I'm new to web development, and I run into a strange error. I have a React/Django app which I'm trying to productionize with nginx and docker. Django runs on a postgres db, and nginx just reroutes port 80 to my react and django ports.

When I locally deploy the application using

npm run build
serve -s build

everything works as desired.

However, doing the same through Docker doesn't.

I have a Dockerfile building the react application:

FROM node:12.18.3-alpine3.9 as builder
WORKDIR /usr/src/app
COPY ./react-app/package.json .
RUN apk add --no-cache --virtual .gyp \
        python \
        make \
        g++ \
    && npm install \
    && apk del .gyp
COPY ./react-app .
RUN npm run build
FROM node:12.18.3-alpine3.9
WORKDIR /usr/src/app
RUN npm install -g serve
COPY --from=builder /usr/src/app/build ./build

Now when I use

docker-compose build
docker-compose up

I see that my Django, React, Postgres and nginx containers are all running, with nginx visible at port 80. When I open localhost in my browser, I see nginx is looking for some static react files in the right directory. However, the react files it is looking for have a different hash than the static files. The static files of both the nginx and react container are the same. So somehow, my asset-manifest.json contains the wrong filenames. Any idea what causes this is or how I can solve this?

Edit: Added docker-compose.yml:

version: "3.7"

services:
  django:
    build:
      context: ./backend
      dockerfile: Dockerfile
    volumes:
      - django_static_volume:/usr/src/app/static
    expose:
      - 8000
    env_file:
      - ./backend/.env
    command: gunicorn core.wsgi:application --bind 0.0.0.0:8000
    depends_on:
      - db
  db:
    image: postgres:12.0-alpine
    volumes:
      - postgres_data:/var/lib/postgresql/data/
    env_file:
      - ./postgres/.env
  react:
    build:
      context: ./frontend
      dockerfile: Dockerfile
    volumes:
      - react_static_volume:/usr/src/app/build/static
    expose:
      - 5000
    env_file:
      - .env
    command: serve -s build
    depends_on:
      - django
  nginx:
    restart: always
    build: ./nginx
    volumes:
      - django_static_volume:/usr/src/app/django_files/static
      - react_static_volume:/usr/src/app/react_files/static
    ports:
      - 80:80
    depends_on:
      - react

volumes:
  postgres_data:
  django_static_volume:
  react_static_volume:

Do you need to run React in a separate container? Is there any reason for doing this? (It might be)

In my approach, I'm building React static files in nginx Dockerfile, and copy them to /usr/share/nginx/html. Then nginx serves it at location /.

nginx Dockerfile

# The first stage
# Build React static files
FROM node:13.12.0-alpine as build

WORKDIR /app/frontend
COPY ./frontend/package.json ./
COPY ./frontend/package-lock.json ./
RUN npm ci --silent
COPY ./frontend/ ./
RUN npm run build

# The second stage
# Copy React static files and start nginx
FROM nginx:stable-alpine
COPY --from=build /app/frontend/build /usr/share/nginx/html
CMD ["nginx", "-g", "daemon off;"]

nginx configuration file

server {
    listen 80;
    server_name _;
    server_tokens off;
    client_max_body_size 20M;

    location / {
        root   /usr/share/nginx/html;
        index  index.html index.htm;
        try_files $uri $uri/ /index.html;
    }

    location /api {
        try_files $uri @proxy_api;
    }
    location /admin {
        try_files $uri @proxy_api;
    }

    location @proxy_api {
        proxy_set_header X-Forwarded-Proto https;
        proxy_set_header X-Url-Scheme $scheme;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $http_host;
        proxy_redirect off;
        proxy_pass   http://backend:8000;
    }

    location /django_static/ {
        autoindex on;
        alias /app/backend/server/django_static/;
    }
}

Docker-compose

version: '2'

services:
    nginx: 
        restart: unless-stopped
        build:
            context: .
            dockerfile: ./docker/nginx/Dockerfile
        ports:
            - 80:80
        volumes:
            - static_volume:/app/backend/server/django_static
            - ./docker/nginx/development:/etc/nginx/conf.d
        depends_on: 
            - backend
    backend:
        restart: unless-stopped
        build:
            context: .
            dockerfile: ./docker/backend/Dockerfile
        volumes:
            
        entrypoint: /app/docker/backend/wsgi-entrypoint.sh
        volumes:
            - static_volume:/app/backend/server/django_static
        expose:
            - 8000        

volumes:
    static_volume: {}

Please check my article Docker-Compose for Django and React with Nginx reverse-proxy and Let's encrypt certificate for more details. There is also example of how to issue Let's encrypt certificate and renew it in docker-compose. If you will need more help, please let me know.