Generate YAML manifest from Kubernetes types

I'm looking into writing a tool that generates Kubernetes definitions programatically for our project.

I've found that the API types in Kubernetes can be found in k8s.io/kubernetes/pkg/api. I would like to output YAML based on these types.

Given an object like this:

ns := &api.Namespace{
    ObjectMeta: api.ObjectMeta{
        Name: "test",
    },
}

What's the best way to generate the YAML output expected by kubectl create?

Found it, for future reference, here's what you might want to do:

package main

import (
	"os"

	"k8s.io/kubernetes/pkg/api/unversioned"
	"k8s.io/kubernetes/pkg/api/v1"
	"k8s.io/kubernetes/pkg/runtime/serializer/json"
)

func main() {
	ns := &v1.Namespace{
		TypeMeta: unversioned.TypeMeta{
			Kind:       "Namespace",
			APIVersion: "v1",
		},

		ObjectMeta: v1.ObjectMeta{
			Name: "test",
		},
	}

	e := json.NewYAMLSerializer(json.DefaultMetaFactory, nil, nil)

	err := e.EncodeToStream(ns, os.Stdout)
	if err != nil {
		panic(err)
	}
}

This might not be the best practice (better suggestions welcome), but it does the job.

Their API has updated, so this is how it looks like:

import k8sJson "k8s.io/apimachinery/pkg/runtime/serializer/json"
...
serializer := k8sJson.NewSerializerWithOptions(
	k8sJson.DefaultMetaFactory, nil, nil,
	k8sJson.SerializerOptions{
		Yaml:   true,
		Pretty: true,
		Strict: true,
	},
)

package main

import (
	"os"

	v1 "k8s.io/api/core/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
	"k8s.io/apimachinery/pkg/runtime/serializer/json"
)

func main() {
	ns := &v1.Namespace{
		TypeMeta: metav1.TypeMeta{
			Kind:       "Namespace",
			APIVersion: "v1",
		},

		ObjectMeta: metav1.ObjectMeta{
			Name: "test",
		},
	}

	e := json.NewYAMLSerializer(json.DefaultMetaFactory, nil, nil)

	//err := e.EncodeToStream(ns, os.Stdout)
	err := e.Encode(ns, os.Stdout)
	if err != nil {
		panic(err)
	}
}