Support helm lint

[cgetzen]

None of the yaml linters or kubeval support helm

[nvuillam]

Do you have a helm linter to propose ?

[cgetzen]

https://helm.sh/docs/helm/helm_lint

[nvuillam]

I'm not (yet) familiar with helm, please could you provide:

• example calls for helm lint
• a valid helm file
• an invalid helm file

Thanks !

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[ThomasSanson]

Hello,

I would like to incorporate the "helm lint" feature into megalinter.

@nvuillam Here are some example calls for helm lint:

# Lint a single chart
helm lint mychart

# Lint all charts in a chart directory
helm lint chartdirectory

# Lint a chart and print the output to a file
helm lint mychart > lint-output.txt

A valid Helm chart file might look something like this:

apiVersion: v2
name: mychart
version: 1.0.0

# A chart can contain one or more charts
charts:
  # This is the name of the chart
  - name: myapp
    # The chart version
    version: 1.0.0
    # A chart can contain one or more templates
    templates:
      # The name of the template
      - name: deployment.yaml
        # The template content
        content: |
          apiVersion: apps/v1
          kind: Deployment
          metadata:
            name: myapp-deployment
          spec:
            replicas: 3
            selector:
              matchLabels:
                app: myapp
            template:
              metadata:
                labels:
                  app: myapp
              spec:
                containers:
                  - name: myapp
                    image: myapp:latest
                    ports:
                      - containerPort: 80

An invalid Helm chart file might have a syntax error or be missing required fields, for example:

apiVersion: v2
name: mychart

# A chart is missing the 'version' field

# A chart can contain one or more charts
charts:
  # This is the name of the chart
  - name: myapp
    # The chart version
    version: 1.0.0
    # A chart can contain one or more templates
    templates:
      # The name of the template
      - name: deployment.yaml
        # The template content
        content: |
          apiVersion: apps/v1
          kind: Deployment
          metadata:
            name: myapp-deployment
          spec:
            replicas: 3
            selector:
              matchLabels:
                app: myapp
            template:
              metadata:
                labels:
                  app: myapp
              spec:
                containers:
                  - name: myapp
                    image: myapp:latest
                    ports:
                      - containerPort: 80

I hope this helps! Let me know if you have any other questions.

If you would like, I am willing to try making a pull request to include this new linter.

[nvuillam]

@ThomasSanson that would be great :)

You can start your PR and we'll provide support if necessary :)

Instructions to add a linter: https://megalinter.io/latest/contributing/#add-a-new-linter

Example of recent PR with a new linter, by @bdovaz : #2150 (don't be scared by the number of files, most of them are automatically generated, updates are mainly in descriptor file. I suggest you add helm lint in KUBERNETES descriptor -> https://github.com/oxsecurity/megalinter/blob/main/megalinter/descriptors/kubernetes.megalinter-descriptor.yml )

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Thank you for your contributions.

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[nvuillam]

@ThomasSanson are you still interested in providing a PR ? :)

[ThomasSanson]

@ThomasSanson are you still interested in providing a PR ? :)

@nvuillam Yes, I'm planning to do it this Sunday due to lack of time

[nvuillam]

Great :)

[ThomasSanson]

In progress, I've been sick...

However, I find it challenging to fully comprehend what actions I need to take to make a meaningful contribution. Despite this, I am committed to doing my best.