technique_proxy/src/service/proxy.service.ts

import { Config, Inject, InjectClient, Provide } from '@midwayjs/core';
import { Context } from '@midwayjs/koa';
import { RequestBase } from '../interface/proxy.interface';
import { get, lowerCase, pick } from 'lodash';
import { HttpServiceFactory, HttpService } from '@midwayjs/axios';
import { Axios } from '@midwayjs/axios';
@Provide()
export class ProxyService {
  @Inject()
  ctx: Context;

  @Config('axios.clients')
  axiosClients: object;

  @InjectClient(HttpServiceFactory, 'default')
  serviceAxios: HttpService;

  @Inject()
  sf: HttpServiceFactory;

  getRequstBase(): RequestBase {
    const request = this.ctx.request;
    const result: RequestBase = pick(request, [
      'method',
      'header',
      'path',
      'query',
      'querystring',
      'body',
      'rawBody',
      'host',
      'ip',
      'originalUrl',
    ]) as RequestBase;

    return result;
  }

  async toProxy() {
    const rb: RequestBase = this.getRequstBase();
    // 解析路由前缀
    const uri = rb.originalUrl;
    const keys = Object.keys(this.axiosClients);
    let url;
    for (const prefix of keys) {
      const regRules = `^(${prefix})`;
      const reg = new RegExp(regRules);
      const res = reg.test(uri);
      if (!res) continue;
      const clientConfig = this.axiosClients[prefix];
      const baseURL = clientConfig.baseURL;
      // 去掉前缀
      // url = uri.replace(reg, baseURL);
      // 保留前缀(目前采用这一方式处理)
      url = `${baseURL}${rb.originalUrl}`;
      break;
    }
    if (!url) return;
    console.log(url);
    const reqConfig: any = {
      url,
      method: rb.method,
      headers: rb.header,
    };
    if (lowerCase(rb.method) === 'post') reqConfig.data = rb.body;
    const res = await this.serviceAxios.request(reqConfig);
    if (res.status !== 200) throw new Error('proxy service request error');
    return res.data;
  }

  async getAxios(clientConfig: object): Promise<Axios.AxiosInstance> {
    const rb: RequestBase = this.getRequstBase();
    const axi = await this.sf.createInstance({
      ...clientConfig,
      header: get(rb, 'header'),
    });
    return axi;
  }
}