Why?

When debugging an issue in your applications logs, it helps to be able to follow a specific request up and down your whole stack. This is usually done by including a correlation-id (aka Request-id) header in all your requests, and forwarding the same id across all your microservices.

Installation

yarn add @evanion/nestjs-correlation-id

npm install @evanion/nestjs-correlation-id

How to use

Add the middleware to your AppModule

import { MiddlewareConsumer, Module, NestModule } from '@nestjs/common';
import {
  CorrelationIdMiddleware,
  CorrelationModule,
} from '@evanion/nestjs-correlation-id';

@Module({
  imports: [CorrelationModule.forRoot()],
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(CorrelationIdMiddleware).forRoutes('*');
  }
}

And then just inject the correlation middleware in your HttpService by calling the registerAsync method with the withCorrelation function.

import { HttpModule } from '@nestjs/axios';
import { withCorrelation } from '@evanion/nestjs-correlation-id';

@Module({
  imports: [HttpModule.registerAsync(withCorrelation())],
  controllers: [UsersController],
  providers: [UsersService],
})
export class UsersModule {}

You can now use the HttpService as usual in your UsersService and UsersController

Customize

You can easily customize the header and ID by including a config when you register the module

@Module({
  imports: [CorrelationModule.forRoot({
    header: string
    generator: () => string
  })]
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(CorrelationIdMiddleware).forRoutes('*');
  }
}

Add correlationId to logs

In order to add the correlation ID to your logs, you can use the CorrelationService service to get the current correlationId.

In the following example, we are using the @ntegral/nestjs-sentry package, but you can use any package or provider you like.

import { CorrelationService } from '@evanion/nestjs-correlation-id';
import { Injectable, NestMiddleware } from '@nestjs/common';
import { InjectSentry, SentryService } from '@ntegral/nestjs-sentry';
import { NextFunction, Request, Response } from 'express';

@Injectable()
export class SentryMiddleware implements NestMiddleware {
  constructor(
    private readonly correlationService: CorrelationService,
    @InjectSentry() private readonly sentryService: SentryService,
  ) {}

  async use(_req: Request, _res: Response, next: NextFunction) {
    const correlationId = await this.correlationService.getCorrelationId();
    this.sentryService.instance().configureScope((scope) => {
      scope.setTag('correlationId', correlationId);
    });
    next();
  }
}

Then add it to your AppModule

import { Module } from '@nestjs-common';
import { SentryModule } from '@ntegral/nestjs-sentry';
import { CorrelationModule } from '@evanion/nestjs-correlation-id';
import { SentryMiddleware } from './middleware/sentry.middleware';

@Module({
  imports: [
    CorrelationModule.forRoot(),
    SentryModule.forRoot({
      // ... your config
    }),
  ],
})
export class AppModule implements NestModule {
  configure(consumer: MiddlewareConsumer) {
    consumer.apply(CorrelationIdMiddleware).forRoutes('*');
    consumer.apply(SentryMiddleware).forRoutes('*');
  }
}

If you need to manually set the correlationId anywhere in your application. You can use the CorrelationService service to set the correlationId.

this.correlationService.setCorrelationId('some_correlation_id');

see e2e tests for a fully working example

Change Log

See Changelog for more information.

Contributing

Contributions welcome! See Contributing.

Author

Mikael Pettersson (Evanion on Discord)

License

Licensed under the MIT License - see the LICENSE file for details.