Override Helm values at install time

WHAT THIS TESTS Whether you know that charts are parameterized through values and how to override those values without modifying the chart itself.

A GOOD ANSWER COVERS Helm exposes configuration through values. The chart ships defaults in values.yaml, and you override them at install time in two main ways. Use -f or --values to point at one or more custom YAML files, which is the preferred approach for many or environment-specific settings: helm install myapp ./chart -f prod-values.yaml. Use --set for a few ad hoc overrides on the command line: helm install myapp ./chart --set image.tag=v2.1 --set replicaCount=3. You can combine them. Precedence matters: the chart's default values.yaml is the base, each -f file overrides earlier ones in the order given, and --set takes highest priority, overriding files. There is also --set-string for forcing string types and --set-file to read a value from a file. The templates reference these as .Values.image.tag and so on.

COMMON WRONG ANSWERS Editing the chart's templates or its bundled values.yaml directly, which breaks reuse and upgrades; forgetting precedence order; or thinking you must fork the chart to change a replica count.

LIKELY FOLLOW-UPS What is the precedence between multiple -f files and --set? When use --set-string? How do you inspect the final rendered values?

ONE CONCRETE EXAMPLE For production you run helm install api ./chart -f values-prod.yaml --set image.tag=1.4.2. The prod file sets replicaCount to 10 and resource limits, while --set pins the exact image tag from your build pipeline. The chart templates pick these up via .Values, and you can verify with helm get values api or helm template.