fix: throw an error when trying to create a flow with a reserved keyword id

close #5832

core/src/main/java/io/kestra/core/validations/validator/FlowValidator.java

@@ -36,6 +36,19 @@ import static io.kestra.core.models.Label.SYSTEM_PREFIX;
 @Singleton
 @Introspected
 public class FlowValidator implements ConstraintValidator<FlowValidation, Flow> {
+    public static List<String> RESERVED_FLOW_IDS = List.of(
+        "pause",
+        "resume",
+        "force-run",
+        "change-status",
+        "kill",
+        "executions",
+        "search",
+        "source",
+        "disable",
+        "enable"
+    );
+
     @Inject
     private FlowService flowService;
 
@@ -50,6 +63,10 @@ public class FlowValidator implements ConstraintValidator<FlowValidation, Flow>
 
         List<String> violations = new ArrayList<>();
 
+        if (RESERVED_FLOW_IDS.contains(value.getId())) {
+            violations.add("Flow id is a reserved keyword: " + value.getId() + ". List of reserved keywords: " + String.join(", ", RESERVED_FLOW_IDS));
+        }
+
         if (flowService.requireExistingNamespace(value.getTenantId(), value.getNamespace())) {
             violations.add("Namespace '" + value.getNamespace() + "' does not exist but is required to exist before a flow can be created in it.");
         }

core/src/test/java/io/kestra/core/services/FlowServiceTest.java

@@ -412,4 +412,23 @@ class FlowServiceTest {
             "The task 'for' cannot use the 'workerGroup' property as it's only relevant for runnable tasks."
         );
     }
+
+    @Test
+    void shouldReturnValidationErrorForReservedFlowId() {
+        // Given
+        String source = """
+        id: pause
+        namespace: io.kestra.unittest
+        tasks:
+          - id: task
+            type: io.kestra.plugin.core.log.Log
+            message: Reserved id test
+        """;
+        // When
+        List<ValidateConstraintViolation> results = flowService.validate("my-tenant", source);
+
+        // Then
+        assertThat(results).hasSize(1);
+        assertThat(results.getFirst().getConstraints()).contains("Flow id is a reserved keyword: pause");
+    }
 }