The serverless architecture has popularized a FaaS style of programming among developers; it helps developers focus on solving core business problems with independently built and deployed functions that react to an event, run a business process, produce other events in the process and scale down to zero. Historically, proprietary serverless platforms such as AWS Lambda or Microsoft Azure Functions have enabled this programming paradigm. Knative is an open-source Kubernetes-based platform to run FaaS workloads. There are few things that stand out about Knative: it's open source and provider agnostic; it implements the serverless workflow as described in the CNCF Serverless Working Group whitepaper; it ensures cross-service interoperability by implementing its eventing interface consistent with CNCF CloudEvents specification; and, most importantly, it addresses a common challenge of operating a harmonized and yet hybrid FaaS and long-running container-based architecture. It easily integrates with both Istio and Kubernetes. For example, developers can take advantage of roll-out strategies that Istio implements by traffic splitting between different revisions of the functions. Developers can take benefit of Istio-provided observability not only for long-running container services but also for FaaS programs in the same Kubernetes environment. We anticipate that Knative open-source eventing interface will continue to enable new underlying source and destination event integrations.
As application developers, we love to focus on solving core business problems and let the underlying platform handle the boring but difficult tasks of deploying, scaling and managing applications. Although serverless architecture is a step in that direction, most of the popular offerings are tied to a proprietary implementation, which means vendor lock-in. Knative tries to address this by being an open source serverless platform that integrates well with the popular Kubernetes ecosystem. With Knative you can model computations on request in a supported framework of your choice (including Ruby on Rails, Django and Spring among others); subscribe, deliver and manage events; integrate with familiar CI and CD tools; and build containers from source. By providing a set of middleware components for building source-centric and container-based applications that can be elastically scaled, Knative is an attractive platform that deserves to be assessed for your serverless needs.
