Unable to inject winston's logger instance with NestJS

Question

I'm using NestJS 7.0.7 and Winston 3.2.1 (with nest-winston 1.3.3).

I'm trying to integrate Winston into NestJS, but so far, I'm unable to inject a logger instance (to actually log anything) into any controller/service.

Since I would like to use Winston across the application AND during bootstrapping, I'm using the approach as the main Nest logger:

// main.ts
import { NestFactory } from "@nestjs/core";
import { WinstonModule } from "nest-winston";
import { format, transports } from "winston";
import { AppModule } from "./app.module";

async function bootstrap(): Promise<void> {
  const app = await NestFactory.create(AppModule, {
    logger: WinstonModule.createLogger({
      exitOnError: false,
      format: format.combine(format.colorize(), format.timestamp(), format.printf(msg => {
        return `${msg.timestamp} [${msg.level}] - ${msg.message}`;
      })),
      transports: [new transports.Console({ level: "debug" })], // alert > error > warning > notice > info > debug
    }),
  });
  app.use(helmet());
  await app.listen(process.env.PORT || 3_000);
}

bootstrap().then(() => {
  // ...
});

I'm not doing anything in regard to the logging in app.module.ts:

// app.module.ts
import { SomeController } from "@controller/some.controller";
import { Module } from "@nestjs/common";
import { SomeService } from "@service/some.service";

@Module({
  controllers: [SomeController],
  imports: [],
  providers: [SomeService],
})
export class AppModule {
  // ...
}

// some.controller.ts
import { Controller, Get, Inject, Param, ParseUUIDPipe, Post } from "@nestjs/common";
import { SomeService } from "@service/some.service";
import { WINSTON_MODULE_PROVIDER } from "nest-winston";
import { Logger } from "winston";

@Controller("/api/some-path")
export class SomeController {
  constructor(@Inject(WINSTON_MODULE_PROVIDER) private readonly logger: Logger, private readonly service: SomeService) {
    // ...
  }

  ...
}

The application tries to start but fails at some point:

2020-04-06T18:51:08.779Z [info] - Starting Nest application...
2020-04-06T18:51:08.787Z [error] - Nest can't resolve dependencies of the SomeController (?, SomeService). Please make sure that the argument winston at index [0] is available in the AppModule context.

Potential solutions:
- If winston is a provider, is it part of the current AppModule?
- If winston is exported from a separate @Module, is that module imported within AppModule?
  @Module({
    imports: [ /* the Module containing winston */ ]
  })

Answer 1

Try importing the WinstonModule in the root AppModule, as explained in the official docs: https://github.com/gremo/nest-winston:

import { Module } from '@nestjs/common';
import { WinstonModule } from 'nest-winston';
import * as winston from 'winston';

const logger: LoggerConfig = new LoggerConfig();    

@Module({
  imports: [WinstonModule.forRoot(logger.console())],
})
export class AppModule {}

It's probably a good idea to create some kind of factory/Logging-Config in order not to have to duplicate the logger options.

import winston, { format, transports } from "winston";

export class LoggerConfig {
  private readonly options: winston.LoggerOptions;

  constructor() {
    this.options = {
      exitOnError: false,
      format: format.combine(format.colorize(), format.timestamp(), format.printf(msg => {
        return `${msg.timestamp} [${msg.level}] - ${msg.message}`;
      })),
      transports: [new transports.Console({ level: "debug" })], // alert > error > warning > notice > info > debug
    };
  }

  public console(): object {
    return this.options;
  }
}

Answer 2

Implement Winston custom logger in NestJs project

Prerequisit:

npm install --save nest-winston winston winston-daily-rotate-file

import { NestFactory } from '@nestjs/core';
import { WinstonModule } from 'nest-winston';
import * as winston from 'winston';
import * as winstonDailyRotateFile from 'winston-daily-rotate-file';

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

const transports = {
  console: new winston.transports.Console({
    level: 'silly',
    format: winston.format.combine(
      winston.format.timestamp({
        format: 'YYYY-MM-DD HH:mm:ss',
      }),
      winston.format.colorize({
        colors: {
          info: 'blue',
          debug: 'yellow',
          error: 'red',
        },
      }),
      winston.format.printf((info) => {
        return `${info.timestamp} [${info.level}] [${
          info.context ? info.context : info.stack
        }] ${info.message}`;
      }),
      // winston.format.align(),
    ),
  }),
  combinedFile: new winstonDailyRotateFile({
    dirname: 'logs',
    filename: 'combined',
    extension: '.log',
    level: 'info',
  }),
  errorFile: new winstonDailyRotateFile({
    dirname: 'logs',
    filename: 'error',
    extension: '.log',
    level: 'error',
  }),
};

async function bootstrap() {
  const app = await NestFactory.create(AppModule);
  app.useLogger(
    WinstonModule.createLogger({
      format: winston.format.combine(
        winston.format.timestamp({
          format: 'YYYY-MM-DD HH:mm:ss',
        }),
        winston.format.errors({ stack: true }),
        winston.format.splat(),
        winston.format.json(),
      ),
      transports: [
        transports.console,
        transports.combinedFile,
        transports.errorFile,
      ],
    }),
  );
  await app.listen(4000);
}
bootstrap();

NestJs Custom Logger

NestJs Winston NPM Documentation

Note Log Levels, file names, dateformat you may edit as per your requirement. Follow officials documentations with more option.