Show HN: Update your CRDs with confidence ( schema validation with cty) (github.com)

Hello everyone!

Previously I wrote about cty[^1] that can be used to generate valid YAML samples from a CRD ( now, including things like, valid Pattern generated random string, enums, default values, minimum int, minimum number of items.. etc ).

It also has a website that can be used to achieve the same thing here: https://crdtoyaml.com/

This update https://github.com/Skarlso/crd-to-sample-yaml/releases/tag/v... brings a feature with it, which I think is super cool. If not, well, then no. :)

Basically, inspired by `helm unittest` the user can define a test like this:

    suite: test aws clusters infrastructure crds
    template: sample-tests/crds/infrastructure.cluster.x-k8s.io_awsclusters.yaml
    tests:
      - it: matches AWSCluster crds correctly
        asserts:
          - matchSnapshot:
              # this will generate one snapshot / CRD version and match all of them to the right version of the CRD
              path: sample-tests/__snapshots__
          - matchSnapshot:
              path: sample-tests/__snapshots__
              # generates a yaml file
              minimal: true
          - matchString:
              apiVersion: infrastructure.cluster.x-k8s.io/v1beta2
              kind: AWSCluster
              spec:
                controlPlaneEndpoint:
                  host: string
                  port: 1
          - matchString:
              apiVersion: infrastructure.cluster.x-k8s.io/v1beta2
              kind: AWSCluster
              spec:
                controlPlaneEndpoint:
                  # this is failing the test because the type is number and not string
                  host: 12345
                  port: 1

This will take a CRD and test the CRD validates a given sample. In this case, it's a string and two snapshot values. The snapshots can be generated using `cty test sample-tests --update`.

The snapshots will contain valid values, such as minimum integer, minimum number of items, defaults, enums, Patterns ( yes it generates random value that will satisfy a given pattern regex ) and more.

It will only ever match the right version with the right version. Meaning it won't try `v1beta2` to match to `v1alpha1`. Since CRD files can have multiple versions in them.

It can be added as a simple make target like helm unittest.

This is very much an alpha feature, so please, if you do use it, report any problems. :)

Thank you! Enjoy.

[^1]: https://github.com/Skarlso/crd-to-sample-yaml