environment variables are not applied to container

docker-compose.yml

version: '3.7'

volumes:
  db_data:

services:
  app:
    build:
      context: ../
      dockerfile: docker/Dockerfile-app
    environment:
      RAILS_ENV: ${DOCKER_RAILS_ENV}
      MYSQL_ROOT_PASSWORD: ${DOCKER_MYSQL_ROOT_PASSWORD}
      MY_VAR: 1
    depends_on:
      - db
    container_name: app
    env_file: .env

  db:
    image: mysql:8.0.12
    environment:
      MYSQL_ROOT_PASSWORD: ${DOCKER_MYSQL_ROOT_PASSWORD}
    volumes:
      - db_data:/var/lib/mysql
    command: mysqld --default-authentication-plugin=mysql_native_password
    restart: always
    container_name: db

  nginx:
    build:
      context: ../
      dockerfile: docker/Dockerfile-nginx
    depends_on:
      - app
    ports:
      - ${DOCKER_NGINX_PORT}:80
    container_name: nginx

gistfile1.txt

ruby@vs03:~/www/docker.com/docker$ d run -it 73798d6f299e bash
root@ff13e1deff17:/var/www/citrus# printenv
RUBYGEMS_VERSION=2.7.7
BUNDLER_VERSION=1.16.5
HOSTNAME=ff13e1deff17
RUBY_VERSION=2.5.1
GEM_HOME=/usr/local/bundle
RAILS_ROOT=/var/www/citrus
PWD=/var/www/citrus
HOME=/root
BUNDLE_PATH=/usr/local/bundle
BUNDLE_APP_CONFIG=/usr/local/bundle
TERM=xterm
BUNDLE_SILENCE_ROOT_WARNING=1
RUBY_MAJOR=2.5
SHLVL=1
RUBY_DOWNLOAD_SHA256=886ac5eed41e3b5fc699be837b0087a6a5a3d10f464087560d2d21b3e71b754d
PATH=/usr/local/bundle/bin:/usr/local/bundle/gems/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
_=/usr/bin/printenv

tree

Чтобы было понятно как файлы докера лежат
ruby@vs03:~/www/docker.com/docker$ tree -a
.
├── docker-compose.yml
├── Dockerfile-app
├── Dockerfile-nginx
├── .env
└── nginx.conf