使用 Winston 实现分级日志收集

日志库的必要性

传输通道
- Console 文件
- File 文件
- Http 通过http传输
- Stream 流传输
格式化
- 时间戳
- 格式美化
日志分割
- 按文件大小分割
- 按写入时间分割
日志分级
- DEBUG：调试，等级最低，一般生产环境会将该等级的日志关闭
- INFO：信息，普通等级，最常用的系统日志收集等级，一般会将系统运行中的一些相关信息（非开发类敏感信息）设为该等级
- WARN：FBI WARNNING大家都知道，就是警告，但又不到错误
- ERROR：报错，一般程序报错使用该等级
- FATAL：严重，比程序报错还严重的等级，如果没做错误等级划分的话，一般FATAL都不怎么用到，都用ERROR替代了

src/shared/logger.service.ts

import { Injectable, Scope } from '@nestjs/common';
import { createLogger, Logger, transports, format } from 'winston';

@Injectable({ scope: Scope.TRANSIENT })
export class AppLogger {
  private context?: string;
  private logger: Logger;

  public setContext(context: string): void {
    this.context = context;
  }

  constructor() {
    this.logger = createLogger({
      level: 'info',
      format: format.combine(
        format.timestamp(),
        format.prettyPrint(),
      ),

      transports: [
        new transports.Console(),
        new transports.File({ filename: 'logs/error.log', level: 'error' }),
        new transports.File({ filename: 'logs/combined.log' }),
      ],
    });
  }

  error(
    ctx: any,
    message: string,
    meta?: Record<string, any>,
  ): Logger {

    return this.logger.error({
      message,
      contextName: this.context,
      ctx,
      ...meta,
    });
  }

  warn(
    ctx: any,
    message: string,
    meta?: Record<string, any>,
  ): Logger {
    return this.logger.warn({
      message,
      contextName: this.context,
      ctx,
      ...meta,
    });
  }

  debug(
    ctx: any,
    message: string,
    meta?: Record<string, any>,
  ): Logger {

    return this.logger.debug({
      message,
      contextName: this.context,
      ctx,
      ...meta,
    });
  }

  verbose(
    ctx: any,
    message: string,
    meta?: Record<string, any>,
  ): Logger {
    return this.logger.verbose({
      message,
      contextName: this.context,
      ctx,
      ...meta,
    });
  }

  log(
    ctx: any,
    message: string,
    meta?: Record<string, any>,
  ): Logger {
    return this.logger.info({
      message,
      contextName: this.context,
      ctx,
      ...meta,
    });
  }
}

/src/shared/logger/logger.module.ts
import { Module } from '@nestjs/common';

import { AppLogger } from './logger.service';

@Module({
  imports: [],
  providers: [AppLogger],
  exports: [AppLogger],
})
export class AppLoggerModule { }

src/shared/logger.service.ts
@Module({
  imports: [
    AppLoggerModule,
  ],
  exports: [
    AppLoggerModule,
  ],
})
export class SharedModule { }

测试

src/user/services/auth.services.ts
@Injectable()
export class AuthService {

  constructor(
    private readonly logger: AppLogger,
  ){
    this.logger.setContext(AuthService.name);
  }
  
  /**
   * 获取短信验证码
   * @param mobile 
   */
  async login(dto: RegisterCodeDTO) {
      this.logger.log(null, 'Login...')
  }
  
}

日志库的必要性​

测试​

日志库的必要性

测试