lint-helm-schema.yml

Validate Helm chart values files against a JSON schema using check-jsonschema. Ensures that values.yaml and any additional values files conform to the chart's declared schema.

Inputs

Input	Type	Description	Required	Default
CHART_PATH	string	Path to the Helm chart directory containing the JSON schema	Yes	-
SCHEMA_FILE	string	JSON schema filename relative to CHART_PATH	No	values.schema.json
VALUES_FILES	string	Comma-separated list of values files to validate against the schema, relative to CHART_PATH (e.g., values.yaml,test-values.yaml,values/dev.yaml)	No	values.yaml
RUNS_ON	string	Runner labels as JSON array (e.g., '["ubuntu-24.04"]' or '["self-hosted", "linux"]')	No	["ubuntu-24.04"]

Permissions

Scope	Access	Description
contents	read	Read chart sources

Notes

• Uses check-jsonschema (installed via pip) to validate values files against the chart's JSON schema.
• Fails if the schema file (SCHEMA_FILE) does not exist under CHART_PATH.
• Skips individual values files that are not found (with a warning) rather than failing, unless no files remain to validate.
• Multiple values files can be validated in a single run by providing a comma-separated list in VALUES_FILES.
• Useful to catch values that do not match the expected structure before deploying.

Examples

The examples show validating a chart with a single values file, providing multiple values files for broader schema coverage, and using a custom JSON schema instead of the default values.schema.json.

Simple example

Validates values.yaml against values.schema.json in charts/my-chart. Fails immediately if the schema file does not exist or if any value does not conform to its declared type or constraint.

jobs:
  lint-helm-schema:
    uses: this-is-tobi/github-workflows/.github/workflows/lint-helm-schema.yml@v0
    with:
      CHART_PATH: charts/my-chart

Multiple values files

Validates three values files in a single run — useful for projects with per-environment overrides. Files that are not found are skipped with a warning rather than a hard failure.

jobs:
  lint-helm-schema:
    uses: this-is-tobi/github-workflows/.github/workflows/lint-helm-schema.yml@v0
    with:
      CHART_PATH: charts/my-chart
      VALUES_FILES: "values.yaml,values/dev.yaml,values/prod.yaml"

Custom schema file

Uses custom-schema.json instead of the default values.schema.json. Useful when a non-standard naming convention is in use, or to apply a specific schema to a subset of values files.

jobs:
  lint-helm-schema:
    uses: this-is-tobi/github-workflows/.github/workflows/lint-helm-schema.yml@v0
    with:
      CHART_PATH: charts/my-chart
      SCHEMA_FILE: custom-schema.json
      VALUES_FILES: "values.yaml,ci-values.yaml"