Waiting for a webserver container example

docker-compose.yml

version: '3'
networks:
  test_net:

services:
  webserver:
    image: nginx:alpine
    command: sh -c 'sleep 10 && nginx -g "daemon off;"'
    networks:
      - test_net

  test:
    image: alpine
    command:  sh -c 'while ! nc webserver 80; do echo '.' && sleep 1; done && echo "Webserver up and running, bye bye..!"'
    networks:
      - test_net