refactor(core): Add shutdown method to modules (#17322)

packages/@n8n/backend-common/src/modules/module-registry.ts

@@ -113,6 +113,22 @@ export class ModuleRegistry {
 		}
 	}
 
+	async shutdownModule(moduleName: ModuleName) {
+		const moduleEntry = this.moduleMetadata.get(moduleName);
+
+		if (!moduleEntry) {
+			this.logger.debug('Skipping shutdown for unregistered module', { moduleName });
+			return;
+		}
+
+		await Container.get(moduleEntry.class).shutdown?.();
+
+		const index = this.activeModules.indexOf(moduleName);
+		if (index > -1) this.activeModules.splice(index, 1);
+
+		this.logger.debug(`Shut down module "${moduleName}"`);
+	}
+
 	isActive(moduleName: ModuleName) {
 		return this.activeModules.includes(moduleName);
 	}

packages/@n8n/decorators/src/module/module-metadata.ts

@@ -15,6 +15,10 @@ export class ModuleMetadata {
 		this.modules.set(moduleName, moduleEntry);
 	}
 
+	get(moduleName: string) {
+		return this.modules.get(moduleName);
+	}
+
 	getEntries() {
 		return [...this.modules.entries()];
 	}

packages/@n8n/decorators/src/module/module.ts

@@ -22,6 +22,7 @@ export type ModuleSettings = Record<string, unknown>;
 
 export interface ModuleInterface {
 	init?(): Promise<void>;
+	shutdown?(): Promise<void>;
 	entities?(): Promise<EntityClass[]>;
 	settings?(): Promise<ModuleSettings>;
 }

packages/@n8n/decorators/src/shutdown/__tests__/on-shutdown.test.ts

@@ -1,15 +1,15 @@
 import { Container, Service } from '@n8n/di';
 
 import { OnShutdown } from '../on-shutdown';
-import { ShutdownRegistryMetadata } from '../shutdown-registry-metadata';
+import { ShutdownMetadata } from '../shutdown-metadata';
 
 describe('OnShutdown', () => {
-	let shutdownRegistryMetadata: ShutdownRegistryMetadata;
+	let shutdownMetadata: ShutdownMetadata;
 
 	beforeEach(() => {
-		shutdownRegistryMetadata = new ShutdownRegistryMetadata();
-		Container.set(ShutdownRegistryMetadata, shutdownRegistryMetadata);
-		jest.spyOn(shutdownRegistryMetadata, 'register');
+		shutdownMetadata = new ShutdownMetadata();
+		Container.set(ShutdownMetadata, shutdownMetadata);
+		jest.spyOn(shutdownMetadata, 'register');
 	});
 
 	it('should register a methods that is decorated with OnShutdown', () => {
@@ -19,8 +19,8 @@ describe('OnShutdown', () => {
 			async onShutdown() {}
 		}
 
-		expect(shutdownRegistryMetadata.register).toHaveBeenCalledTimes(1);
-		expect(shutdownRegistryMetadata.register).toHaveBeenCalledWith(100, {
+		expect(shutdownMetadata.register).toHaveBeenCalledTimes(1);
+		expect(shutdownMetadata.register).toHaveBeenCalledWith(100, {
 			methodName: 'onShutdown',
 			serviceClass: TestClass,
 		});
@@ -36,12 +36,12 @@ describe('OnShutdown', () => {
 			async two() {}
 		}
 
-		expect(shutdownRegistryMetadata.register).toHaveBeenCalledTimes(2);
-		expect(shutdownRegistryMetadata.register).toHaveBeenCalledWith(100, {
+		expect(shutdownMetadata.register).toHaveBeenCalledTimes(2);
+		expect(shutdownMetadata.register).toHaveBeenCalledWith(100, {
 			methodName: 'one',
 			serviceClass: TestClass,
 		});
-		expect(shutdownRegistryMetadata.register).toHaveBeenCalledWith(100, {
+		expect(shutdownMetadata.register).toHaveBeenCalledWith(100, {
 			methodName: 'two',
 			serviceClass: TestClass,
 		});
@@ -56,9 +56,9 @@ describe('OnShutdown', () => {
 			}
 		}
 
-		expect(shutdownRegistryMetadata.register).toHaveBeenCalledTimes(1);
+		expect(shutdownMetadata.register).toHaveBeenCalledTimes(1);
 		// @ts-expect-error We are checking internal parts of the shutdown service
-		expect(shutdownRegistryMetadata.handlersByPriority[10].length).toEqual(1);
+		expect(shutdownMetadata.handlersByPriority[10].length).toEqual(1);
 	});
 
 	it('should throw an error if the decorated member is not a function', () => {

packages/@n8n/decorators/src/shutdown/index.ts

@@ -3,6 +3,6 @@ export {
 	DEFAULT_SHUTDOWN_PRIORITY,
 	LOWEST_SHUTDOWN_PRIORITY,
 } from './constants';
-export { ShutdownRegistryMetadata } from './shutdown-registry-metadata';
+export { ShutdownMetadata } from './shutdown-metadata';
 export { OnShutdown } from './on-shutdown';
 export type { ShutdownHandler, ShutdownServiceClass } from './types';

packages/@n8n/decorators/src/shutdown/on-shutdown.ts

@@ -2,7 +2,7 @@ import { Container } from '@n8n/di';
 import { UnexpectedError } from 'n8n-workflow';
 
 import { DEFAULT_SHUTDOWN_PRIORITY } from './constants';
-import { ShutdownRegistryMetadata } from './shutdown-registry-metadata';
+import { ShutdownMetadata } from './shutdown-metadata';
 import type { ShutdownServiceClass } from './types';
 
 /**
@@ -31,7 +31,7 @@ export const OnShutdown =
 		const methodName = String(propertyKey);
 		// TODO: assert that serviceClass is decorated with @Service
 		if (typeof descriptor?.value === 'function') {
-			Container.get(ShutdownRegistryMetadata).register(priority, { serviceClass, methodName });
+			Container.get(ShutdownMetadata).register(priority, { serviceClass, methodName });
 		} else {
 			const name = `${serviceClass.name}.${methodName}()`;
 			throw new UnexpectedError(

packages/@n8n/decorators/src/shutdown/shutdown-metadata.ts

@@ -5,7 +5,7 @@ import { HIGHEST_SHUTDOWN_PRIORITY, LOWEST_SHUTDOWN_PRIORITY } from './constants
 import type { ShutdownHandler } from './types';
 
 @Service()
-export class ShutdownRegistryMetadata {
+export class ShutdownMetadata {
 	private handlersByPriority: ShutdownHandler[][] = [];
 
 	register(priority: number, handler: ShutdownHandler) {