How to store and recover data from docker container?

Question

I'm using docker and docker-compose to deploy my flask app (btw I noticed the same issue with my django app as well). The issue is: when I start adding some static files or sqlite data to database.db it works fine while I'm running in docker, but when I restart my containers all data and static files are just gone. It seems like docker doesn't store data and just keep it inside the container. I added volumes to my service and it still doesn't work unfortunately.

My docker-compose.yml :

  1   version: '3.5'
    1 
    2 services:
    3   flask_app:
    4     container_name: flask_app
    5     build:
    6       context: .
    7       dockerfile: Dockerfile
    8     environment:
    9       - TBOT_SECRET_KEY='youwillneverguess'
   10       - TBOT_ADMIN_PASSWORD='qwerty'
   11       - TBOT_ADMIN_USERNAME='admin'
   12     ports:
   13       - "80:5000"
   14     restart: always
   15     volumes:
!  16       - db:/var/lib/tarkov_bot/data
   17 
   18 volumes:
!  19     db:

and the Dockerfile :

2   FROM python:3.7
  1 
  2 # create and set working directory
  3 RUN mkdir /app
  4 WORKDIR /app
  5 
  6 # Add current directory code to working directory
  7 ADD . /app/
  8 
  9 # set default environment variables
 10 ENV PYTHONUNBUFFERED 1
 11 ENV LANG C.UTF-8
 12 ENV DEBIAN_FRONTEND=noninteractive 
 13 
 14 # Install system dependencies
 15 RUN apt-get update && apt-get install -y --no-install-recommends \
 16         tzdata \
 17         python3-setuptools \
 18         python3-pip \
 19         python3-dev \
 20         python3-venv \
 21         git \
 22         && \
 23     apt-get clean && \
 24     rm -rf /var/lib/apt/lists/*
 25 
 26 
 27 # install environment dependencies
 28 RUN pip3 install --upgrade pip 
 29 
 30 # Install project dependencies
 31 RUN pip3 install -r requirements.txt
 32 
 33 EXPOSE 5000
 34 
 35 CMD gunicorn -b 0.0.0.0:5000 app:app

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Answer 1

I'm affraid docker volumes is the way to do that. If it's not working, it means that you need to mount more volumes where desired-persistent data are being stored.

Another possibility, not so elegant, is doing docker commit to save snapshot of your current docker, and save it as a new image.

I recommend first purpose: investigate what other files you need to save in your mounted volumes.