环境准备

搭建elk环境，自行搭建，本篇主要集中 log4js的配置

集成第三方库

yarn add log4js @log4js-node/logstash-http

编写logconfig

创建/config/log4js.ts文件

import * as path from 'path';

const log4jsConfig = {
  appenders: {
    /** logstash 配置 */
    logstash: {
      type: '@log4js-node/logstash-http',
      url: 'http://192.168.56.10:9200/_bulk',
      application: 'nest-admin',
      logType: 'application',
      logChannel: 'node',
    },
    console: {
      type: 'console', // 会打印到控制台
    },
    access: {
      type: '@log4js-node/logstash-http',
      url: 'http://192.168.56.10:9200/_bulk',
      application: 'nest-admin-access',
      logType: 'access',
      logChannel: 'node',
    },
    app: {
      type: '@log4js-node/logstash-http',
      url: 'http://192.168.56.10:9200/_bulk',
      application: 'nest-admin-app',
      logType: 'app',
      logChannel: 'node',
    },
    errors: {
      type: '@log4js-node/logstash-http',
      url: 'http://192.168.56.10:9200/_bulk',
      application: 'nest-admin',
      logType: 'errors',
      logChannel: 'node',
    },
  },
  categories: {
    default: {
      appenders: ['app', 'errors', 'logstash'],
      level: 'DEBUG',
    },
    info: { appenders: ['app', 'errors', 'logstash'], level: 'info' },
    access: { appenders: ['app', 'errors', 'logstash'], level: 'info' },
    http: { appenders: ['access', 'logstash'], level: 'DEBUG' },
  },
  pm2: true, // 使用 pm2 来管理项目时，打开
  pm2InstanceVar: 'INSTANCE_ID', // 会根据 pm2 分配的 id 进行区分，以免各进程在写日志时造成冲突
};

export default log4jsConfig;

application对应elk中生成的index pattern
logType 对应日志类型
url对应 elasticsearch地址

log4js.ts 文件编写log工具类

创建utils/log4js.ts文件

import * as Path from 'path';
import * as Log4js from 'log4js';
import * as Util from 'util';
import * as Moment from 'moment'; // 处理时间的工具
import * as StackTrace from 'stacktrace-js';
import Chalk from 'chalk';
import config from '../config/log4js';

// 日志级别
export enum LoggerLevel {
  ALL = 'ALL',
  MARK = 'MARK',
  TRACE = 'TRACE',
  DEBUG = 'DEBUG',
  INFO = 'INFO',
  WARN = 'WARN',
  ERROR = 'ERROR',
  FATAL = 'FATAL',
  OFF = 'OFF',
}

// 内容跟踪类
export class ContextTrace {
  constructor(
    public readonly context: string,
    public readonly path?: string,
    public readonly lineNumber?: number,
    public readonly columnNumber?: number,
  ) {}
}

Log4js.addLayout('Awesome-nest', (logConfig: any) => {
  return (logEvent: Log4js.LoggingEvent): string => {
    let moduleName = '';
    let position = '';

    // 日志组装
    const messageList: string[] = [];
    logEvent.data.forEach((value: any) => {
      if (value instanceof ContextTrace) {
        moduleName = value.context;
        // 显示触发日志的坐标（行，列）
        if (value.lineNumber && value.columnNumber) {
          position = `${value.lineNumber}, ${value.columnNumber}`;
        }
        return;
      }

      if (typeof value !== 'string') {
        value = Util.inspect(value, false, 3, true);
      }

      messageList.push(value);
    });

    // 日志组成部分
    const messageOutput: string = messageList.join(' ');
    const positionOutput: string = position ? ` [${position}]` : '';
    const typeOutput = `[${logConfig.type}] ${logEvent.pid.toString()}   - `;
    const dateOutput = `${Moment(logEvent.startTime).format(
      'YYYY-MM-DD HH:mm:ss',
    )}`;
    const moduleOutput: string = moduleName
      ? `[${moduleName}] `
      : '[LoggerService] ';
    let levelOutput = `[${logEvent.level}] ${messageOutput}`;

    // 根据日志级别，用不同颜色区分
    switch (logEvent.level.toString()) {
      case LoggerLevel.DEBUG:
        levelOutput = Chalk.green(levelOutput);
        break;
      case LoggerLevel.INFO:
        levelOutput = Chalk.cyan(levelOutput);
        break;
      case LoggerLevel.WARN:
        levelOutput = Chalk.yellow(levelOutput);
        break;
      case LoggerLevel.ERROR:
        levelOutput = Chalk.red(levelOutput);
        break;
      case LoggerLevel.FATAL:
        levelOutput = Chalk.hex('#DD4C35')(levelOutput);
        break;
      default:
        levelOutput = Chalk.grey(levelOutput);
        break;
    }

    return `${Chalk.green(typeOutput)}${dateOutput}  ${Chalk.yellow(
      moduleOutput,
    )}${levelOutput}${positionOutput}`;
  };
});

// 注入配置
Log4js.configure(config);

// 实例化
const logger = Log4js.getLogger();
logger.level = LoggerLevel.TRACE;

export class Logger {
  static trace(...args) {
    logger.trace(Logger.getStackTrace(), ...args);
  }

  static debug(...args) {
    logger.debug(Logger.getStackTrace(), ...args);
  }

  static log(...args) {
    logger.info(Logger.getStackTrace(), ...args);
  }

  static info(...args) {
    logger.info(Logger.getStackTrace(), ...args);
  }

  static warn(...args) {
    logger.warn(Logger.getStackTrace(), ...args);
  }

  static warning(...args) {
    logger.warn(Logger.getStackTrace(), ...args);
  }

  static error(...args) {
    logger.error(Logger.getStackTrace(), ...args);
  }

  static fatal(...args) {
    logger.fatal(Logger.getStackTrace(), ...args);
  }

  static access(...args) {
    const loggerCustom = Log4js.getLogger('http');
    loggerCustom.info(Logger.getStackTrace(), ...args);
  }

  // 日志追踪，可以追溯到哪个文件、第几行第几列
  static getStackTrace(deep = 2): string {
    const stackList: StackTrace.StackFrame[] = StackTrace.getSync();
    const stackInfo: StackTrace.StackFrame = stackList[deep];

    const lineNumber: number = stackInfo.lineNumber;
    const columnNumber: number = stackInfo.columnNumber;
    const fileName: string = stackInfo.fileName;
    const basename: string = Path.basename(fileName);
    return `${basename}(line: ${lineNumber}, column: ${columnNumber}): \n`;
  }
}

使用log4js

捕获全局异常

import {
  ExceptionFilter,
  Catch,
  ArgumentsHost,
  HttpException,
  HttpStatus,
} from '@nestjs/common';
import { Request, Response } from 'express';
import { Logger } from 'src/utils/log4js';

@Catch() // 捕获所有异常
export class AllExceptionsFilter implements ExceptionFilter<Error> {
  catch(exception: Error, host: ArgumentsHost) {
    const ctx = host.switchToHttp();
    const response = ctx.getResponse<Response>();
    const request = ctx.getRequest<Request>();
    const status =
      exception instanceof HttpException
        ? exception.getStatus()
        : HttpStatus.INTERNAL_SERVER_ERROR;
    // @todo 记录日志
    const logFormat = ` <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    Request original url: ${request.originalUrl}
    Method: ${request.method}
    IP: ${request.ip}
    Status code: ${status}
    Response: ${exception.toString()} \n  <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    `;
    Logger.error(logFormat);
    // 发送响应
    response.status(status).json({
      statusCode: status,
      error: exception.message,
      message: `${status >= 500 ? 'Service Error' : 'Client Error'}`,
      timestamp: new Date().toLocaleString(),
      path: request.url,
    });
  }
}

中间件

import { Request, Response } from 'express';
import { Logger } from '../utils/log4js';

// 函数式中间件
export function logger(req: Request, res: Response, next: () => any) {
  const code = res.statusCode; // 响应状态码
  next();
  // 组装日志信息
  const logFormat = ` >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
    请求参数
    Request original url: ${req.originalUrl}
    Method: ${req.method}
    IP: ${req.ip}
    Status code: ${code}
    Parmas: ${JSON.stringify(req.params)}
    Query: ${JSON.stringify(req.query)}
    Body: ${JSON.stringify(
      req.body,
    )} \n  >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
  `;
  // 根据状态码，进行日志类型区分
  if (code >= 500) {
    Logger.error(logFormat);
  } else if (code >= 400) {
    Logger.warn(logFormat);
  } else {
    Logger.access(logFormat);
    Logger.log(logFormat);
  }
}

拦截器

import {
  CallHandler,
  ExecutionContext,
  Injectable,
  NestInterceptor,
} from '@nestjs/common';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { Logger } from '../utils/log4js';

@Injectable()
export class TransformInterceptor implements NestInterceptor {
  intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
    const req = context.getArgByIndex(1).req;
    return next.handle().pipe(
      map((data) => {
        const logFormat = ` <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
    请求数据
    Request original url: ${req.originalUrl}
    Method: ${req.method}
    IP: ${req.ip}
    User: ${JSON.stringify(req.headers.user)}
    Response data:\n ${JSON.stringify(data.data)}
    <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<`;
        Logger.info(logFormat);
        Logger.access(logFormat);
        return data;
      }),
    );
  }
}

验证器

// src/pipe/validation.pipe.ts
import {
  ArgumentMetadata,
  Injectable,
  PipeTransform,
  BadRequestException,
} from '@nestjs/common';
import { validate } from 'class-validator';
import { plainToClass } from 'class-transformer';
import { Logger } from '../utils/log4js';

@Injectable()
export class MyValidationPipe implements PipeTransform {
  async transform(value: any, { metatype }: ArgumentMetadata) {
    if (!metatype || !this.toValidate(metatype)) {
      // 如果没有传入验证规则，则不验证，直接返回数据
      return value;
    }
    // 将对象转换为 Class 来验证
    const object = plainToClass(metatype, value);
    const errors = await validate(object);
    if (errors.length > 0) {
      const msg = Object.values(errors[0].constraints)[0]; // 只需要取第一个错误信息并返回即可
      Logger.error(`Validation failed: ${msg}`);
      throw new BadRequestException(`Validation failed: ${msg}`);
    }
    return value;
  }

  private toValidate(metatype: any): boolean {
    const types: any[] = [String, Boolean, Number, Array, Object];
    return !types.includes(metatype);
  }
}