feat(API): Set up error tracking using Sentry (#4394)

* feat(cli): Setup error tracking using Sentry

* make error reporting available in the workflows package

* address some of the PR comments

* create a ErrorReporterProxy like LoggerProxy

* remove the `captureError` helper. use ErrorReporterProxy directly

* fix linting issues

* remove ErrorReporterProxy warnings in tests

* check for NODE_ENV === 'production' instead

* IErrorReporter -> ErrorReporter

* ErrorReporterProxy.getInstance() -> ErrorReporter

* allow capturing stacks in warnings as well

* make n8n debugging consistent with `npm start`

* IReportingOptions -> ReportingOptions

* use consistent signature for `error` and `warn`

* use Logger instead of console.log

packages/cli/src/ErrorReporting.ts

@@ -0,0 +1,41 @@
+import * as Sentry from '@sentry/node';
+import { RewriteFrames } from '@sentry/integrations';
+import type { Application } from 'express';
+import config from '../config';
+import { ErrorReporterProxy } from 'n8n-workflow';
+
+let initialized = false;
+
+export const initErrorHandling = (app?: Application) => {
+	if (initialized) return;
+
+	if (!config.getEnv('diagnostics.enabled')) {
+		initialized = true;
+		return;
+	}
+
+	const dsn = config.getEnv('diagnostics.config.sentry.dsn');
+	const { N8N_VERSION: release, ENVIRONMENT: environment } = process.env;
+
+	Sentry.init({
+		dsn,
+		release,
+		environment,
+		integrations: (integrations) => {
+			integrations.push(new RewriteFrames({ root: process.cwd() }));
+			return integrations;
+		},
+	});
+
+	if (app) {
+		const { requestHandler, errorHandler } = Sentry.Handlers;
+		app.use(requestHandler());
+		app.use(errorHandler());
+	}
+
+	ErrorReporterProxy.init({
+		report: (error, options) => Sentry.captureException(error, options),
+	});
+
+	initialized = true;
+};