nestjs-sentry-example: A TypeScript repository from nirajkvinit

Description

Simple Sentry setup on Nest framework. Just explore the code for more details, especially the files in the sentry folder.

Installation

To run this simple example, clone this repository and install the dependencies. Then copy .env.sample to .env and insert your own Sentry DNS.

You can find DNS for your project on Sentry.io in Project Setting / Client Keys.

Then run Nest using the usual command:

npm run start:debug

Testing and Sample Error

Once the Nest.js server is running you can go to http://localhost:3000/throw, it will create a sample error in your Sentry project.

Or you can run the E2E test:

npm run test:e2e

In the test/load directory you will find two Artillery scripts to test the performance of your application. You can run them using the following commands:

npx artillery run smoke-test.yml

Be careful not to eat all your quota on Sentry.

Step by step

Below are some explanations on how to do a clean setup from scratch in your existing project.

Dependencies

Create a new Nest app using the CLI

nest new sentry-setup

Install Sentry

npm i --save @sentry/node @sentry/profiling-node

Create the needed elements

Create Sentry module, service and interceptor

nest g module sentry
nest g interceptor sentry
nest g filter sentry/sentry-exception --flat

SentryModule

Create the SentryModule.forRoot() method and add the Sentry.init(options) in it.

Call the SentryModule.forRoot({...}) in the AppModule.

Add the call to the Express requestHandler middleware in the AppModule.

  configure(consumer
:
MiddlewareConsumer
):
void {
  consumer.apply(Sentry.Handlers.requestHandler()).forRoutes({
    path: '*',
    method: RequestMethod.ALL,
  });
}

It is important to use that middleware otherwise the current Hub will be global, and you will run into conflicts as Sentry create a Hub by thread and Node.js is not multi-thread.

SentryInterceptor

The SentryInterceptor will start the transaction, and finish it after the route was handled.

@Injectable()
export class SentryInterceptor implements NestInterceptor {
  constructor(private sentryService: SentryService) {
  }

  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
    const request = context.switchToHttp().getRequest();
    const { method, url } = request;

    // Start the Sentry transaction
    const transaction = Sentry.startTransaction({
      op: 'http.server',
      name: `${method} ${url}`,
    });

    // ... etc ...
  }
}

As an example I added a span. This is not necessary, but it will make the trace nicer in the performance tab of Sentry.

You can add more span anywhere in your application simply by using Sentry.getCurrentHub().

SentryExceptionFilter

This is where the exception are caught and sent to Sentry.

nirajkvinit/nestjs-sentry-example