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Helm

The Helm module validates Helm charts across your workspace. It discovers charts, lints them, and checks that values files render with helm template --dry-run=client — catching structural and templating problems before a PR ever reaches a cluster. Reach for it in any repo that ships Kubernetes applications with Helm, where it makes a strong PR check by validating chart changes before deploy tooling sees them, and it shares one pinned Helm version across the whole workspace.

Official module: dagger/helm

Add it to your workspace​

dagger install github.com/dagger/helm

Run the checks​

dagger check                       # run every check in the workspace
dagger check helm:lint             # lint every discovered chart
dagger check helm:assert-template  # render discovered values files and fail on errors

The module discovers charts by finding every Chart.yaml in the workspace and treats the containing directory as the chart root, so templates, subcharts, CRDs, and files referenced through .Files are all available to Helm. You can see which charts the module finds with charts.

lint runs helm lint against each chart's default values, and once more for each discovered values file. assert-template renders each values file with helm template --dry-run=client and fails if templating breaks; it intentionally skips the bare chart, since some charts only render with one of their explicit values files.

Configure it​

List the current settings and their values with dagger settings helm, then set one with dagger settings helm <key> <value>. Settings are stored in dagger.toml under [modules.helm.settings]:

  • version (default 3.18.4): the Helm version used for lint and template. Pin it so local runs and CI use the same Helm release.
  • valuesGlob (default ci/*-values.yaml): a glob, relative to each chart root, that selects the values files to check. Every matching file becomes a separate scenario in both lint and assert-template. The default follows Helm chart-testing's CI convention, so files like ci/prod-values.yaml are picked up automatically.
dagger settings helm version 3.18.4
dagger settings helm valuesGlob "ci/*-values.yaml"

To check a chart under several configurations, add more values files that match the glob. With the default glob, the chart below is rendered and linted once per file under ci/:

charts/api/
  Chart.yaml
  values.yaml
  ci/
    prod-values.yaml
    minimal-values.yaml

Working with other modules​

Use this module for repos that ship Kubernetes applications with Helm. It is a strong PR check because it validates chart changes before deploy tooling sees them.