This repository provides two powerful tools for working with Kubernetes Custom Resource Definitions (CRDs):

• generate-crd-api: Generate Go API types from CRD YAML files.
• extract-crd-api: Extract Go API types from existing modules for selected CRDs.

Below you’ll find documentation and usage examples for both tools.

generate-crd-api is used to automatically generate Go API types from one or more Kubernetes CRD YAML files. This simplifies integration testing, code generation, and documentation.

Requires Go 1.24+.

go get -tool github.com/bakito/crd-gen/cmd/generate-crd-api@latest

You can use go generate directives to invoke the tool. Example:

//go:build generate
// +build generate

//go:generate go tool generate-crd-api --target .testdata/ \
    --crd testdata/certificates.cert-manager.io.yaml \
    --crd testdata/certificaterequests.cert-manager.io.yaml \
    --crd testdata/clusterissuers.cert-manager.io.yaml

• --target <dir>: Directory to write generated Go files to.
• --crd <file>: Path to a CRD YAML file. Can be specified multiple times.

extract-crd-api extracts Go API types for CRDs from existing Go modules. It enables you to reuse and synchronize CRD types from upstream or third-party providers.

Requires Go 1.24+.

go get -tool github.com/bakito/crd-gen/cmd/extract-crd-api@latest

Use go generate to invoke the tool and extract API types from modules.

//go:build generate
// +build generate

//go:generate go tool extract-crd-api \
    --module "github.com/upbound/[email protected]" \
    --use-git --clear \
    --path apis/vault/v1alpha1      --target ./apis/vault211/vault      --exclude .*\.managed.go
//go:generate go tool extract-crd-api \
    --module "github.com/upbound/[email protected]" \
    --use-git --clear \
    --path apis/kubernetes/v1alpha1 --target ./apis/vault211/kubernetes --exclude .*\.managed.go

• --module <module@version>: Go module and version to extract API types from.
• --use-git: Use git to fetch the module.
• --clear: Clear the target directory before extraction.
• --path <dir>: Path inside the module to extract API types from.
• --target <dir>: Target directory for extracted files.
• --exclude <pattern>: Regex pattern for files to exclude.