Implement group resource (#181)

This change implements a new group resource. 

It also sets the standard for a resource reference will be done through
out the controller. A resource reference can either be done by ID or as
a local named reference to the actual resource. This allows end users to
chose if they want to manage things completely in the cluster or not.

Part of #172

Signed-off-by: Philip Laine <philip.laine@gmail.com>

internal/controller/group_controller.go

@@ -0,0 +1,103 @@
+package controller
+
+import (
+	"context"
+
+	netbird "github.com/netbirdio/netbird/shared/management/client/rest"
+	"github.com/netbirdio/netbird/shared/management/http/api"
+	ctrl "sigs.k8s.io/controller-runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	nbv1alpha1 "github.com/netbirdio/kubernetes-operator/api/v1alpha1"
+	nbv1alpha1ac "github.com/netbirdio/kubernetes-operator/pkg/applyconfigurations/api/v1alpha1"
+)
+
+const (
+	GroupFinalizer = "netbird.io/group"
+)
+
+// GroupReconciler reconciles a Group object
+type GroupReconciler struct {
+	client.Client
+
+	Netbird *netbird.Client
+}
+
+// +kubebuilder:rbac:groups=netbird.io,resources=groups,verbs=get;list;watch;create;update;patch;delete
+// +kubebuilder:rbac:groups=netbird.io,resources=groups/status,verbs=get;update;patch
+// +kubebuilder:rbac:groups=netbird.io,resources=groups/finalizers,verbs=update
+func (r *GroupReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
+	group := nbv1alpha1.Group{}
+	err := r.Get(ctx, req.NamespacedName, &group)
+	if err != nil {
+		return ctrl.Result{}, client.IgnoreNotFound(err)
+	}
+
+	if !group.DeletionTimestamp.IsZero() {
+		return r.reconcileDelete(ctx, group)
+	}
+
+	groupAC := nbv1alpha1ac.Group(req.Name, req.Namespace).WithFinalizers(SetupKeyFinalizer)
+	err = r.Client.Apply(ctx, groupAC)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+
+	groupID, err := func() (string, error) {
+		if group.Status.GroupID != nil {
+			groupReq := api.GroupRequest{
+				Name: group.Spec.Name,
+			}
+			resp, err := r.Netbird.Groups.Update(ctx, *group.Status.GroupID, groupReq)
+			if err != nil && !netbird.IsNotFound(err) {
+				return "", err
+			}
+			if err == nil {
+				return resp.Id, nil
+			}
+		}
+
+		groupReq := api.GroupRequest{
+			Name: group.Spec.Name,
+		}
+		resp, err := r.Netbird.Groups.Create(ctx, groupReq)
+		if err != nil {
+			return "", err
+		}
+		return resp.Id, nil
+	}()
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+
+	groupAC = nbv1alpha1ac.Group(req.Name, req.Namespace).WithStatus(nbv1alpha1ac.GroupStatus().WithGroupID(groupID))
+	err = r.Client.Status().Apply(ctx, groupAC)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+
+	return ctrl.Result{}, nil
+}
+
+func (r *GroupReconciler) reconcileDelete(ctx context.Context, group nbv1alpha1.Group) (ctrl.Result, error) {
+	if group.Status.GroupID != nil {
+		err := r.Netbird.Groups.Delete(ctx, *group.Status.GroupID)
+		if err != nil && !netbird.IsNotFound(err) {
+			return ctrl.Result{}, err
+		}
+	}
+
+	groupAC := nbv1alpha1ac.Group(group.Name, group.Namespace).WithFinalizers()
+	err := r.Client.Apply(ctx, groupAC)
+	if err != nil {
+		return ctrl.Result{}, err
+	}
+	return ctrl.Result{}, nil
+}
+
+// SetupWithManager sets up the controller with the Manager.
+func (r *GroupReconciler) SetupWithManager(mgr ctrl.Manager) error {
+	return ctrl.NewControllerManagedBy(mgr).
+		For(&nbv1alpha1.Group{}).
+		Complete(r)
+}