feat(backup): add backup, restore, and reaper subsystems

Archive-based world backup and restore, plus the reaper that enforces retention and reclaims idle servers.

internal/reaper/k8scluster.go

@@ -0,0 +1,74 @@
+package reaper
+
+import (
+	"context"
+
+	"felis.lolicon.best/internal/apis/felis/v1alpha1"
+	"felis.lolicon.best/internal/naming"
+	corev1 "k8s.io/api/core/v1"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+)
+
+// WorldPVCName returns the world PVC name for a server. The convention
+// ("world-<name>-0") is owned by internal/naming because the operator, the
+// reaper, and restore all depend on it; this is a thin alias kept so existing
+// reaper call sites read naturally.
+func WorldPVCName(server string) string {
+	return naming.WorldPVCName(server)
+}
+
+// K8sCluster is the production Cluster backed by a controller-runtime client
+// (spec §4, §18). It reads spec.reaperExempt, deletes the world PVC, and flips
+// spec.desiredState to Stopped — nothing else. It is integration-tested against
+// a live cluster, not the hermetic reaper_test.go suite.
+type K8sCluster struct {
+	c         client.Client
+	namespace string
+}
+
+// NewK8sCluster builds a Cluster over c, scoped to namespace.
+func NewK8sCluster(c client.Client, namespace string) *K8sCluster {
+	return &K8sCluster{c: c, namespace: namespace}
+}
+
+func (k *K8sCluster) Inspect(ctx context.Context, name string) (ServerCRD, error) {
+	var ms v1alpha1.MinecraftServer
+	if err := k.c.Get(ctx, types.NamespacedName{Namespace: k.namespace, Name: name}, &ms); err != nil {
+		if apierrors.IsNotFound(err) {
+			return ServerCRD{}, ErrNotFound
+		}
+		return ServerCRD{}, err
+	}
+	return ServerCRD{Exempt: ms.Spec.ReaperExempt, PVC: WorldPVCName(name)}, nil
+}
+
+// DeletePVC deletes the world PersistentVolumeClaim. A missing PVC is not an
+// error: the reap is idempotent and a re-run after a partial failure must still
+// converge.
+func (k *K8sCluster) DeletePVC(ctx context.Context, pvc string) error {
+	obj := &corev1.PersistentVolumeClaim{
+		ObjectMeta: metav1.ObjectMeta{Namespace: k.namespace, Name: pvc},
+	}
+	if err := k.c.Delete(ctx, obj); err != nil && !apierrors.IsNotFound(err) {
+		return err
+	}
+	return nil
+}
+
+// Stop sets spec.desiredState=Stopped with a merge patch so a concurrent status
+// write by the operator is never clobbered (spec §9.1).
+func (k *K8sCluster) Stop(ctx context.Context, name string) error {
+	var ms v1alpha1.MinecraftServer
+	if err := k.c.Get(ctx, types.NamespacedName{Namespace: k.namespace, Name: name}, &ms); err != nil {
+		if apierrors.IsNotFound(err) {
+			return ErrNotFound
+		}
+		return err
+	}
+	patch := client.MergeFrom(ms.DeepCopy())
+	ms.Spec.DesiredState = v1alpha1.DesiredStopped
+	return k.c.Patch(ctx, &ms, patch)
+}