无法使用docker-compose挂载mongodb目录卷

Question

In my main project directory I have another local directory that I store my mongodb data in which is ./pokemondb . I know this directory is filled with my data because I have run mongoimport --db stats --colletion pokemon --file stats.json and can confirm the data is there in the mongo shell. I also have a docker-compose file that looks like this

pokemon-app:
  build: .
  ports:
    - "3000:3000"
  links:
    - mongo

mongo:
  image: mongo:3.2.4
  ports:
    - "27017:27017"
  volumes:
    - "./pokemondb:/data/db"

I run docker-compose up and no errors occur. But the problem is that the mongodb directory /data/db now doesn't contain the mounted volume I tried to pass. I can confirm that the data wasn't passed correctly by executing docker exec -ti [mongo container id] bash and checking the /data/db directory with the mongo shell, indeed nothing is there. What am I doing wrong and why is my mongodb data directory not mounting the volume correctly?

EDIT : I found an unexpected solution to my problem. One of my problems was that I had a fundamental misunderstanding of what docker volumes are. I previously thought that docker volumes were meant to copy data from your local machine into a docker container when it starts up. But in fact docker volumes are meant to save data on your local machine generated in the docker container. The solution the original problem I asked above was to create a dockerfile that copies the data into the image then import the data into the database when the container starts up. My final docker compose file looks like this.

app:
  build: .
  ports:
    - 3000:3000
  links:
    - mongodb

mongodb:
  image: mongo:3.2.4
  ports:
    - 27017:27017

stats:
  build: ./stats
  links:
    - mongodb

Answer 1

If you're using Docker Toolbox for OSX then only the home directory is available to the VM. If you're outside the your home directory, you need to either add another shared volume to the Virtualbox VM, or move the project under your home directory.