Concourse CI
Concourse CI is an open-source continuous integration and delivery system built around a pipeline model of resources, jobs, and tasks that all run in isolated containers.
Definition
Concourse CI is an open-source continuous integration and delivery system built around a pipeline model of resources, jobs, and tasks that all run in isolated containers.
Overview
Concourse takes a distinctive approach among CI/CD tools by modeling everything as containerized, stateless steps. Pipelines are defined declaratively in YAML around three core concepts: `resources` (external things a pipeline interacts with, like a Git repository, Docker image, or S3 bucket), `jobs` (a sequence of steps that use resources), and `tasks` (individual containerized units of work within a job). Every task runs inside its own container, so builds are reproducible and don't depend on state left over on a shared build agent. Because resources are pluggable (via 'resource types,' themselves just container images implementing a small interface), Concourse can be extended to interact with almost any external system without needing plugins baked into the CI server itself, in contrast to plugin-heavy CI tools like Jenkins. Its web UI visualizes pipelines as a graph of jobs and their dependencies, making it easy to see how changes flow from source through build, test, and deployment stages. Concourse originated at Pivotal and has been closely associated with the Cloud Foundry ecosystem, where it is commonly used to build and release Cloud Foundry components themselves, though it is a general-purpose CI/CD system usable for any containerized pipeline. It is often mentioned alongside GitLab CI in this space.
Key Features
- Declarative YAML pipelines built from resources, jobs, and tasks
- Every build step runs in an isolated, reproducible container
- Pluggable resource types implemented as container images rather than server plugins
- Visual pipeline graph UI showing job dependencies and status
- Stateless architecture avoiding drift on shared build agents
- Strong ties to the Cloud Foundry ecosystem and its release engineering