OpenFaaS

OpenFaaS is an open-source framework for building and hosting functions as a service. It enables developers to package individual functions as containers and deploy them behind an HTTP gateway, allowing event-driven and on-demand execution. OpenFaaS runs on Kubernetes and Docker Swarm and can also operate in standalone mode, providing a portable platform for serverless workloads. The project was created by Alex Ellis and released as an open-source project in 2016, growing through community contributions and an expanding ecosystem of templates and tooling.

At its core, OpenFaaS comprises a gateway that routes requests to function containers, function workloads managed by the chosen orchestrator, an optional queue worker for asynchronous invocations, and a templates system used with the faas-cli to build and deploy functions. Developers can write functions in multiple languages supported by templates and deploy new functions with a single command. OpenFaaS includes a web user interface and a command-line interface to manage functions, along with monitoring integrations via Prometheus and Grafana.

Key features include autoscaling and scale-to-zero behavior via the faas-idler component, straightforward deployment pipelines, and language-agnostic function packaging. The framework emphasizes portability, enabling users to move workloads between Kubernetes and Docker Swarm.

OpenFaaS has a broad user base in cloud-native environments and is complemented by related projects such as OpenFaaS Cloud for managed deployment and eventing. It is maintained by a community of contributors and is one of several serverless frameworks referenced within Kubernetes ecosystems.