ksonnet-gen takes the OpenAPI Kubernetes specification and generates a Jsonnet file representing that API definition.

dep ensure      # Fetch dependencies
go build -o ksonnet-gen .

ksonnet-gen [path to k8s OpenAPI swagger.json] [output dir]

Typically the swagger spec is in something like k8s.io/kubernetes/api/openapi-spec, where k8s.io is in your Go src folder.