From dcd6f8e056a0431db7fd0a40c7a3d4a4549788e8 Mon Sep 17 00:00:00 2001
From: Chris Lu <chris.lu@gmail.com>
Date: Wed, 14 Oct 2020 21:29:18 -0700
Subject: [PATCH] master controller

---
 controllers/master_controller.go | 134 ++++++++++++++++++++++++++++++-
 1 file changed, 131 insertions(+), 3 deletions(-)

diff --git a/controllers/master_controller.go b/controllers/master_controller.go
index 6f9cd52..2492de4 100644
--- a/controllers/master_controller.go
+++ b/controllers/master_controller.go
@@ -17,7 +17,13 @@ limitations under the License.
 package controllers
 
 import (
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
 	"context"
+	"k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"reflect"
 
 	"github.com/go-logr/logr"
 	"k8s.io/apimachinery/pkg/runtime"
@@ -38,14 +44,136 @@ type MasterReconciler struct {
 // +kubebuilder:rbac:groups=seaweed.seaweedfs.com,resources=masters/status,verbs=get;update;patch
 
 func (r *MasterReconciler) Reconcile(req ctrl.Request) (ctrl.Result, error) {
-	_ = context.Background()
-	_ = r.Log.WithValues("master", req.NamespacedName)
+	ctx := context.Background()
+	log := r.Log.WithValues("master", req.NamespacedName)
 
-	// your logic here
+	// Fetch the Master instance
+	master := &seaweedv1.Master{}
+	err := r.Get(ctx, req.NamespacedName, master)
+	if err != nil {
+		if errors.IsNotFound(err) {
+			// Request object not found, could have been deleted after reconcile request.
+			// Owned objects are automatically garbage collected. For additional cleanup logic use finalizers.
+			// Return and don't requeue
+			log.Info("Master resource not found. Ignoring since object must be deleted")
+			return ctrl.Result{}, nil
+		}
+		// Error reading the object - requeue the request.
+		log.Error(err, "Failed to get Master")
+		return ctrl.Result{}, err
+	}
+
+	// Check if the deployment already exists, if not create a new one
+	found := &appsv1.Deployment{}
+	err = r.Get(ctx, types.NamespacedName{Name: master.Name, Namespace: master.Namespace}, found)
+	if err != nil && errors.IsNotFound(err) {
+		// Define a new deployment
+		dep := r.deploymentForMaster(master)
+		log.Info("Creating a new Deployment", "Deployment.Namespace", dep.Namespace, "Deployment.Name", dep.Name)
+		err = r.Create(ctx, dep)
+		if err != nil {
+			log.Error(err, "Failed to create new Deployment", "Deployment.Namespace", dep.Namespace, "Deployment.Name", dep.Name)
+			return ctrl.Result{}, err
+		}
+		// Deployment created successfully - return and requeue
+		return ctrl.Result{Requeue: true}, nil
+	} else if err != nil {
+		log.Error(err, "Failed to get Deployment")
+		return ctrl.Result{}, err
+	}
+
+	// Ensure the deployment size is the same as the spec
+	size := master.Spec.Size
+	if *found.Spec.Replicas != size {
+		found.Spec.Replicas = &size
+		err = r.Update(ctx, found)
+		if err != nil {
+			log.Error(err, "Failed to update Deployment", "Deployment.Namespace", found.Namespace, "Deployment.Name", found.Name)
+			return ctrl.Result{}, err
+		}
+		// Spec updated - return and requeue
+		return ctrl.Result{Requeue: true}, nil
+	}
+
+	// Update the Master status with the pod names
+	// List the pods for this master's deployment
+	podList := &corev1.PodList{}
+	listOpts := []client.ListOption{
+		client.InNamespace(master.Namespace),
+		client.MatchingLabels(labelsForMaster(master.Name)),
+	}
+	if err = r.List(ctx, podList, listOpts...); err != nil {
+		log.Error(err, "Failed to list pods", "Master.Namespace", master.Namespace, "Master.Name", master.Name)
+		return ctrl.Result{}, err
+	}
+	podNames := getPodNames(podList.Items)
+
+	// Update status.Nodes if needed
+	if !reflect.DeepEqual(podNames, master.Status.Nodes) {
+		master.Status.Nodes = podNames
+		err := r.Status().Update(ctx, master)
+		if err != nil {
+			log.Error(err, "Failed to update Master status")
+			return ctrl.Result{}, err
+		}
+	}
 
 	return ctrl.Result{}, nil
 }
 
+// deploymentForMaster returns a master Deployment object
+func (r *MasterReconciler) deploymentForMaster(m *seaweedv1.Master) *appsv1.Deployment {
+	ls := labelsForMaster(m.Name)
+	replicas := m.Spec.Size
+
+	dep := &appsv1.Deployment{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      m.Name,
+			Namespace: m.Namespace,
+		},
+		Spec: appsv1.DeploymentSpec{
+			Replicas: &replicas,
+			Selector: &metav1.LabelSelector{
+				MatchLabels: ls,
+			},
+			Template: corev1.PodTemplateSpec{
+				ObjectMeta: metav1.ObjectMeta{
+					Labels: ls,
+				},
+				Spec: corev1.PodSpec{
+					Containers: []corev1.Container{{
+						Image:   "Master:1.4.36-alpine",
+						Name:    "Master",
+						Command: []string{"Master", "-m=64", "-o", "modern", "-v"},
+						Ports: []corev1.ContainerPort{{
+							ContainerPort: 11211,
+							Name:          "Master",
+						}},
+					}},
+				},
+			},
+		},
+	}
+	// Set Master instance as the owner and controller
+	ctrl.SetControllerReference(m, dep, r.Scheme)
+	return dep
+}
+
+// labelsForMaster returns the labels for selecting the resources
+// belonging to the given Master CR name.
+func labelsForMaster(name string) map[string]string {
+	return map[string]string{"app": "Master", "Master_cr": name}
+}
+
+// getPodNames returns the pod names of the array of pods passed in
+func getPodNames(pods []corev1.Pod) []string {
+	var podNames []string
+	for _, pod := range pods {
+		podNames = append(podNames, pod.Name)
+	}
+	return podNames
+}
+
 func (r *MasterReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	return ctrl.NewControllerManagedBy(mgr).
 		For(&seaweedv1.Master{}).