encode/httpx#1025

docker-compose.yml

version: '3'
services:
    app:
        image: nginx
    not_in_list:
        image: nginx

    client:
        image: httpx_client
        build: .
        depends_on: [app]

Dockerfile

FROM python:3.8-slim
RUN pip install httpx
WORKDIR /code
ADD ./main.py /code/main.py
CMD python /code/main.py

main.py

import httpx, time

time.sleep(2)

response = httpx.get('http://not_in_list')
print(response.status_code)

response = httpx.get('http://app')
print(response.status_code)