Dependencies and Subcharts

Part of the Helm course

Almost nothing you deploy actually stands alone. A web service usually wants a cache sitting next to it. A worker wants a queue. An API wants a database, or at least a connection string pointing at one. You could write your own Deployment, Service, and PVC for Redis by hand and paste them into your chart, but Redis's real chart already handles the failover modes, the persistence options, and the security settings...

A subchart is a chart that another chart (the parent chart) pulls in and installs alongside its own resources, as one release. You declare one by adding a dependencies: block to the parent's Chart.yaml ...