@homeofthings/nestjs-logger

HomeOfThings - Logger for NestJs

a logging module for NestJS based on winston which provides a reasonable configured logger for the application-wide use by all the NestJs loggers.

installation

npm install @homeofthings/nestjs-logger

quick start

import module in AppModule by providing options synchronously

@Module({
  imports: [
    LoggerModule.forRoot(LoggerModule, {
      // provide your options
    }),
  ],
})
export class AppModule {}

and set the injected LoggerService as the application logger:

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useLogger(app.get(LoggerService));
}
bootstrap();

import module in AppModule by providing options asynchronously

@Module({
  imports: [
    LoggerModule.forRootAsync(LoggerModule, {
      imports: [], // optional
      useFactory: (): Promise<LoggerModuleOptions> => Promise.resolve({
        // provide your options
      }),
      inject: [], // optional inject params for useFactory method
    }),
  ],
})
export class AppModule {}

and set the injected LoggerService as the application logger:

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useLogger(app.get(LoggerService));
}
bootstrap();

using as Nest Logger and for bootstrapping

const logger = LoggerModule.createLoggerService({
      // provide your options
    });
async function bootstrap() {
  const app = await NestFactory.create(AppModule, {loggger});
}
bootstrap();

NOTE: using this method, there is probably no need for additional imports of the LoggerModule in AppModule or any child module, but anyway if you decide to do so, only the options given to the first method will be taken into account

application logging

as recommended by nestjs:

import { Logger, Injectable } from '@nestjs/common';

@Injectable()
class MyService {
  private readonly logger = new Logger(MyService.name);
  
  doSomething() {
    this.logger.log('Doing something...');
  }
}

That way, the calls to this.logger.log() from MyService would result in calls to the method log from our logger instance.

environment variables

• FORCE_COLORS ... force color output
• NO_COLORS ... disable color output

default formatters

console

22:07:22.698 debug:   [Logger] Logger initialized
22:07:22.914 info:    [NestFactory] Starting Nest application...
22:07:22.932 debug:   [AppModule] AppModule created
22:07:22.934 info:    [InstanceLoader] AppModule dependencies initialized
22:07:22.937 debug:   [Application] Application created
22:07:22.937 debug:   [Application] Configuration:
22:07:22.938 debug:   [Application]   environment: development
22:07:22.938 debug:   [Application]   directory: /home/gms/work/HOT/HomeOfThings/workspace/config
22:07:22.943 info:    [RoutesResolver] AppController {/api}:
22:07:22.947 info:    [RouterExplorer] Mapped {/api, GET} route
22:07:22.950 info:    [NestApplication] Nest application successfully started
22:07:22.958 info:    [Application] Listening on http://localhost:8080/api

file

2021-04-11T19:58:57.602Z debug:   [Logger] Logger initialized
2021-04-11T19:58:57.812Z info:    [NestFactory] Starting Nest application...
2021-04-11T19:58:57.835Z debug:   [AppModule] AppModule created
2021-04-11T19:58:57.837Z info:    [InstanceLoader] AppModule dependencies initialized
2021-04-11T19:58:57.839Z debug:   [Application] Application created
2021-04-11T19:58:57.840Z debug:   [Application] Configuration:
2021-04-11T19:58:57.841Z debug:   [Application]   environment: development
2021-04-11T19:58:57.841Z debug:   [Application]   directory: /home/gms/work/HOT/HomeOfThings/workspace/config
2021-04-11T19:58:57.847Z info:    [RoutesResolver] AppController {/api}:
2021-04-11T19:58:57.852Z info:    [RouterExplorer] Mapped {/api, GET} route
2021-04-11T19:58:57.855Z info:    [NestApplication] Nest application successfully started
2021-04-11T19:58:57.862Z info:    [Application] Listening on http://localhost:8080/api