Harness Open Source is a comprehensive, open source DevOps platform that unifies source code management, continuous integration and delivery (CI/CD), hosted development environments called Gitspaces, and artifact registries into a single system. Built as the evolutionary successor to Drone, it extends beyond CI by adding full SCM capabilities and developer-centric tooling. Designed for engineering teams seeking an integrated, self-hosted alternative to commercial platforms, Harness enables end-to-end workflow automation—from code commit to deployment—without vendor lock-in. It targets DevOps engineers, platform teams, and developers who want control over their toolchain while maintaining scalability and extensibility.
What You Get
- Source Control Management (SCM) - Built-in code hosting with Git repositories, branch protection, pull requests, and access controls—eliminating the need for separate platforms like GitHub or GitLab.
- CI/CD Pipelines - Automated build, test, and deployment workflows powered by a Drone-compatible engine, allowing seamless migration from existing Drone setups with minimal changes.
- Hosted Developer Environments (Gitspaces) - On-demand, cloud-based development environments tied to repositories, enabling consistent, reproducible dev setups without local configuration overhead.
- Artifact Registries - Integrated container and package registries to store, manage, and version build outputs (e.g., Docker images) directly within the platform.
- REST API & Swagger UI - Full-featured REST API with auto-generated OpenAPI specs accessible at /swagger and /registry/swagger for programmatic automation and integration.
- Command-Line Interface (CLI) - Basic CLI tools for authentication, token generation, and server management, enabling automation of user and access operations without UI interaction.
Common Use Cases
- Building a self-hosted CI/CD pipeline with integrated code hosting - Teams avoiding SaaS platforms use Harness to host repositories and run pipelines internally, ensuring data residency and compliance with enterprise policies.
- Creating a developer environment platform for distributed teams - Engineering managers deploy Gitspaces to provide instant, pre-configured dev environments for onboarding new engineers or running PR previews without local setup.
- Migrating from Drone to a full DevOps platform - Organizations using Drone for CI now extend their pipeline capabilities with SCM and artifact management without switching tools, leveraging Harness’s backward-compatible pipeline engine.
- DevOps teams managing microservices with internal registries - Teams building 50+ microservices use Harness to centralize Docker image storage and automate build-triggered pushes, reducing dependency on external registries like Docker Hub or Harbor.
Under The Hood
The project is a comprehensive GitOps and CI/CD platform built with a monolithic architecture that separates frontend and backend concerns while leveraging modern web and cloud-native technologies. It provides a robust foundation for managing infrastructure, pipelines, and deployment workflows through a modular and extensible system.
Architecture
This codebase adopts a monolithic structure with distinct frontend and backend layers, enabling centralized control over core features such as authentication, pipelines, and Git operations.
- The system is organized into modules based on functionality, ensuring clear separation between API controllers, service layers, and domain-specific components.
- Design patterns like factory and abstract factory are applied in the frontend to support component extensibility and consistent UI behavior.
- State management and service-based communication are used to coordinate interactions across frontend components and backend services.
Tech Stack
The project is a polyglot system built with Go for backend services and TypeScript/React for the frontend UI, incorporating modern development practices.
- The backend is powered by Go 1.24.x, while the frontend utilizes TypeScript with React and module federation for UI composition.
- Key dependencies include BlueprintJS, Harness UI libraries, RESTful-react, Lodash, and Monaco Editor for enhanced functionality.
- Development tools such as Webpack, Docker, Makefiles, and TypeScript ensure efficient build processes and type safety.
Code Quality
The codebase demonstrates a mature testing approach with integration and load tests, alongside consistent error handling and naming practices.
- Extensive use of Jest and Cypress ensures comprehensive unit and end-to-end test coverage across both frontend and backend components.
- Custom error types and standardized checks provide reliable handling of authentication, authorization, and runtime failures.
- While code style and patterns are mostly consistent, some technical debt remains due to monolithic structure and tight coupling between modules.
What Makes It Unique
The Harness project stands out through its advanced abstraction and authorization model tailored for Git-based workflows and infrastructure management.
- It introduces a sophisticated approach to securing resource access in diverse deployment environments, integrating seamlessly with GitOps practices.
- The system provides extensible frameworks for managing pipelines and infrastructure, enabling flexible and scalable CI/CD workflows.
- Its unique blend of API design, load testing strategies, and modular architecture differentiates it from generic CI/CD platforms.