kubeval: Simple Example #

Overview #

This example demonstrates how to declaratively run kubeval function to validate KRM resources.

Fetch the example package #

Get the example package by running the following commands:

$ kpt pkg get https://github.com/kptdev/krm-functions-catalog.git/examples/kubeval-simple

The following is the Kptfile in this example:

apiVersion: kpt.dev/v1
kind: Kptfile
metadata:
  name: example
pipeline:
  validators:
    - image: ghcr.io/kptdev/krm-functions-catalog/kubeval:latest
      configMap:
        strict: 'true'

The function configuration is provided using a ConfigMap. We set 2 key-value pairs:

strict: 'true': We disallow unknown fields.
skip_kinds: MyCustom: We skip resources of kind MyCustom.

Function invocation #

Try it out by running the following commands:

$ kpt fn render kubeval-simple --results-dir /tmp

Expected Results #

Let’s take a look at the structured results in /tmp/results.yaml:

apiVersion: kpt.dev/v1
kind: FunctionResultList
metadata:
  name: fnresults
exitCode: 1
items:
  - image: ghcr.io/kptdev/krm-functions-catalog/kubeval:latest
    exitCode: 1
    results:
      - message: Additional property templates is not allowed
        severity: error
        resourceRef:
          apiVersion: v1
          kind: ReplicationController
          name: bob
        field:
          path: templates
        file:
          path: resources.yaml
      - message: 'Invalid type. Expected: [integer,null], given: string'
        severity: error
        resourceRef:
          apiVersion: v1
          kind: ReplicationController
          name: bob
        field:
          path: spec.replicas
        file:
          path: resources.yaml

There are validation error in the resources.yaml file, to fix them:

replace the value of spec.replicas with an integer
change templates to template

Rerun the command, and it should succeed now.