Having trouble communicating between docker-compose services

Question

I have the following docker-compose file:

version: \"3\"

services:
  scraper-api:
    build: ./ATPScraper
    volumes:
      - ./ATPScraper:/usr/sr         


        

Answer 1

As a side note: when no network is specified inside docker-compose.yml, default network will be created for you with the following name [dir location of docker_compose.yml]_default. For example, if docker_compose.yml is in app folder. the network will be named app_default.

Now, inside this network, containers are reachable by their service names. So scraper-api host should resolve to the right container.

It could be that you are using wrong endpoint URL. In the question, you mentioned /api/top_10 as an endpoint, but URL to test was http://scraper-api:80/api/test_api which is inconsistent.

Also, it could be that you confused the order of the ports in docker-compose.yml for scraper-api service:

ports:
   - "5000:80"

5000 is being exposed to host where docker is running. 80 is internal app port. Normally, flask apps are listening on 5000, so I thought you might have meant to say:

ports:
   - "80:5000"

In which case, between containers you have to use :5000 as destination port in URLs: http://scraper-api:5000 as an example (+ endpoint suffix, of course).

To check connectivity, you might want to bash into client container, and see if things are connecting:

docker-compose exec test-app bash
wget http://scraper-api
wget http://scraper-api:5000

etc.

If you get a response, then you have connectivity, just need to figure out correct endpoint URL.