I have a postgresql, and a redis server.

my django application needs to wait for them all completed to run.

BTW, postgresql, redis, django all run in Docker containers . Here 3 containers .

so, use dockerize in my main django Dockerfile

# install dockerize
RUN apt-get update && apt-get install -y wget
ENV DOCKERIZE_VERSION v0.6.1
RUN wget https://github.com/jwilder/dockerize/releases/download/$DOCKERIZE_VERSION/dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
    && tar -C /usr/local/bin -xzvf dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz \
    && rm dockerize-linux-amd64-$DOCKERIZE_VERSION.tar.gz

in my docker-compose.yml

  web:
    build: .
    # wait for postgresql, redis server up using dockerize
    command: 
            dockerize -wait tcp://redis-cache:6379 -timeout 30s \
            dockerize -wait tcp://db:5432 -timeout 30s \
            python3 manage.py runserver 0.0.0.0:8000

tcp://redis-cache:6379 // my redis server

tcp://db:5432 // my postgresql database server

after all tcp ports okay, run the commands

python3 manage.py runserver 0.0.0.0:8000