`django_1 | no port[s] to connect to` When I try to run `docker-compose up`

I’m using Django and React to build a project. I currently can run each server separately (react and django), but I can’t run my docker-compose up command without getting an error that Django has no ports to connect to.

Django Dockerfile

 '###########

# BUILDER #

###########

# pull official base image

FROM python:3.7.9-slim-stretch as builder

# set work directory

WORKDIR /usr/src/app

# set environment variables

ENV PYTHONDONTWRITEBYTECODE 1

ENV PYTHONUNBUFFERED 1

# install dependencies

COPY ./requirements.txt .

RUN pip wheel --no-cache-dir --no-deps --wheel-dir /usr/src/app/wheels -r requirements.txt

#########

# FINAL #

#########

# pull official base image

FROM python:3.7.9-slim-stretch

# installing netcat (nc) since we are using that to listen to postgres server in entrypoint.sh

RUN apt-get update && apt-get install -y --no-install-recommends netcat && \

apt-get autoremove -y && \

apt-get clean && \

rm -rf /var/lib/apt/lists/*

# install dependencies

COPY --from=builder /usr/src/app/wheels /wheels

COPY --from=builder /usr/src/app/requirements.txt .

RUN pip install --no-cache /wheels/*

# set work directory

WORKDIR /usr/src/app

# copy entrypoint.sh

COPY ./entrypoint.sh /usr/src/app/entrypoint.sh

# copy our django project

COPY ./django_app .

# run entrypoint.sh

RUN chmod +x /usr/src/app/entrypoint.sh

=

ENTRYPOINT ["/usr/src/app/entrypoint.sh"] ```

React Dockerfile


###########
# BUILDER #
###########

# pull official base image
FROM node:12.18.3-alpine3.9 as builder

# set work directory
WORKDIR /usr/src/app

# install dependencies and avoid `node-gyp rebuild` errors
COPY ./react_app/package.json .
RUN apk add --no-cache --virtual .gyp \
        python \
        make \
        g++ \
    && npm install \
    && apk del .gyp

# copy our react project
COPY ./react_app .

# perform npm build
ARG API_SERVER
ENV REACT_APP_API_SERVER=${API_SERVER}
RUN REACT_APP_API_SERVER=${API_SERVER} \ 
  npm run build

#########
# FINAL #
#########

# pull official base image
FROM node:12.18.3-alpine3.9 

# set work directory
WORKDIR /usr/src/app

# install serve - deployment static server suggested by official create-react-app
RUN npm install -g serve

# copy our build files from our builder stage
COPY --from=builder /usr/src/app/build ./build

Nginx Dockerfile


FROM nginx:1.19.10-alpine

RUN rm /etc/nginx/conf.d/default.conf
COPY nginx.conf /etc/nginx/conf.d

WORKDIR /usr/src/app

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 candle.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
      args:
        - API_SERVER=${ENV_API_SERVER}
    volumes:
      - react_static_volume:/usr/src/app/build/static
    expose:
      - 3000
    env_file:
      - .env
    command: serve -s build -l 3000
    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: