Helm in Practice

Helm Plugins

Helm plugins are extensions that augment the functionality of Helm. They can add new commands, modify existing ones, or integrate with other tools and services. Helm categorizes plugins into three types:

• CLI plugins: These plugins add new commands to the Helm CLI. For example, a plugin might add a command for linting charts or for managing chart repositories.

Example: helm-diff adds a helm diff command that shows the differences between Helm releases. For example, you can use helm diff upgrade my-release stable/postgresql --values values.yaml to see what changes would be applied if you upgraded the my-release release of the PostgreSQL chart with the specified values.

• Getter plugins: These plugins extend Helm's ability to fetch charts or even other plugins from location types not natively supported by Helm. For example, a plugin might allow Helm to fetch charts from a custom storage backend, like an S3 bucket or a private Git repository.

Example: helm-s3 allows you to use an Amazon S3 bucket as a Helm chart repository.

• Post-renderer plugins: These plugins modify the rendered Kubernetes manifests before they are applied to the cluster. For example, a plugin might add additional labels or annotations to all resources or perform custom transformations on the manifests.

Example: helm-secrets allows you to manage secrets in Helm charts using tools like Mozilla SOPS. For example, you can use helm secrets install my-release ./my-chart to install a chart with encrypted secrets that are decrypted on the fly during the installation process.

To install a Helm plugin, you can use the helm plugin install command, followed by the URL of the plugin's repository. For example, to install the helm-diff plugin, you would run:

helm plugin install https://github.com/databus23/helm-diff \
    --verify=false

To list the installed plugins, you can use the helm plugin list command: