Docker-compose volume

General
1

Good afternoon! I don’t understand how, in the official mysql image, when you start the container, the data that / var / lib / mysql (volume) are all files are automatically forwarded to the host machine, how does it work?

2

Would you please share your docker-compose.yml? Your post doesn’t mention important facts and leaves them to the imagination.

3

version: ‘3.3’

services:
test_db:
image: “mysql/mysql-server:5.7”
container_name: test_db
restart: always
ports:
- 13306:3306
volumes:
- ./db:/var/lib/mysql
environment:
- TZ=${TZ}
- MYSQL_USER=123456
- MYSQL_PASSWORD=123
- MYSQL_DATABASE=123
- MYSQL_ROOT_PASSWORD=1234
- MYSQL_ROOT_HOST=%

4

This is where you declare a bind-mount, which results that everything inside the containre folder /var/lib/mysql will be stored in the subfolder db, relative to the the folder where you docker-compose.yml is located.

See: Compose file version 2 reference | Docker Docs for the documentation in the docker compose reference v2; If you are interessted in further details check Bind mounts | Docker Docs - even though it does not focus on the docker-compose.yml syntax, they are the very same concepts.

1 Like
5

Hello Impkos!
volumes:

  • ./db:/var/lib/mysql
    You was mount db Folder to var/lib/mysql
    Means Yours In your db Folder use access var/lib/mysql all data.