diff --git a/cmd/felis/operator.go b/cmd/felis/operator.go index 3a3534e..40c9b30 100644 --- a/cmd/felis/operator.go +++ b/cmd/felis/operator.go @@ -117,8 +117,11 @@ func cmdOperator(args []string, _, stderr io.Writer) int { FelisImage: os.Getenv("FELIS_IMAGE"), // Uncached: the maintenance-lock check lists Jobs only when a server is // about to start, which does not justify a namespace-wide Job informer. - Jobs: mgr.GetAPIReader(), - Watch: watch, + Jobs: mgr.GetAPIReader(), + // Uncached too: RCON Secrets are read by name, so the Role grants + // secrets:get without the list/watch an informer would need. + Secrets: mgr.GetAPIReader(), + Watch: watch, } if err := r.SetupWithManager(mgr); err != nil { fmt.Fprintf(stderr, "felis operator: setup controller: %v\n", err) diff --git a/internal/operator/autorestart_test.go b/internal/operator/autorestart_test.go index fe91c3f..b03ed58 100644 --- a/internal/operator/autorestart_test.go +++ b/internal/operator/autorestart_test.go @@ -10,6 +10,7 @@ import ( 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" "felis.lolicon.best/internal/apis/felis/v1alpha1" "felis.lolicon.best/internal/operator" @@ -182,3 +183,64 @@ func TestFailedServerRequeuesWhenTheRetryIsDue(t *testing.T) { t.Fatalf("spent requeue = %v, want 5m", res.RequeueAfter) } } + +// noCachedSecrets stands in for the manager's cached client, which has no Secret +// informer: any Secret read through it fails. +type noCachedSecrets struct{ client.Client } + +func (c noCachedSecrets) Get(ctx context.Context, key client.ObjectKey, obj client.Object, opts ...client.GetOption) error { + if _, ok := obj.(*corev1.Secret); ok { + return errors.New("secrets are not cached") + } + return c.Client.Get(ctx, key, obj, opts...) +} + +// RCON Secrets are provisioned and read through Reconciler.Secrets alone, so the +// operator runs with secrets:get and no Secret informer. +func TestRconSecretsAreReadThroughTheUncachedReader(t *testing.T) { + r, c := newReconciler(t, fakeProber{players: operator.PlayerCount{Online: 2, Max: 20}}, runningServer()) + r.Client = noCachedSecrets{c} + r.Secrets = c + reconcile(t, r, "survival") // provisions survival-rcon + var secret corev1.Secret + if err := c.Get(context.Background(), types.NamespacedName{Namespace: "minecraft", Name: "survival-rcon"}, &secret); err != nil { + t.Fatalf("rcon secret not provisioned: %v", err) + } + markPodReady(t, c, "survival") + reconcile(t, r, "survival") + if s := getServer(t, c, "survival"); s.Status.Phase != v1alpha1.PhaseRunning || !s.Status.Ready { + t.Fatalf("phase=%s ready=%v, want Running ready", s.Status.Phase, s.Status.Ready) + } +} + +// staleOnce answers the first Secret Get NotFound, like a reader that lost the +// race to a concurrent create, then reads through. +type staleOnce struct { + client.Reader + missed bool +} + +func (s *staleOnce) Get(ctx context.Context, key client.ObjectKey, obj client.Object, opts ...client.GetOption) error { + if !s.missed { + s.missed = true + return apierrors.NewNotFound(corev1.Resource("secrets"), key.Name) + } + return s.Reader.Get(ctx, key, obj, opts...) +} + +// Losing the create race re-reads the winner through the same uncached reader. +func TestRconSecretCreateRaceRereadsUncached(t *testing.T) { + r, c := newReconciler(t, fakeProber{}, runningServer(), rconSecret()) + r.Client = noCachedSecrets{c} + r.Secrets = &staleOnce{Reader: c} + reconcile(t, r, "survival") + var secret corev1.Secret + if err := c.Get(context.Background(), types.NamespacedName{Namespace: "minecraft", Name: "survival-rcon"}, &secret); err != nil { + t.Fatal(err) + } + if got := string(secret.Data["password"]); got != "hunter2" { + t.Fatalf("password = %q, want the winner's hunter2", got) + } + // The pass went on to build the workload instead of parking on RconSecretUnavailable. + getSTS(t, c, "survival") +} diff --git a/internal/operator/reconciler.go b/internal/operator/reconciler.go index 7f9b4ef..02d138f 100644 --- a/internal/operator/reconciler.go +++ b/internal/operator/reconciler.go @@ -122,6 +122,12 @@ type Reconciler struct { // (internal/maintenance). It is the manager's uncached API reader, so the // operator needs jobs:list and no Job informer. Nil skips the check. Jobs client.Reader + // Secrets reads the RCON password Secrets, each by name. It is the manager's + // uncached API reader, so the operator holds secrets:get and no list or watch: + // a Secret informer would cache every Secret in the namespace (the felis-config + // mirror with the database URL among them) and grow with them. Nil falls back + // to the embedded client. + Secrets client.Reader // Watch records the passes in flight for the liveness probe. Nil skips it. Watch *ReconcileWatch @@ -146,10 +152,9 @@ func (r *Reconciler) SetupWithManager(mgr ctrl.Manager) error { For(&v1alpha1.MinecraftServer{}). Owns(&appsv1.StatefulSet{}). Owns(&corev1.Service{}). - // Owns the Secrets too: the per-server RCON password is managed here, - // and a watch is what lets a deleted Secret be noticed at all (a quiet - // Running server otherwise produces no events). - Owns(&corev1.Secret{}). + // No Secret watch: a Running server is re-reconciled every + // requeueRunningProbe anyway, which recreates a deleted RCON Secret, and + // a stopped one gets it back on its next start. WithOptions(controller.Options{MaxConcurrentReconciles: maxConcurrentReconciles}). Complete(r) } @@ -522,7 +527,7 @@ func (r *Reconciler) ensureRconSecret(ctx context.Context, server *v1alpha1.Mine return "", fmt.Errorf("rcon.secretRef.name and .key are required when rcon is enabled") } var existing corev1.Secret - err := r.Get(ctx, types.NamespacedName{Namespace: server.Namespace, Name: ref.Name}, &existing) + err := r.secretReader().Get(ctx, types.NamespacedName{Namespace: server.Namespace, Name: ref.Name}, &existing) if err == nil { if b, ok := existing.Data[ref.Key]; ok { return rconStamp(b), nil @@ -561,7 +566,7 @@ func (r *Reconciler) ensureRconSecret(ctx context.Context, server *v1alpha1.Mine // value that would flip on the next reconcile and roll the pod twice. if apierrors.IsAlreadyExists(err) { var winner corev1.Secret - if gerr := r.Get(ctx, types.NamespacedName{Namespace: server.Namespace, Name: ref.Name}, &winner); gerr != nil { + if gerr := r.secretReader().Get(ctx, types.NamespacedName{Namespace: server.Namespace, Name: ref.Name}, &winner); gerr != nil { return "", gerr } return rconStamp(winner.Data[ref.Key]), nil @@ -583,13 +588,20 @@ func randomRconPassword() (string, error) { return hex.EncodeToString(b[:]), nil } +func (r *Reconciler) secretReader() client.Reader { + if r.Secrets != nil { + return r.Secrets + } + return r.Client +} + func (r *Reconciler) rconPassword(ctx context.Context, server *v1alpha1.MinecraftServer) (string, error) { ref := server.Spec.Rcon.SecretRef if ref.Name == "" || ref.Key == "" { return "", fmt.Errorf("rcon.secretRef.name and .key are required when rcon is enabled") } var secret corev1.Secret - if err := r.Get(ctx, types.NamespacedName{Namespace: server.Namespace, Name: ref.Name}, &secret); err != nil { + if err := r.secretReader().Get(ctx, types.NamespacedName{Namespace: server.Namespace, Name: ref.Name}, &secret); err != nil { return "", err } b, ok := secret.Data[ref.Key] diff --git a/internal/platform/rbac.go b/internal/platform/rbac.go index 4ac3573..1608451 100644 --- a/internal/platform/rbac.go +++ b/internal/platform/rbac.go @@ -150,7 +150,7 @@ func APIBuildRole(p Params) *rbacv1.Role { // status (Status().Update — `update` only) and patches spec.desiredState to // Stopped for idle auto-stop (spec §8 — the one spec field it may write, using // the same merge patch as the reaper's Stop: without the grant the auto-stop -// call fails closed with a 403), and reads RCON Secrets. Jobs are list-only, +// call fails closed with a 403), and reads RCON Secrets by name, uncached. Jobs are list-only, // through the manager's uncached API reader: before scaling a server up from zero // the operator checks that no restore/backup/file-write Job holds its world // (internal/maintenance). Pods are delete-only: a start that timed out is retried @@ -164,13 +164,13 @@ func OperatorRole(p Params) *rbacv1.Role { rule([]string{groupFelis}, []string{"minecraftservers/status"}, []string{"update"}), rule([]string{groupApps}, []string{"statefulsets"}, []string{"get", "list", "watch", "create", "update"}), rule([]string{groupCore}, []string{"services"}, []string{"get", "list", "watch", "create", "update"}), - // create is here for the per-server RCON password Secret the operator - // provisions on first reconcile (internal/operator.ensureRconSecret). It is a - // smaller grant than it looks: this identity already holds get/list/watch on - // every Secret in this namespace, so being able to add one grants no read it - // did not already have. No update/delete — the password is written once and + // get by name, through the uncached API reader (Reconciler.Secrets), of the + // RCON password Secret a server's spec names; create for the one the operator + // provisions on first reconcile (internal/operator.ensureRconSecret). No + // list/watch, so there is no Secret informer and nothing enumerates the + // namespace's Secrets. No update/delete — the password is written once and // removed by garbage collection through its controller reference. - rule([]string{groupCore}, []string{"secrets"}, []string{"get", "list", "watch", "create"}), + rule([]string{groupCore}, []string{"secrets"}, []string{"get", "create"}), // list only: an uncached List (no informer, so no watch) of the world-volume // maintenance Jobs; the operator never creates or deletes a Job. rule([]string{groupBatch}, []string{"jobs"}, []string{"list"}), diff --git a/internal/platform/rbac_test.go b/internal/platform/rbac_test.go index 189baf6..2e91cee 100644 --- a/internal/platform/rbac_test.go +++ b/internal/platform/rbac_test.go @@ -194,6 +194,18 @@ func TestOperatorRole_ScopeExact(t *testing.T) { t.Errorf("operator must NOT touch core/%s", res) } } + // RCON Secrets are read by name through the uncached reader and created once; + // no list/watch, so no informer mirrors the namespace's Secrets into it. + for _, v := range []string{"get", "create"} { + if !hasRule(op, groupCore, "secrets", v) { + t.Errorf("operator must have secrets:%s", v) + } + } + for _, v := range []string{"list", "watch", "update", "patch", "delete", "deletecollection", "*"} { + if hasRule(op, groupCore, "secrets", v) { + t.Errorf("operator secrets rule must be get+create only, found %s", v) + } + } // Pods are delete-only: the bounded retry of a timed-out start. if !hasRule(op, groupCore, "pods", "delete") { t.Error("operator must have pods:delete (auto-restart of a timed-out start)") diff --git a/internal/platform/workloads.go b/internal/platform/workloads.go index 11e3e14..64fcf7e 100644 --- a/internal/platform/workloads.go +++ b/internal/platform/workloads.go @@ -540,8 +540,11 @@ func operatorMetricsService(p Params) *corev1.Service { // the felis-operator SA and carries controlPlanePodLabels(operator), the second // pod the allow-rcon peer admits (the readiness prober dials RCON). It takes NO // config Secret: the operator reads everything from flags + the in-cluster API, -// so it never holds the database URL — a deliberately smaller attack surface than -// the api. It watches the minecraft namespace (--namespace) while running in the +// so it never loads the database URL — a deliberately smaller attack surface than +// the api. Its secrets:get in the minecraft namespace is by name and uncached +// (no list, no informer), yet namespaced RBAC cannot exclude a name, so a +// compromised operator could still fetch the felis-config mirror the Jobs and +// the reaper mount there. It watches the minecraft namespace (--namespace) while running in the // control namespace, exactly the split cmd/felis/operator.go documents. func OperatorDeployment(p Params) *appsv1.Deployment { p = p.withDefaults()