Config generation

config_gen.go

package main

import (
	"fmt"
	"os"

	"k8s.io/client-go/1.4/pkg/api/unversioned"
	"k8s.io/client-go/1.4/pkg/api/v1"
	"k8s.io/client-go/1.4/pkg/apis/extensions/v1beta1"
	"k8s.io/client-go/1.4/pkg/runtime"
	"k8s.io/client-go/1.4/pkg/runtime/serializer/json"
	"k8s.io/client-go/1.4/pkg/util/intstr"
)

const (
	FlowerTier    string = "flower"
	WebServerTier string = "webserver"
	SchedulerTier string = "scheduler"
	WorkerTier    string = "worker"

	DockerImage string = "gcr.io/all-the-codes/docker_airflow:0.2"
	Airflow     string = "airflow"

	HttpPort            = 80
	WebContainerPort    = 8000
	FlowerContainerPort = 5555
)

func LoadBalancer(tier string, fromPort int32, toPort int, selector map[string]string) *v1.Service {
	result := &v1.Service{
		Spec: v1.ServiceSpec{
			Type: "LoadBalancer",
			Ports: []v1.ServicePort{{
				Protocol:   "TCP",
				Port:       fromPort,
				TargetPort: intstr.FromInt(toPort),
			}},
			Selector: selector},
		ObjectMeta: v1.ObjectMeta{
			Name: tier,
			Labels: map[string]string{
				"app": tier}},
		TypeMeta: unversioned.TypeMeta{
			Kind:       "Service",
			APIVersion: "v1"},
	}
	return result
}

func AirflowContainer(tier string, exposedPorts []int32) v1.Container {
	var ports = []v1.ContainerPort{}
	for _, port := range exposedPorts {
		ports = append(ports, v1.ContainerPort{
			ContainerPort: port})
	}

	return v1.Container{
		Name:            tier,
		Image:           DockerImage,
		ImagePullPolicy: v1.PullAlways,
		Env: []v1.EnvVar{
			v1.EnvVar{
				Name:  "FLOWER_PORT",
				Value: "5555"},
			v1.EnvVar{
				Name:  "AIRFLOW_HOME",
				Value: "/usr/local/airflow"}},
		Ports: ports,
		Args:  []string{tier}}
}

func AirflowDeployment(tier string, exposedPorts ...int32) *v1beta1.Deployment {
	return &v1beta1.Deployment{
		ObjectMeta: v1.ObjectMeta{Name: tier},
		Spec: v1beta1.DeploymentSpec{
			Template: v1.PodTemplateSpec{
				Spec: v1.PodSpec{
					RestartPolicy: v1.RestartPolicyAlways,
					Containers: []v1.Container{
						AirflowContainer(tier, exposedPorts)}},
				ObjectMeta: v1.ObjectMeta{
					Name: tier,
					Labels: map[string]string{
						"app":  Airflow,
						"tier": tier}}}},
		TypeMeta: unversioned.TypeMeta{
			Kind:       "Deployment",
			APIVersion: "extensions/v1beta1"}}
}

func main() {
	objects := []runtime.Object{
		AirflowDeployment(WebServerTier, WebContainerPort),
		AirflowDeployment(FlowerTier, FlowerContainerPort),
		AirflowDeployment(SchedulerTier),
		AirflowDeployment(WorkerTier),
		LoadBalancer(WebServerTier, HttpPort, WebContainerPort,
			map[string]string{"app": Airflow,
				"tier": WebServerTier}),
		LoadBalancer(FlowerTier, HttpPort, FlowerContainerPort,
			map[string]string{
				"app":  Airflow,
				"tier": FlowerTier})}

	e := json.NewYAMLSerializer(json.DefaultMetaFactory, nil, nil)
	for _, object := range objects {
		err := e.Encode(object, os.Stdout)
		if err != nil {
			panic(err)
		}
		fmt.Println("---")
	}
}