Helm umbrella charts, for those who aren’t familiar, describe and encapsulate a deployable collection of loosely couple Kubernetes components as a higher-order Helm chart. In other words, a collection of software elements that each have their own individual charts but, for whatever reason (e.g. design choices, ease of deployability, versioning complexities), must be installed or upgraded as a since atomic unit.

A simple use case for an Umbrella chart could be that of a web application with a separate web-scraper component that populates a database. In this trivial example, the web application and scraper would each be described in their own Helm charts which can be individually deployed. For the purposes of the example, let’s assume that the one application would not start up without the other, and due to some legacy reason, the two cannot be released separately. This is a good use case for an umbrella chart as the umbrella chart would encapsulate both applications into a single deployable unit. Together with Helm command-line flags such as atomic, Helm will ensure that the failure of one component to install or upgrade rolls both back to their previous state.

#helm #k8s #helm-3 #kubernetes