Why ConnectionError using python in docker-compose?

Question

I have this

docker-compose:

version: '3.3'

services:
  bd_mySql:
    image: mysql:5.7     
    restart: always
    ports:
      - "3306:3306"
    environment:
      MYSQL_USER: razvan
      MYSQL_PASSWORD: PepitoElDeLosPalotes
      MYSQL_ROOT_PASSWORD: PepitoElDeLosPalotes
      MYSQL_DATABASE: equipojugadores
  api:
    build: data
    restart: always
    ports:
      - "8084:8084"
  python:
    build: python
    restart: on-failure
    depends_on: 
      - api      

dockerfile (python)

FROM python:latest

ADD scraper.py /

RUN pip install BeautifulSoup4
RUN pip install html5lib
RUN pip install requests
RUN pip install lxml

CMD [ "python", "scraper.py" ]

And i have this error:

requests.exceptions.ConnectionError: HTTPConnectionPool(host='localhost', port=8084):

why?

Answer 1

Your scraper.py code is trying to connect to localhost:8004 , however you have placed the service that advertises port 8004 on a separate container. This is similar to if you had placed it on a separate machine, and so localhost won't reach it. Instead, you have to use api:8004 , which will resolve to the IP of the api container, which is where you put this service.

Answer 2

Your py code is trying to connect with localhost for that you need provide links in python part.
After that you can call the request http://api:8084/apiname .
This worked for me:

api:
    build: data
    restart: always
    ports:
      - "8084:8084"
python:
    build: python
    restart: on-failure
    depends_on: 
      - api
    links:
      - api