Enable safe NPM replica convergence

dns_sync/executor.py

@@ -314,6 +314,17 @@ def _required_capability(
         )
 
 
+def _required_retirement_support(
+    adapter: ExecutionAdapter,
+) -> None:
+    retire = getattr(adapter, "retire", None)
+    if not callable(retire):
+        raise RuntimeError(
+            f"{adapter.endpoint.identity} adapter does not support "
+            "deferred retirement"
+        )
+
+
 def _preflight(
     adapters: Iterable[ExecutionAdapter],
     plans: Iterable[EndpointPlan],
@@ -345,6 +356,9 @@ def _preflight(
                 f"No adapter for endpoint plan {plan.endpoint_id}"
             )
 
+        if plan.retirements:
+            _required_retirement_support(adapter)
+
         for retirement in plan.retirements:
             planned_retirements.append(
                 (
@@ -381,6 +395,9 @@ def _preflight(
                     "Executable plan action requires desired state"
                 )
 
+            if action.operation == PlanOperation.REPLACE:
+                _required_retirement_support(adapter)
+
             object_type = action.desired.object_type
             _required_capability(
                 adapter,