@nestingjs/logger

Logger for Nest.js built on top of pino.

Installation

npm i @nestingjs/logger

Levels

This module has pre-defined levels for Nest.js.

customLevels: {
  verbose: 10,
  debug: 20,
  log: 30,
  warn: 40,
  error: 50,
  fatal: 60,
},

Usage

Import LoggerModule using either the forRoot or forRootAsync method in your application module.

import { LoggerModule } from '@nestingjs/logger';
import { Module } from '@nestjs/common';

@Module({
  imports: [
    LoggerModule.forRoot({
      level: 'verbose',
    }),
  ],
})
export class AppModule {}

In bootstrap function use logger.

[!NOTE]
Read about bufferLogs here

import { LoggerService } from '@nestingjs/logger';
import { NestFactory } from '@nestjs/core';

import { AppModule } from './app.module';

async function bootstrap() {
  const app = await NestFactory.create(AppModule, { bufferLogs: true });

  const logger = app.get(LoggerService);
  app.useLogger(logger);

  ...

  await app.listen(8080);
}

void bootstrap();

In any Injectable use logger from @nestjs/common. Under the hood it will log all messages using this logger.

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

@Controller()
export class AppHttpController {
  // This is the recomended way to use Logger by Nest.js
  private readonly logger = new Logger(AppHttpController.name);

  @Get('/')
  get() {
    this.logger.log('handled HTTP get route');
  }
}

Options

LoggerModuleOptions extends the pino.LoggerOptions except customLevels and useOnlyCustomLevels

export type LoggerModuleOptions = {
  /**
   * One of the supported levels ["verbose", "debug", "log", "warn", "error", "fatal"]
   * @default log
   */
  level?: LogLevel;
  /**
   * The string key for the Context in the JSON object.
   * @default context
   */
  contextKey?: string;

  /**
   * The string key for the Tracing ID in the JSON object.
   * @default trace
   */
  traceKey?: string;
} & Omit<pino.LoggerOptions<LogLevel, true>, 'customLevels' | 'useOnlyCustomLevels'>;

Pretty print

You can use @nestingjs/logger-pretty for pretty printing or use pino-pretty as your own.

Tracing

This logger has support tracing via @nestingjs/tracer