volume to file system

docker-compose.yml

 version: '3'
 
 volumes:
-  postgres-data:
   redis-data:
 
 services:
     ports:
       - "127.0.0:5432:5432"
     volumes:
-      - postgres-data:/var/lib/postgresql/data
+      - ./db:/var/lib/postgresql/data
     environment:
       - POSTGRES_USER=${POSTGRES_USER:-postgres}
       - POSTGRES_PASSWORD=${POSTGRES_PASSWORD:-password}