
Flux allows you to declaratively define the deployment state of your Kubernetes environment. Deployements are automated and triggered off of code pushes. Flux is a tool that automatically ensures that the state of a cluster matches your specified configuration in git. It uses an operator in the cluster to trigger deployments inside Kubernetes, which means you don't need a separate CD tool. It monitors all relevant image repositories, detects new images, triggers deployments and updates the desired running configuration based on that (and a configurable policy).
More information can be found at the official Weavworks site and Flux GitHub repository. The following links provide additional documentation on GitOps, Flux.