add usage of environment variables

docker-compose.yml

@@ -32,14 +32,14 @@ services:
     build:
       context: ./backend
       dockerfile: Dockerfile
-    container_name: backend
+    container_name: "${BACKEND_HOST}"
     restart: unless-stopped
-    # ports:
-    #   - "${BACKEND_PORT}:8080"
     depends_on:
       - db
     networks:
       - app-network
+    env_file: 
+      - ./.env
 
   db:
     image: postgres:16
@@ -49,7 +49,5 @@ services:
       POSTGRES_USER: "${POSTGRES_USER}"
       POSTGRES_PASSWORD: "${POSTGRES_PASSWORD}"
       POSTGRES_DB: "${POSTGRES_DB}"
-    # ports:
-    #   - "${DB_PORT}:5432"
     networks:
       - app-network