Docker compose with minimal nginx reverse-proxy with localhost subdomain

docker-compose.yml

version: '3.9'

services:
  nginx:
    image: nginx:1.20.2-alpine
    ports:
      - 80:80
    volumes:
      - ./nginx.conf:/etc/nginx/nginx.conf:ro
    depends_on:
        - api
        - web

  api:
    image: dannyben/whoami
    container_name: api
    expose:
      - 3000
    environment:
      MESSAGE: I am api.localhost

  web:
    image: dannyben/whoami
    container_name: web
    expose:
      - 3000
    environment:
      MESSAGE: I am the web.localhost

nginx.conf

events {

}

http {
    server {
        listen 80 default_server;
        listen [::]:80 default_server;

        server_name _;

        location / {
            proxy_pass http://web:3000;
        }
    }

    server {
        listen 80;
        listen [::]:80;

        server_name api.localhost;

        location / {
            proxy_pass http://api:3000;
        }
    }
}

$ docker-compose up -d