crd2jsonschema

Converts Kubernetes Custom Resource Definitions (CRDs) OpenAPI V3.0 schemas to JSON schema draft 4.

Usage

Usage: crd2jsonschema [options] [crd]...

Convert Kubernetes Custom Resource Definitions (CRDs) OpenAPI V3.0 schemas to
JSON schema draft 4. CRDs can be specified as a file path or as a URL.

Options:
  -o path     Output directory for JSON schema files
  -a          Create all.json which references individual files
  -v          Print the version of crd2jsonschema
  -h          Print this help
  --no-strict Disables the default strict mode which reports unknown properties as errors

Examples:

# convert a single CRD file and print to stdout
crd2jsonschema your-crd.yml

# convert a single CRD from a URL and write as group/kind_version.json to
# output dir
crd2jsonschema -o output-dir https://example.com/your-crd.yml

# convert multiple CRDs, write group/kind_version.json files to output dir and
# create all.json file
crd2jsonschema -a -o ./output your-crd1.yml your-crd2.yml
crd2jsonschema -a -o ./output ./crds/*.yml

Installation

Docker

# convert a single CRD and write to output dir
docker run --rm -v $(pwd):/app ghcr.io/tricktron/crd2jsonschema -o output your-crd.yaml
# convert multiple CRDs, write group/kind_version.json files to output dir and
# create all.json file
docker run --rm -v $(pwd):/app ghcr.io/tricktron/crd2jsonschema -a -o output crds/*.crd.yml

Nix Flakes

Install and run with:

nix profile install github:tricktron/crd2jsonschema
crd2jsonschema -h

or run directly with nix run github:tricktron/crd2jsonschema -- -h

Use Case

Catch errors in Kubernetes manifests early by validating them against the JSON schema before applying them to the cluster. This shortens the feedback loop during development and can be used in CI/CD pipelines to safeguard against invalid manifests.

The generated JSON schemas can be used with the following tools:

• Contribute your schemas to the CRDs-catalog.
• The yaml-language-server which adds autocompletion, validation, diagnostics and hover support for your json schemas.

Credits

• yq to parse YAML files.
• openapi-schema-to-json-schema to convert OpenAPI V3.0 schemas to JSON schema draft 4.