How to persist data in a dockerized postgres database using volumes

My docker compose file has three containers, web, nginx, and postgres. Postgres looks like this: postgres: container_name: postgres restart: always image: postgres:latest volumes: - ./database:/var/lib/postgresql ports: - 5432:5432 My goal is to mount a volume which corresponds to a local folder called `./database` inside the postgres container as `/var/lib/postgres`. When I start these containers and insert data into postgres, I verify that `/var/lib/postgres/data/base/` is full of the data I'm adding (in the postgres container), but in my local system, `./database` only gets a `data` folder in it, i.e. `./database/data` is created, but it's empty. Why? Notes: - [This suggests my above file should work.](https://github.com/docker/compose/issues/2971) - [This person is using docker services which is interesting](https://stackoverflow.com/questions/39175194/docker-compose-persistent-data-mysql) ### UPDATE 1 Per Nick's suggestion, I did a `docker inspect` and found: "Mounts": [ { "Source": "/Users/alex/Documents/MyApp/database", "Destination": "/var/lib/postgresql", "Mode": "rw", "RW": true, "Propagation": "rprivate" }, { "Name": "e5bf22471215db058127109053e72e0a423d97b05a2afb4824b411322efd2c35", "Source": "/var/lib/docker/volumes/e5bf22471215db058127109053e72e0a423d97b05a2afb4824b411322efd2c35/_data", "Destination": "/var/lib/postgresql/data", "Driver": "local", "Mode": "", "RW": true, "Propagation": ""...