fix(backends): Backend-Löschen verweigern wenn Routing-Regeln darauf zeigen (v1.1.142)

- Service: Pre-Check auf routing_rules.backend_id → ErrInUse vor DELETE
- Handler: ErrInUse → HTTP 409 Conflict statt 500 (response.Conflict helper)
- UI: Delete-Button deaktiviert + Tooltip "Von N Regeln verwendet" wenn Referenzen existieren

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

VERSION

@@ -1 +1 @@
-1.1.141
+1.1.142

cmd/edgeguard-api/main.go

@@ -60,7 +60,7 @@ import (
 	usersvc "git.netcell-it.de/projekte/edgeguard-native/internal/services/users"
 )
 
-var version = "1.1.141"
+var version = "1.1.142"
 
 func main() {
 	addr := os.Getenv("EDGEGUARD_API_ADDR")

cmd/edgeguard-ctl/main.go

@@ -11,7 +11,7 @@ import (
 	"git.netcell-it.de/projekte/edgeguard-native/internal/services/setup"
 )
 
-var version = "1.1.141"
+var version = "1.1.142"
 
 const usage = `edgeguard-ctl — EdgeGuard CLI
 

cmd/edgeguard-scheduler/main.go

@@ -41,7 +41,7 @@ import (
 	"git.netcell-it.de/projekte/edgeguard-native/internal/services/tlscerts"
 )
 
-var version = "1.1.141"
+var version = "1.1.142"
 
 const (
 	// renewTickInterval — how often we re-evaluate expiring certs.

internal/handlers/backends.go

@@ -117,6 +117,10 @@ func (h *BackendsHandler) Delete(c *gin.Context) {
 			response.NotFound(c, err)
 			return
 		}
+		if errors.Is(err, backends.ErrInUse) {
+			response.Conflict(c, err)
+			return
+		}
 		response.Internal(c, err)
 		return
 	}

internal/handlers/response/response.go

@@ -82,6 +82,10 @@ func Forbidden(c *gin.Context, err error) {
 	Err(c, http.StatusForbidden, err)
 }
 
+func Conflict(c *gin.Context, err error) {
+	Err(c, http.StatusConflict, err)
+}
+
 func Internal(c *gin.Context, err error) {
 	Err(c, http.StatusInternalServerError, err)
 }

internal/services/backends/backends.go

@@ -14,7 +14,10 @@ import (
 	"git.netcell-it.de/projekte/edgeguard-native/internal/models"
 )
 
-var ErrNotFound = errors.New("backend not found")
+var (
+	ErrNotFound = errors.New("backend not found")
+	ErrInUse    = errors.New("backend is referenced by one or more routing rules")
+)
 
 type Repo struct {
 	Pool *pgxpool.Pool
@@ -99,6 +102,15 @@ RETURNING id, name, scheme, health_check_path, lb_algorithm, websocket, force_ht
 }
 
 func (r *Repo) Delete(ctx context.Context, id int64) error {
+	var n int
+	if err := r.Pool.QueryRow(ctx,
+		`SELECT COUNT(*) FROM routing_rules WHERE backend_id = $1`, id,
+	).Scan(&n); err != nil {
+		return err
+	}
+	if n > 0 {
+		return ErrInUse
+	}
 	tag, err := r.Pool.Exec(ctx, `DELETE FROM backends WHERE id = $1`, id)
 	if err != nil {
 		return err

management-ui/src/i18n/locales/de/common.json

@@ -387,6 +387,7 @@
     "serverHintCreate": "Speichern legt nur den Pool an. Server kommen im nächsten Schritt — Pool öffnen → „Server hinzufügen\".",
     "actions": "Aktionen",
     "deleteConfirm": "Backend-Pool {{name}} wirklich löschen? Alle Server im Pool werden mitentfernt.",
+    "deleteInUse": "Von {{n}} Routing-Regel(n) verwendet — zuerst diese löschen",
     "backToList": "Zurück zur Übersicht",
     "settingsCard": "Pool-Einstellungen",
     "healthCheckHint": "HTTP-Pfad den HAProxy alle 5s pro Server prüft. Leer lassen = kein Health-Check.",

management-ui/src/i18n/locales/en/common.json

@@ -387,6 +387,7 @@
     "serverHintCreate": "Saving creates the pool only. Add servers in the next step — open the pool and click “Add server”.",
     "actions": "Actions",
     "deleteConfirm": "Really delete backend pool {{name}}? All servers in the pool will be removed too.",
+    "deleteInUse": "Used by {{n}} routing rule(s) — remove those first",
     "backToList": "Back to backends",
     "settingsCard": "Pool settings",
     "healthCheckHint": "HTTP path HAProxy probes every 5s per server. Leave empty to disable health checks.",

management-ui/src/pages/Backends/index.tsx

@@ -97,6 +97,15 @@ async function listDomains(): Promise<DomainFull[]> {
   return (r.data.data as { domains?: DomainFull[] }).domains ?? []
 }
 
+interface RoutingRule { id: number; backend_id: number }
+async function listRoutingRules(): Promise<RoutingRule[]> {
+  try {
+    const r = await apiClient.get('/routing-rules')
+    if (!isEnvelope(r.data)) return []
+    return (r.data.data as { routing_rules?: RoutingRule[] }).routing_rules ?? []
+  } catch { return [] }
+}
+
 interface HAProxyStat {
   backend: string; server: string; status: string
   sessions: number; bytes_in: number; bytes_out: number
@@ -124,6 +133,7 @@ export default function BackendsPage() {
 
   const { data, isLoading } = useQuery({ queryKey: ['backends'], queryFn: listBackends })
   const { data: domains } = useQuery({ queryKey: ['domains'], queryFn: listDomains })
+  const { data: routingRules } = useQuery({ queryKey: ['routing-rules'], queryFn: listRoutingRules })
   const { data: services } = useQuery({
     queryKey: ['system', 'services'],
     queryFn: async () => {
@@ -177,6 +187,9 @@ export default function BackendsPage() {
   const domainsForBackend = (id: number) =>
     (domains ?? []).filter(d => d.primary_backend_id === id)
 
+  const ruleCountForBackend = (id: number) =>
+    (routingRules ?? []).filter(r => r.backend_id === id).length
+
   const [creating, setCreating] = useState(false)
   const [form] = Form.useForm<BackendFormValues>()
 
@@ -296,13 +309,18 @@ export default function BackendsPage() {
     },
     {
       title: t('common.actions'), key: 'actions',
-      render: (_, row) => (
-        <ActionButtons
-          onEdit={() => navigate(`/backends/${row.id}`)}
-          onDelete={() => del.mutate(row.id)}
-          deleteConfirm={t('backends.deleteConfirm', { name: row.name })}
-        />
-      ),
+      render: (_, row) => {
+        const n = ruleCountForBackend(row.id)
+        return (
+          <ActionButtons
+            onEdit={() => navigate(`/backends/${row.id}`)}
+            onDelete={() => del.mutate(row.id)}
+            deleteConfirm={t('backends.deleteConfirm', { name: row.name })}
+            deleteDisabled={n > 0}
+            deleteDisabledReason={t('backends.deleteInUse', { n })}
+          />
+        )
+      },
     },
   ]