Angular 客户端应用程序无法从停靠容器解析后端服务的地址

我正在try 使用 docker 容器运行角形前端和Golang后端应用程序 它们已成功创建，但当前端try 对后端服务进行任何http调用时，都会失败

获取http://backend:8080/questions net::ERR_NAME_NOT_RESOLVED

通过判断，可以看出前端应用程序正在请求 请求URL: http://backend:8080/questions 推荐人政策: 交叉原点时严格原点

version: "3.8"
services:
  frontend:
    build: ./question-paper
    ports:
      - "4200:4200"

  backend:
    build: ./backend
    ports:
      - "8080:8080"
    environment:
      - DB_NAME=questions
      - DB_PORT=3306
      - DB_HOST=database
      - DB_PASSWD=root
      - DB_USER=root
    depends_on:
      - database

  database:
    image: mysql
    restart: always
    environment:
      MYSQL_DATABASE: questions
      MYSQL_PASSWORD: root
      MYSQL_ROOT_PASSWORD: root
    ports:
      - "3806:3306"
    volumes:
      - ./init.sql:/docker-entrypoint-initdb.d/  # Check the path to init.sql
      - my-db:/var/lib/mysql

volumes:
  my-db:

和我的Angular 代码

import { HttpClient } from '@angular/common/http';
import { Questions } from '../model/question-model';
import { Observable } from 'rxjs';
import { Inject, Injectable } from '@angular/core';


@Injectable({
  providedIn: 'root',
})
export class QuestionService {
  constructor(private httpClient: HttpClient) {}

  GetQuestions(): any {
    return this.httpClient.get('http://backend:8080/questions');
  }
}

后端代码

func main(){
    mux := mux.NewRouter()
    handle := h.CORS(
        h.AllowedOrigins([]string{"*"}),
        h.AllowedMethods([]string{"GET", "POST", "PUT", "DELETE", "HEAD", "OPTIONS"}),
        h.AllowedHeaders([]string{"Content-Type", "Authorization", "Origin", "Accept"}),
    )
    mux.HandleFunc("/questions", handlers.GetQuestions)
    http.ListenAndServe(":8080", handle(mux))
}

error个

有人能帮我解释一下请求失败的原因吗， 我可以考虑一些解决方案，比如在http url中使用后端服务的IP地址，我认为这不是一个好的 Select