Merge pull request #45 from kotaicode/generic-monitors

Generic monitors

clients/clients.go

@@ -37,6 +37,10 @@ type CloudResource interface {
 	Status() (ResourceStatus, error)
 }
 
+type ResourceMonitor interface {
+	GetNewResources(clusterResources map[string]bool) ([]string, error)
+}
+
 var kubeconfig string
 
 func init() {
@@ -68,6 +72,21 @@ func ResourceFactory(resType, tag string) (CloudResource, error) {
 	return resource, nil
 }
 
+// MonitorFactory generates structs that abide by the ResourceMonitor interface.
+// The returned struct can get new resources of the specified type. Each new integration needso to be added to this factory function.
+func MonitorFactory(monitorType string) (ResourceMonitor, error) {
+	var resourceMonitor ResourceMonitor
+
+	switch monitorType {
+	case TypeEC2:
+		resourceMonitor = &EC2Monitor{Type: monitorType}
+	default:
+		return nil, errors.New("Monitor type not found")
+	}
+
+	return resourceMonitor, nil
+}
+
 // GetClient returns a ready to use kubernetes client.
 func GetClient() (client.Client, error) {
 	var err error

clients/ec2.go

@@ -21,6 +21,10 @@ const (
 	resourceMonitorTagKey string = "resource-booking/managed"
 )
 
+type EC2Monitor struct {
+	Type string
+}
+
 // Resource represents a collection of EC2 instances grouped by a common "resource-booking/application" tag.
 type EC2Resource struct {
 	NameTag string
@@ -124,11 +128,22 @@ func (r *EC2Resource) getInstanceIds(nameTag string) ([]*string, error) {
 	return instanceIds, nil
 }
 
-// GetUniqueTags returns a slice of unique tags.
-// It makes a call through the EC2 client to get all the unique tags in the cluster.
-func GetUniqueTags() ([]string, error) {
-	var uniqueTags []string
+// GetNewResources compares the local cluster resources with the ones returned from EC2
+// and gives back a list of resources that need to be created on the cluster.
+func (m *EC2Monitor) GetNewResources(clusterResources map[string]bool) ([]string, error) {
+	uniqueTags, err := GetUniqueTags()
+	if err != nil {
+		return nil, err
+	}
+
+	slice1, slice2 := setDiff(uniqueTags, clusterResources), setDiff(clusterResources, uniqueTags)
+	nonMatchingTags := append(slice1, slice2...)
 
+	return nonMatchingTags, nil
+}
+
+// GetUniqueTags makes a call through the EC2 client to collect all instance tags and returns a set of them
+func GetUniqueTags() (map[string]bool, error) {
 	// Prepare filters
 	tagKey := "tag:" + resourceMonitorTagKey
 	tagValue := "true"
@@ -156,9 +171,16 @@ func GetUniqueTags() ([]string, error) {
 		}
 	}
 
-	for tag := range tagMap {
-		uniqueTags = append(uniqueTags, tag)
-	}
-	return uniqueTags, nil
+	return tagMap, nil
+}
 
+// setDiff returns the difference between two sets
+func setDiff(m1, m2 map[string]bool) []string {
+	slice := make([]string, 0, len(m1))
+	for k := range m1 {
+		if _, ok := m2[k]; !ok {
+			slice = append(slice, k)
+		}
+	}
+	return slice
 }

controllers/resourcemonitor_controller.go

@@ -35,31 +35,6 @@ type ResourceMonitorReconciler struct {
 	Scheme *runtime.Scheme
 }
 
-const (
-	ResourceType      = "ec2"
-	ResourceNamespace = "default"
-)
-
-// sliceToMap returns map, used to convert slice to map
-func sliceToMap(slice []string) map[string]bool { //TODO: give a better name
-	m := make(map[string]bool)
-	for _, s := range slice {
-		m[s] = true
-	}
-	return m
-}
-
-// diff returns a slice of strings, used to compare two maps.
-func diff(m1, m2 map[string]bool) []string { //TODO: give a better name
-	slice := make([]string, 0, len(m1))
-	for k := range m1 {
-		if _, ok := m2[k]; !ok {
-			slice = append(slice, k)
-		}
-	}
-	return slice
-}
-
 //+kubebuilder:rbac:groups=manager.kotaico.de,resources=resourcemonitors,verbs=get;list;watch;create;update;patch;delete
 //+kubebuilder:rbac:groups=manager.kotaico.de,resources=resourcemonitors/status,verbs=get;update;patch
 //+kubebuilder:rbac:groups=manager.kotaico.de,resources=resourcemonitors/finalizers,verbs=update
@@ -71,7 +46,7 @@ func diff(m1, m2 map[string]bool) []string { //TODO: give a better name
 // - https://pkg.go.dev/sigs.k8s.io/[email protected]/pkg/reconcile
 func (r *ResourceMonitorReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
 	log := log.FromContext(ctx)
-	var clusterResources []string
+	clusterResources := make(map[string]bool)
 
 	log.Info("Reconcile resource monitor")
 
@@ -88,34 +63,31 @@ func (r *ResourceMonitorReconciler) Reconcile(ctx context.Context, req ctrl.Requ
 	}
 
 	for _, rs := range resources.Items {
-		clusterResources = append(clusterResources, rs.Spec.Tag)
+		clusterResources[rs.Spec.Tag] = true
 	}
 
-	uniqueTags, err := clients.GetUniqueTags()
+	monitor, err := clients.MonitorFactory(resourceMonitor.Spec.Type)
 	if err != nil {
-		log.Error(err, "Error getting unique tags")
+		log.Error(err, err.Error())
+		return ctrl.Result{}, client.IgnoreNotFound(err)
 	}
-	uniqueTagsMap := sliceToMap(uniqueTags)
-	clusterResourcesMap := sliceToMap(clusterResources)
 
-	slice1 := diff(uniqueTagsMap, clusterResourcesMap) //TODO: give a better name
-	slice2 := diff(clusterResourcesMap, uniqueTagsMap) //TODO: give a better name
-	nonMatchingTags := append(slice1, slice2...)
+	nonMatchingTags, err := monitor.GetNewResources(clusterResources)
+	if err != nil {
+		log.Error(err, err.Error())
+		return ctrl.Result{}, client.IgnoreNotFound(err)
+	}
 
 	for _, tag := range nonMatchingTags {
 		resource := &managerv1.Resource{
-			TypeMeta: metav1.TypeMeta{
-				APIVersion: "manager.kotaico.de/v1",
-				Kind:       "Resource",
-			},
 			ObjectMeta: metav1.ObjectMeta{
 				Name:      tag,
-				Namespace: ResourceNamespace,
+				Namespace: resourceMonitor.Namespace,
 			},
 			Spec: managerv1.ResourceSpec{
 				Booked: false,
 				Tag:    tag,
-				Type:   ResourceType,
+				Type:   resourceMonitor.Spec.Type,
 			},
 		}
 		log.Info("creating resources")
@@ -125,7 +97,7 @@ func (r *ResourceMonitorReconciler) Reconcile(ctx context.Context, req ctrl.Requ
 		}
 	}
 
-	return ctrl.Result{RequeueAfter: time.Duration(time.Second * 15)}, nil
+	return ctrl.Result{RequeueAfter: time.Duration(time.Minute * 2)}, nil
 }
 
 // SetupWithManager sets up the controller with the Manager.