[FIXED] Does docker compose up -d --build clear db?

Issue

I am using a docker compose for my django app and postgres db. when I have a new migration docker compose up -d --build clears my data in db. I want to know what is wrong? --build may clear ?

my yaml file:

version: "3.9"

services:
  db:
    image: postgis/postgis:14-3.2
    volumes:
      - ./data/db:/var/lib/postgresql/data
    environment:
      - POSTGRES_DB=db
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=123456
    ports:
      - "5434:5432"

  web:
    restart: always
    build: .
    command:
      sh -c "python manage.py migrate  &&
             python manage.py runserver 0.0.0.0:8000"
    volumes:
      - .:/code
    ports:
      - "7000:8000"
    environment:
      - POSTGRES_NAME=db
      - POSTGRES_USER=user
      - POSTGRES_PASSWORD=123456
      - UPLOAD_LOCATION_MEDIA=/srv/app/cdn/media
      - UPLOAD_LOCATION_IMAGE=/srv/app/cdn/image
    depends_on:
      - db

Solution

In volumes path of db, map persist path of server to container path. Her the path is:

./data/db:/var/lib/postgresql/data

that should be change to:

/path-to-server-directory/db:/var/lib/postgresql/data

in rebuild db data in server directory will be unchanged.

Answered By - Ali Shekari