations, making advanced DevOps practices more accessible.