Docker不复制文件

我目前正在使用FE上的ReactJS、后端的Express和docker构建一个应用程序。我遇到一个问题,在docker中找不到我的节点服务器的my package.json。错误消息如下所示:

server_1    | [0] 
server_1    | [0] > stocklookback@1.0.0 server /code/app/server
server_1    | [0] > nodemon index.js
server_1    | [0] 
server_1    | [1] npm ERR! path /code/app/client/package.json
server_1    | [1] npm ERR! code ENOENT
server_1    | [1] npm ERR! errno -2
server_1    | [1] npm ERR! syscall open
server_1    | [1] npm ERR! enoent ENOENT: no such file or directory, open '/code/app/client/package.json'
server_1    | [1] npm ERR! enoent This is related to npm not being able to find a file.
server_1    | [1] npm ERR! enoent 
server_1    | [1] 
server_1    | [1] npm ERR! A complete log of this run can be found in:
server_1    | [1] npm ERR!     /root/.npm/_logs/2019-08-04T20_53_24_266Z-debug.log
server_1    | [1] npm ERR! code ELIFECYCLE
server_1    | [1] npm ERR! errno 254
server_1    | [1] npm ERR! stocklookback@1.0.0 client: `npm start --prefix ../client`
server_1    | npm ERR! Exit status 254
server_1    | [1] npm ERR! 
server_1    | [1] npm ERR! Failed at the stocklookback@1.0.0 client script.
server_1    | [1] npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
server_1    | [1] 
stocklookback_client_1 exited with code 1

现在,我的docker-compose.yml文件如下所示:

version: '3.3'

volumes:
  postgres_database :
     external: false

services:
 server:
   build: ./server
   expose:
     - ${APP_SERVER_PORT}
   environment:
     API_HOST: ${API_HOST}
     APP_SERVER_PORT: ${APP_SERVER_PORT}
   ports:
     - ${APP_SERVER_PORT}:${APP_SERVER_PORT}
   volumes:
     - ./server:/code/app/server/src
   command: npm run dev

FROM node:12.2.0-alpine

RUN mkdir -p /code/app/server/
WORKDIR /code/app/server/

COPY package.json /code/app/server/
COPY package-lock.json /code/app/server/

RUN npm install

COPY . /code/app/server/

CMD [ "npm", "start", "dev" ]

你知道我为什么会犯这个错误吗?