实现 Nest.js 应用日志服务有很多选择，较为出名的有：Log4js、winston、Pino。
这次就以 winston 为例，记录一下如何实现 Nest.js 应用日志服务。本文参考了搜索引擎中许多教程与案例，如果觉得有任何问题可以留言与我交流。
引入 winston
相关依赖：winston、nest-winston、winston-daily-rotate-file
pnpm install winston nest-winston winston-daily-rotate-filewinston-daily-rotate-file 用于实现日志文件的定期归档。由于应用日志量一般都非常大，因此需要定期自动对日志文件进行轮换、归档与删除。
配置 winston
app.module.ts
import {
// ...
Module,
} from '@nestjs/common';
import { WinstonModule } from 'nest-winston';
import * as winston from 'winston';
import 'winston-daily-rotate-file';
// ...
@Module({
controllers: [],
imports: [
// ...
WinstonModule.forRoot({
transports: [
new winston.transports.DailyRotateFile({
dirname: `logs`, // 日志保存的目录
filename: '%DATE%.log', // 日志名称，占位符 %DATE% 取值为 datePattern 值。
datePattern: 'YYYY-MM-DD', // 日志轮换的频率，此处表示每天。
zippedArchive: true, // 是否通过压缩的方式归档被轮换的日志文件。
maxSize: '20m', // 设置日志文件的最大大小，m 表示 mb 。
maxFiles: '14d', // 保留日志文件的最大天数，此处表示自动删除超过 14 天的日志文件。
// 记录时添加时间戳信息
format: winston.format.combine(
winston.format.timestamp({
format: 'YYYY-MM-DD HH:mm:ss',
}),
winston.format.json(),
),
}),
],
}),
],
// ...
})
export class AppModule { // ... }在全局中间件、过滤器以及拦截器中记录日志
获取请求头信息的工具方法
getReqMainInfo.ts
import { Request } from 'express';
export const getReqMainInfo: (req: Request) => {
[prop: string]: any;
} = req => {
const { query, headers, url, method, body, connection } = req;
// 获取 IP
const xRealIp = headers['X-Real-IP'];
const xForwardedFor = headers['X-Forwarded-For'];
const { ip: cIp } = req;
const { remoteAddress } = connection || {};
const ip = xRealIp || xForwardedFor || cIp || remoteAddress;
return {
url,
host: headers.host,
ip,
method,
query,
body,
};
};
在全局中间件中记录日志
logger.middleware.ts
import { Inject, Injectable, NestMiddleware } from '@nestjs/common';
import { Request, Response, NextFunction } from 'express';
import { WINSTON_MODULE_PROVIDER } from 'nest-winston';
import { Logger } from 'winston';
import { getReqMainInfo } from '../../utils/getReqMainInfo';
@Injectable()
export default class LoggerMiddleware implements NestMiddleware {
// 注入日志服务相关依赖
constructor(
@Inject(WINSTON_MODULE_PROVIDER) private readonly logger: Logger,
) {}
use(req: Request, res: Response, next: NextFunction) {
// 获取请求信息
const {
query,
headers: { host },
url,
method,
body,
} = req;
// 记录日志
this.logger.info('route', {
req: getReqMainInfo(req),
});
next();
}
}
在全局异常过滤器中记录日志
uinify-exception.filter.ts
import {
ArgumentsHost,
Catch,
ExceptionFilter,
HttpException,
HttpStatus,
Inject,
} from '@nestjs/common';
import { Response, Request } from 'express';
import { WINSTON_MODULE_PROVIDER } from 'nest-winston';
import { Logger } from 'winston';
import { getReqMainInfo } from '../../utils/getReqMainInfo';
@Catch()
export default class UnifyExceptionFilter implements ExceptionFilter {
// 注入日志服务相关依赖
constructor(
@Inject(WINSTON_MODULE_PROVIDER) private readonly logger: Logger,
) {}
catch(exception: HttpException, host: ArgumentsHost) {
const ctx = host.switchToHttp(); // 获取当前执行上下文
const res = ctx.getResponse<Response>(); // 获取响应对象
const req = ctx.getRequest<Request>(); // 获取请求对象
const status =
exception instanceof HttpException
? exception.getStatus()
: HttpStatus.INTERNAL_SERVER_ERROR;
const response = exception.getResponse();
let msg =
exception.message || (status >= 500 ? 'Service Error' : 'Client Error');
if (Object.prototype.toString.call(response) === '[object Object]') {
if (typeof response === 'string') {
msg = response;
}
}
const { query, headers, url, method, body } = req;
// 记录日志（错误消息，错误码，请求信息等）
this.logger.error(msg, {
status,
req: getReqMainInfo(req),
// stack: exception.stack,
});
res.status(status >= 500 ? status : 200).json({ code: 1, msg });
}
}
在响应拦截器中记录日志
unify-response.interceptor.ts
import {
CallHandler,
ExecutionContext,
Inject,
Injectable,
NestInterceptor,
} from '@nestjs/common';
import { Observable } from 'rxjs';
import { map } from 'rxjs/operators';
import { Request } from 'express';
import { WINSTON_MODULE_PROVIDER } from 'nest-winston';
import { Logger } from 'winston';
import { getReqMainInfo } from '../../utils/getReqMainInfo';
@Injectable()
export class UnifyResponseInterceptor implements NestInterceptor {
constructor(
@Inject(WINSTON_MODULE_PROVIDER) private readonly logger: Logger,
) {}
intercept(context: ExecutionContext, next: CallHandler): Observable<any> {
const ctx = context.switchToHttp();
const req = ctx.getRequest<Request>();
return next.handle().pipe(
map(data => {
this.logger.info('response', {
responseData: data,
req: getReqMainInfo(req),
});
return {
code: 0,
data,
msg: '成功',
};
}),
);
}
}
应用全局中间件、过滤器以及拦截器
app.module.ts
import {
MiddlewareConsumer,
Module,
NestModule,
RequestMethod,
} from '@nestjs/common';
import { APP_FILTER } from '@nestjs/core';
import { WinstonModule } from 'nest-winston';
import * as winston from 'winston';
import 'winston-daily-rotate-file';
import UnifyExceptionFilter from './common/uinify-exception.filter';
import logger from './common/logger.middleware';
// ...
@Module({
// ...
imports: [
// ...
WinstonModule.forRoot({
// ...
}),
],
providers: [
// ...
// 应用全局过滤器
{
provide: APP_FILTER,
useClass: UnifyExceptionFilter,
},
// 应用拦截器
{
provide: APP_INTERCEPTOR,
useClass: UnifyResponseInterceptor,
},
],
})
export class AppModule implements NestModule {
// 应用全局中间件
configure(consumer: MiddlewareConsumer) {
consumer.apply(logger).forRoutes({ path: '*', method: RequestMethod.ALL });
}
}完成以上配置后，项目目录下就会包含访问及错误信息的日志文件。日志文件将每天自动归档压缩，超过 14 天的日志也将被自动删除。
引用
基于 Winston 实现 NestJS 应用日志服务
NestJS: Setting up file logging daily rotation with winston