Values Files and Overrides

Layers of configuration

Every chart ships a values.yaml with defaults. You override them when installing or upgrading, and Helm merges the layers in a fixed order, later layers winning: the chart's own values.yaml, then a parent chart's values for its subcharts, then each file passed with -f / --values in the order given, then --set, --set-string and --set-file flags. Maps are merged key by key, but lists are replaced entirely, not merged. --set uses a compact path syntax (image.tag=2.7.1, ingress.hosts[0].host=shop.example.com) that becomes awkward for anything complex, so keep real configuration in version-controlled values files and use --set mainly for values computed in a pipeline, such as an image tag. helm get values RELEASE shows the values you supplied; add --all to see the fully computed result.

Values precedence

Defaults sit at the bottom; each layer above overrides the ones below it.

Layered values for production

values-prod.yaml overrides values.yaml, and the pipeline sets only the image tag.

# values.yaml (chart defaults)
replicaCount: 1
image:
  repository: registry.example.com/shop-api
  tag: ""            # defaults to the chart's appVersion in templates
resources:
  requests: { cpu: 100m, memory: 128Mi }

# values-prod.yaml (environment overrides)
replicaCount: 3
resources:
  requests: { cpu: 500m, memory: 512Mi }
  limits:   { memory: 1Gi }

# command used by the pipeline
# helm upgrade --install shop-api ./charts/shop-api -n shop \
#   -f values-prod.yaml --set image.tag=2.7.1

Lists do not merge

If the defaults contain tolerations: [a, b] and your file sets tolerations: [c], the result is just [c]. Copy every list entry you want to keep into the override.

Quick check: A value is set in values.yaml, in values-prod.yaml passed with -f, and with --set. Which wins?

• values.yaml
• values-prod.yaml
• The --set value
• Whichever is alphabetically first