Add support for multiple executor backends. Create Executor interface and allow executors to register themselves with the application. Update README (Todo list).

executors/abstract.go

@@ -0,0 +1,47 @@
+package executors
+
+import (
+	"fmt"
+)
+
+type Job struct {
+	Command       []string
+	Args          []string
+}
+
+type Executor interface {
+	Start() error
+	Stop() error
+	WaitForState(ExecutorPhase) error
+	String() string
+}
+
+type AbstractExecutor struct {
+	Job        Job
+}
+
+type ExecutorPhase string
+
+const (
+	ExecutorPreparing    ExecutorPhase = "Preparing"
+	ExecutorRunning      ExecutorPhase = "Running"
+	ExecutorSucceeded    ExecutorPhase = "Succeeded"
+	ExecutorFailed       ExecutorPhase = "Failed"
+	ExecutorUnknown      ExecutorPhase = "Unknown"
+)
+
+func (e *AbstractExecutor) Start() error {
+	return nil
+}
+
+func (e *AbstractExecutor) Stop() error {
+	return nil
+}
+
+func (e *AbstractExecutor) WaitForState(p ExecutorPhase) error {
+	return nil
+}
+
+func (e *AbstractExecutor) String() string {
+	return fmt.Sprintf("%s %s", e.Job.Command, e.Job.Args)
+}

executors/kubernetes/kubernetes_executor.go

@@ -0,0 +1,133 @@
+package kubernetes
+
+import (
+	"time"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/client"
+
+	log "github.com/Sirupsen/logrus"
+
+	"github.com/munnerz/plex-elastic-transcoder/executors"
+	"github.com/munnerz/plex-elastic-transcoder/common"
+)
+
+const podBasename = "plex-transcoder"
+const kubernetesHost = "10.20.40.254:8080"
+const kubernetesNamespace = "plex"
+const dockerImage = "registry.marley.xyz/e720/plex-new-transcoder"
+
+type KubernetesExecutor struct {
+	executors.AbstractExecutor
+
+	Host       string
+	Namespace  string
+	Image      string
+
+	pod        *api.Pod
+	client     *client.Client
+}
+
+func (e *KubernetesExecutor) createPod() *api.Pod {
+	return &api.Pod{
+				TypeMeta: api.TypeMeta{
+					Kind: "Pod",
+				},
+				ObjectMeta: api.ObjectMeta{
+					GenerateName: podBasename,
+					Namespace: e.Namespace,
+				},
+				Spec: api.PodSpec{
+					RestartPolicy: api.RestartPolicyNever,
+					Containers: []api.Container{
+						api.Container{
+							Name: podBasename,
+							Image: e.Image,
+							Command: e.Job.Command,
+							Args: e.Job.Args,
+						},
+					},
+				},
+			}
+}
+
+func (e *KubernetesExecutor) Start() error {
+	log.Print("Executing job: ", e)
+
+	e.pod = e.createPod()
+
+	client, err := client.New(
+		&client.Config{
+			Host: e.Host,
+		})
+
+	if err != nil {
+		return err
+	}
+
+	e.client = client
+
+	log.Print("Creating pod...")
+	pod, err := e.client.Pods(e.pod.ObjectMeta.Namespace).Create(e.pod)
+
+	if err != nil {
+		return err
+	}
+
+	e.pod = pod
+
+	log.Print("Successfully scheduled job on cluster with name: ", e.pod.ObjectMeta.Name)
+
+	return nil
+}
+
+func (e *KubernetesExecutor) Stop() error {
+	return e.client.Pods(e.pod.ObjectMeta.Namespace).Delete(e.pod.ObjectMeta.Name, nil)
+}
+
+func podPhaseToExecutorPhase(in api.PodPhase) executors.ExecutorPhase {
+	switch in {
+	case api.PodRunning:
+		return executors.ExecutorRunning
+	case api.PodPending:
+		return executors.ExecutorPreparing
+	case api.PodSucceeded:
+		return executors.ExecutorSucceeded
+	case api.PodFailed:
+		return executors.ExecutorFailed
+	default:
+		return executors.ExecutorUnknown
+	}
+}
+
+func (e *KubernetesExecutor) WaitForState(targetState executors.ExecutorPhase) error {
+	Loop:
+	for {
+		pod, err := e.client.Pods(e.pod.ObjectMeta.Namespace).Get(e.pod.ObjectMeta.Name)
+		if err != nil {
+			return err
+		}
+
+		Switch:
+		switch podPhaseToExecutorPhase(pod.Status.Phase) {
+		case targetState:
+			break Loop
+		default:
+			break Switch
+		}
+		time.Sleep(1 * time.Second)
+	}
+	return nil
+}
+
+func init() {
+	common.RegisterExecutor("kubernetes", common.ExecutorFactory{
+		Create: func(j executors.Job) executors.Executor {
+			return &KubernetesExecutor{
+				Host: kubernetesHost,
+				Namespace: kubernetesNamespace,
+				Image: dockerImage,
+			}
+		},
+	})
+}