无法在 docker-compose 文件中的容器之间共享卷

Question

I want to share the file build that is generated by my react container to my Nginx container.

react:
   stdin_open: true
   build:
     dockerfile: ./react.dockerfile
     context: ../frontend
   volumes:
     - /app/node_modules
     - files_built:/app/build
   networks:
     - default
 nginx:
    stdin_open: true
    build:
       dockerfile: ./nginx.dockerfile
       context: ../frontend
    volumes:
       - /app/node_modules
       - ../frontend/nginx:/config
       - files_built:/app/build
    networks:
       - default
    environment:
       - PUID=1000
       - PGID=1000
       - TZ=Europe/London
       - URL=myurl.com
       - VALIDATION=http
       - STAGING=true #optional
    ports:
       - 443:443
       - 80:80 #optional
    depends_on:
       - react
 volumes:
    public:
    db-data:
    files_built:
 networks:
    default:

When I go in the react container, the build file is in the folder /app. I am trying to use a named volume (files_build) in both the react and the Nginx containers. But with the code bellow, I cannot find any folder files_built in the VM or build file in the Nginx container (using the command find / -name "build").

What am I doing wrong?

Thanks for your help, Hugo

Answer 1

For a typical React application, you'll compile it down to static files and serve those static files; there's no specific need for a running server. You can use a multi-stage build for this. Your Dockerfile would look roughly like:

FROM node:lts AS build
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY ./ ./
RUN npm build

FROM nginx
COPY --from=build /app/dist /usr/share/nginx/html
# base image contains the right CMD already

That means you can remove the react container from your Compose setup and reduce the docker-compose.yml file to

version: '3.8'
services:
  nginx:
    build: ../frontend
    volumes:
       - ../frontend/nginx:/config
    environment:
       - TZ=Europe/London
       - URL=myurl.com
       - VALIDATION=http
       - STAGING=true #optional
    ports:
       - 443:443
       - 80:80 #optional

You do not need volumes: here. There are a couple of notable problems with using volumes: since their content never gets updated they are prone to overwriting your application with old content, and they do not translate well to clustered environments like Kubernetes. It's better to COPY content into Docker images than to try to share files between containers.