Microservices FastAPI test in docker, return 404

I created a simple library project in microservices to study and implement FastAPI. Docker starts 5 main services:

• books
• db-book
• author
• db-author
• nginx

Everything works as expected, making requests with postman I have no problem.

Structure

Problem description

I added a test directory where I test endpoints.

Example of (incomplete) author test

from starlette.testclient import TestClient
from app.main import app
from app.api.author import authors
import logging
log = logging.getLogger('__name__')
import requests

client = TestClient(app)

def test_get_authors():
    response = client.get("/")
    assert response.status_code == 200

def test_get_author():
    response = client.get("/1")
    assert response.status_code == 200

$> docker-compose exec author_service pytest . returns this

============================================================================================================= test session starts =============================================================================================================
platform linux -- Python 3.8.3, pytest-5.3.2, py-1.9.0, pluggy-0.13.1
rootdir: /app
collected 2 items                                                                                                                                                                                                                             

tests/test_author.py FF                                                                                                                                                                                                                 [100%]

================================================================================================================== FAILURES ===================================================================================================================
______________________________________________________________________________________________________________ test_get_authors _______________________________________________________________________________________________________________

    def test_get_authors():
        response = client.get("/")
>       assert response.status_code == 200
E       assert 404 == 200
E        +  where 404 = <Response [404]>.status_code

tests/test_author.py:12: AssertionError
_______________________________________________________________________________________________________________ test_get_author _______________________________________________________________________________________________________________

    def test_get_author():
        response = client.get("/1")
>       assert response.status_code == 200
E       assert 404 == 200
E        +  where 404 = <Response [404]>.status_code

tests/test_author.py:16: AssertionError
============================================================================================================== 2 failed in 0.35s ==============================================================================================================

I tried to start the tests directly from the container shell but nothing the same. This problem occurs only with tests that are done following the documentation (using starlette / fastapi) and with requests

You can find the complete project here Library Microsrevices example

Environment

• OS:[Linux Fedora 32]
• FastAPI Version [0.55.1]:
• Python: [Python 3.8.3]

docker-compose file

version: '3.7'

services:
  book_service:
    build: ./book-service
    command: uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
    volumes:
      - ./book-service/:/app/
    ports:
      - 8001:8000
    environment:
      - DATABASE_URI=postgresql://book_db_username:book_db_password@book_db/book_db_dev
      - AUTHOR_SERVICE_HOST_URL=http://author_service:8000/api/v1/authors/
    depends_on:
      - book_db

  book_db:
    image: postgres:12.1-alpine
    volumes:
      - postgres_data_book:/var/lib/postgresql/data/
    environment:
      - POSTGRES_USER=book_db_username
      - POSTGRES_PASSWORD=book_db_password
      - POSTGRES_DB=book_db_dev
  
  author_service:
    build: ./author-service
    command: uvicorn app.main:app --reload --host 0.0.0.0 --port 8000
    volumes:
      - ./author-service/:/app/
    ports:
      - 8002:8000
    environment:
      - DATABASE_URI=postgresql://author_db_username:author_db_password@author_db/author_db_dev
    depends_on:
      - author_db

  author_db:
    image: postgres:12.1-alpine
    volumes:
      - postgres_data_author:/var/lib/postgres/data
    environment:
      - POSTGRES_USER=author_db_username
      - POSTGRES_PASSWORD=author_db_password
      - POSTGRES_DB=author_db_dev

  nginx:
    image: nginx:latest
    ports:
      - "8080:8080"
    volumes:
      - ./nginx_config.conf:/etc/nginx/conf.d/default.conf
    depends_on:
      - author_service
      - book_service

volumes:
  postgres_data_book:
  postgres_data_author: