Helm Charts

Helm exists to solve one problem: the same application needs slightly different manifests in dev, staging, and prod, and copy-pasting YAML across environments guarantees drift. A chart is a template plus a values contract — the moment the templates start encoding environment-specific logic instead of taking it as input, the chart has stopped doing its job.

The values file is the API of the chart; everyone who consumes it, including future-you, should be able to configure the workload without reading the templates. A chart is good if you can predict its rendered output from values.yaml alone.

1. Design values.yaml as a contract, not a dump

Every value you expose is something a consumer now depends on — expose too little and people fork the chart to add one setting; expose too much and every value becomes load-bearing forever. The right test: does this need to vary by environment or by deployer? If not, it's a template default, not a value.