This repository aggregates hundreds of popular Kubernetes CRDs (CustomResourceDefinition) in JSON schema format. These schemas can be used by various tools such as Datree, Kubeconform and Kubeval, as an alternative to kubectl --dry-run, to perform validation on custom (and native) Kubernetes resources.

Running Kubernetes schema validation checks helps apply the "shift-left approach" on machines without giving them access to your cluster (e.g. locally or on CI).

Furthermore, using the Red Hat YAML plugin for VS Code you are able to get intellisense and validation for CRDs.

👉 If you encounter custom resources that are not part of the catalog, or you want to validate the schemas in an air-gapped environment, use the CRD Extractor.

datree test [MANIFEST]

kubeconform -schema-location default -schema-location 'https://raw.githubusercontent.com/datreeio/CRDs-catalog/main/{{.Group}}/{{.ResourceKind}}_{{.ResourceAPIVersion}}.json' [MANIFEST]

Only supported with the CRD Extractor

This mini-guide assumes that you already have the VS Code editor installed along with the Red Hat YAML plugin.

The basic idea is that you can annotate your YAML files with a $schema property that points to the relevant validation schema. The Red Hat YAML plugin will then use this schema to provide intellisense and validate your YAML files. You can have multiple schema annotations in your files if you have multiple resources in the same file.

The base URL for the schemas is: https://raw.githubusercontent.com/datreeio/CRDs-catalog/main/.

Example:

---
# yaml-language-server: $schema=https://datreeio.github.io/CRDs-catalog/cilium.io/ciliumnetworkpolicy_v2.json
apiVersion: cilium.io/v2
kind: CiliumNetworkPolicy
[...]
---
# yaml-language-server: $schema=https://datreeio.github.io/CRDs-catalog/cilium.io/ciliumegressgatewaypolicy_v2.json
apiVersion: cilium.io/v2
kind: CiliumEgressGatewayPolicy
[...]

To help annotating your YAML documents, you can use the annotate-yaml utility script. This script will automatically add the $schema property to your YAML documents based on the CRD(s) you are using.

This repository also contains a handy utility that extracts all CRDs from a cluster and converts them to JSON schema.

1. Checks that the prerequisites are installed.
2. Extracts your CRDs from your cluster using kubectl.
3. Using the script from openapi2jsonschema.py from kubeconform to convert your CRDs from openAPI to JSON schema.

This utility supports MacOS and Linux.

The following programs are required to be installed on the machine running this utility:

• python3
• kubectl

To use the CRD Extractor:

1. Download the latest release from this repository.
2. Extract, and run the utility:

./crd-extractor.sh

If the catalog is missing public custom resources (CRs) that you would like to automatically validate using these tools, you can open an issue or use the CRD Extractor to add the schemas to this repository by creating a pull request.

• opensource.com - Why you need to use Kubernetes schema validation tools
• redhat.com - Validating OpenShift Manifests in a GitOps World
• kubeval/issues/47 - cannot validate CustomResourceDefinitions