From 1c77d6597f6474fea879efa05b415c2198dceaee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Iv=C3=A1n=20Ovejero?= <ivov.src@gmail.com>
Date: Thu, 2 Nov 2023 14:16:22 +0100
Subject: [PATCH] refactor(core): Ensure only leader handles licensing in
 multi-main scenario (#7558)

https://linear.app/n8n/issue/PAY-953/ensure-only-main-instance-leader-handles-licensing
---
 packages/cli/src/License.ts                   | 11 ++++
 packages/cli/src/commands/BaseCommand.ts      | 11 ++++
 .../integration/commands/start.cmd.test.ts    | 53 +++++++++++++++++++
 3 files changed, 75 insertions(+)
 create mode 100644 packages/cli/test/integration/commands/start.cmd.test.ts

diff --git a/packages/cli/src/License.ts b/packages/cli/src/License.ts
index 81fceac16a..e99c387a86 100644
--- a/packages/cli/src/License.ts
+++ b/packages/cli/src/License.ts
@@ -113,6 +113,17 @@ export class License {
 
 	async onFeatureChange(_features: TFeatures): Promise<void> {
 		if (config.getEnv('executions.mode') === 'queue') {
+			if (config.getEnv('leaderSelection.enabled')) {
+				const { MultiMainInstancePublisher } = await import(
+					'@/services/orchestration/main/MultiMainInstance.publisher.ee'
+				);
+
+				if (Container.get(MultiMainInstancePublisher).isFollower) {
+					this.logger.debug('Instance is follower, skipping sending of reloadLicense command...');
+					return;
+				}
+			}
+
 			if (!this.redisPublisher) {
 				this.logger.debug('Initializing Redis publisher for License Service');
 				this.redisPublisher = await Container.get(RedisService).getPubSubPublisher();
diff --git a/packages/cli/src/commands/BaseCommand.ts b/packages/cli/src/commands/BaseCommand.ts
index 868f26d825..cbcbb3d70b 100644
--- a/packages/cli/src/commands/BaseCommand.ts
+++ b/packages/cli/src/commands/BaseCommand.ts
@@ -243,6 +243,17 @@ export abstract class BaseCommand extends Command {
 	}
 
 	async initLicense(): Promise<void> {
+		if (config.getEnv('executions.mode') === 'queue' && config.getEnv('leaderSelection.enabled')) {
+			const { MultiMainInstancePublisher } = await import(
+				'@/services/orchestration/main/MultiMainInstance.publisher.ee'
+			);
+
+			if (Container.get(MultiMainInstancePublisher).isFollower) {
+				this.logger.debug('Instance is follower, skipping license initialization...');
+				return;
+			}
+		}
+
 		const license = Container.get(License);
 		await license.init(this.instanceType ?? 'main');
 
diff --git a/packages/cli/test/integration/commands/start.cmd.test.ts b/packages/cli/test/integration/commands/start.cmd.test.ts
new file mode 100644
index 0000000000..47158a1c11
--- /dev/null
+++ b/packages/cli/test/integration/commands/start.cmd.test.ts
@@ -0,0 +1,53 @@
+import * as Config from '@oclif/config';
+
+import { mockInstance } from '../shared/utils';
+
+import { Start } from '@/commands/start';
+import { BaseCommand } from '@/commands/BaseCommand';
+import config from '@/config';
+import { License } from '@/License';
+
+import { ExternalSecretsManager } from '@/ExternalSecrets/ExternalSecretsManager.ee';
+import { MultiMainInstancePublisher } from '@/services/orchestration/main/MultiMainInstance.publisher.ee';
+import { ActiveWorkflowRunner } from '@/ActiveWorkflowRunner';
+import { WorkflowHistoryManager } from '@/workflows/workflowHistory/workflowHistoryManager.ee';
+import { RedisService } from '@/services/redis.service';
+import { RedisServicePubSubPublisher } from '@/services/redis/RedisServicePubSubPublisher';
+import { RedisServicePubSubSubscriber } from '@/services/redis/RedisServicePubSubSubscriber';
+import { OrchestrationHandlerMainService } from '@/services/orchestration/main/orchestration.handler.main.service';
+
+const oclifConfig: Config.IConfig = new Config.Config({ root: __dirname });
+
+beforeAll(() => {
+	mockInstance(ExternalSecretsManager);
+	mockInstance(ActiveWorkflowRunner);
+	mockInstance(WorkflowHistoryManager);
+	mockInstance(RedisService);
+	mockInstance(RedisServicePubSubPublisher);
+	mockInstance(RedisServicePubSubSubscriber);
+	mockInstance(MultiMainInstancePublisher);
+	mockInstance(OrchestrationHandlerMainService);
+});
+
+afterEach(() => {
+	config.load(config.default);
+	jest.restoreAllMocks();
+});
+
+test('should not init license if instance is follower in multi-main scenario', async () => {
+	config.set('executions.mode', 'queue');
+	config.set('leaderSelection.enabled', true);
+
+	jest.spyOn(MultiMainInstancePublisher.prototype, 'isFollower', 'get').mockReturnValue(true);
+	jest.spyOn(BaseCommand.prototype, 'init').mockImplementation(async () => {});
+
+	const licenseMock = mockInstance(License, {
+		isMultipleMainInstancesLicensed: jest.fn().mockReturnValue(true),
+	});
+
+	const startCmd = new Start([], oclifConfig);
+
+	await startCmd.init();
+
+	expect(licenseMock.init).not.toHaveBeenCalled();
+});