在运行docker-compose时遇到此错误-TypeError：redis.createCient（{}）不是函数

Question

我写了这个脚本来统计每次访问的用户。 但是在构建过程中，它可以成功下载并安装依赖项 但是在使用命令 docker-compose up 执行时，redis.createClient（{}）行抛出了错误，提示它不是函数。

---

**#Dockerfile**
FROM node:alpine

WORKDIR /app

COPY package.json .

RUN npm install

COPY . .

CMD ["npm", "start"]

---

**#docker-compose.yml** 
version : '3'

services:
  redis-server:
    restart: always
    image: redis
  node-app:
    restart: on-failure
    build: .
    ports:
      - "4001:8081"

---

**# Application Code**

const express = require('express');
const redis = require('redis');
const process = require('process');

const app = express();
const client = redis.createClient({
    host: 'redis-server',
    port: 6379
});
client.set('visits', 0);

app.get('/', (req, res) => {
    client.get('visits', (err, visits) => {
        res.send('Number of visits ' + visits);
        client.set('visits', parseInt(visits) + 1);
    });
});

app.listen(8081, () => {
    console.log('Listening on port 8081');
});