• Install a specific helm chart:
  • helm install RELEASE_NAME REPOSITORY_NAME --version VERSION -f values.yaml -n NAMESPACE --create-namespace
• List all the versions from a repo:
  • helm search repo REPOSITORY_NAME --versions
  • With exact match: helm search repo --regexp '\vREPOSITORY_NAME\v' --versions
    • \v is used because exact match is not working correctly in helm search: https://github.com/helm/helm/issues/3890
• Delete/Uninstall a helm chart in a cluster:
  • helm uninstall RELEASE_NAME -n NAMESPACE

How helm knows the resources it created

• Helm adds the labels to the resources like:
  • release
  • heritage
    • value is Helm
  • chart
    • Chart name
  • app
• The labels can be fetched by
  • kubectl -n NAMESPACE get RESOURCE_TYPE --show-labels
  • e.g. : kubectl -n default get pods --show-labels

Environment specific values

• helm COMMAND RELEASE_NAME CHART_NAME_OR_DIR -n NAMESPACE -f values.common.yaml -f values.ENVIRONMENT_SLUG.yaml
• Helm will apply from left to right, during the application it will either do the addition or override the values to make the final values object to apply
• Other tools
  • helmfile
  • ocra

Variable and templates

• https://stackoverflow.com/questions/69702163/helm-kube-prometheus-stack-can-i-create-rules-for-exporters-in-values-yaml
• https://stackoverflow.com/questions/59575498/what-is-the-usage-of-include-in-helm

Restart on config map update

• https://stackoverflow.com/questions/58602311/will-helm-upgrade-restart-pods-even-if-they-are-not-affected-by-upgrade

References:

• https://github.com/helm/helm/issues/5257
• https://github.com/helm/helm/blob/ecef026b68a23f0c1399d98425134ce837126831/docs/using_helm.md#customizing-the-chart-before-installing
• https://friedrichkurz.me/blog/2022/06/18/keeping-environment-specific-helm-configuration-dry/