Can't access to the container even if it is running

I have a Flask API in a docker container. It interacts with other containers so I put everything in a docker-compose.
When I run docker-compose up the containers are successfully built and run, but I am not able to access to my API, neither from the browser nor with Python's requests module.

I will now paste here the Dockerfile with the configuration for the API's container:

FROM python:3.8.16-bullseye
RUN apt-get update
COPY requirements.txt requirements.txt
RUN pip install --upgrade pip && pip install -r requirements.txt
RUN mkdir "jobs"
COPY . /counter_sairus
WORKDIR /counter_sairus
EXPOSE 5000
ENTRYPOINT ["python", "api.py"]

And this is the docker-compose.yml:

version: "2.3"

services:
    api:
        container_name: api
        build:
            context: .
            dockerfile: Dockerfile
        environment:
            - BROKER_URI=redis://redis
            - BACKEND_URI=redis://redislistening on
        depends_on:
            - worker
            - redis
        volumes:
            -   ./jobs:/counter_sairus/jobs
    worker:
        container_name: celery
        environment:
            - BROKER_URI=redis://redis
            - BACKEND_URI=redis://redis
        build:
            context: .
            dockerfile: Dockerfile_worker
        depends_on:
            - redis
        volumes:
            -  ./jobs:/counter_sairus/jobs
    redis:
        image: "redis:alpine3.17"
        ports:
            - 6379

networks:
    default:
        external:
            name: rete1

Lastly, this is the doce in api.py :

api = Api(title="API", version="0.1", description="API")
application = Flask(__name__)
api.init_app(application)

if __name__ == '__main__':
    application.run(host='0.0.0.0', port=5000, debug=True)

After running the docker-compose, some log messages appear. Three of them come from the API container and are the following:

* Running on all addresses (0.0.0.0)
* Running on http://127.0.0.1:5000
* Running on http://172.18.0.9:5000

But, as I said, neither one of the two addresses work. If I try to reach them from the browser, in both the cases I get an error saying that the page cannot be reached.
I am running this on windows. But if I run the very same code on Ubuntu, the very same logs will appear (only the IP addresses change), and everything works well. I have no idea on how to solve this, any help would be much appreciated

Everything is contained by default in a container. So if you want to anything to be accessible such as a port, you need to be explicit about it.

docker-compose is basically just a more structured way for you to run docker commands. Now if you think about your containers and how you run them, like that, you can translate each into a docker run (and a build if you specify a dockerfile instead of anb image) command. For example your api:

docker build -t something . && docker run -d --rm celery -e ROKER_URI=redis://redis something

That's a little shortened, for readability.

So if you want to expose a port to be available, you'd need to tell that in the command in some way. There are multiple options, one is to expose a port. Which you would do like

docker run -p 5000:5000 celery something:latest

You will have to do the same in your compose file. (Note that there's a bit of a difference in compose between expose and port where one exposes ports to other compose services and the other publishes them to the host machine).

So you need to adapt your compose file like so:

version: "2.3"

services:
    api:
        container_name: api
        build:
            context: .
            dockerfile: Dockerfile
        environment:
            - BROKER_URI=redis://redis
            - BACKEND_URI=redis://redislistening on
        depends_on:
            - worker
            - redis
        volumes:
            -   ./jobs:/counter_sairus/jobs
    ports:
      - 5000:5000 
    worker:
        container_name: celery
        environment:
            - BROKER_URI=redis://redis
            - BACKEND_URI=redis://redis
        build:
            context: .
            dockerfile: Dockerfile_worker
        depends_on:
            - redis
        volumes:
            -  ./jobs:/counter_sairus/jobs
    ports:
      - 5000:5000 
    redis:
        image: "redis:alpine3.17"
        ports:
            - 6379

networks:
    default:
        external:
            name: rete1

Which is what you had done for the redis service already as well.