I want to recreate a service, including its volumes. The closest I got was the following commands:

docker-compose stop foo
docker-compose rm -f foo
docker-compose up --renew-anon-volumes -d foo
docker-compose start foo

The issue here is --renew-anon-volumes recreates all services that have anonymous volumes, not just foo's volumes. If I don't use --renew-anon-volumes, then I think I need a named volume to do docker volume rm myvolume. However, with named volumes, Docker Compose always prepends a project name. Since my script doesn't know the project name, I can't programmatically delete the volume. I can't enforce that the user uses a particular project name. I know I can set the project name using an environment variable, but there's no guarantee that the user won't run Docker Compose with a different project name.

I think there are 2 potential solutions:

1. Make --renew-anon-volumes only recreate the volumes for the service I specified

2. Use a named volume and somehow figure out the correct prefix

Are either of these doable, or is there another solution?

CodePudding user response：

Many roads leading to Rome, depending on your prerequisites:

1. Do docker volume ls and regex the result for your named volume (just working if volume name is unique)
2. Use external volumes and volume create them with known names by bootstrap script before running docker-compose up (not working if volumes must be instantiated)
3. Set project name to a known value. Normally it takes the folder name, but can explicitly given in docker-compose command (-p NAME) or by environment variable (COMPOSE_PROJECT_NAME=NAME).
4. Setup a dummy compose-file just containing this single service with its volumes for your script. Doing a docker-compose -f 'your-down-file.yml' down -v which removes all named and anonymous volumes belonging to this service and docker-compose -f .. up on this file.

Edit (@DavidMaze):

You're right, docker compose recognizes that fact. But it does NOT remove it, just warning. If you want to remove all "orphans" you need the flag --remove-orphans. But for some reasons the down does not remove volumes then, even if flag -v is given. This could be reported because it is not behaving like described.

And errata: the flag -f must go before up/down and not after!

CodePudding user response：

docker-compose rm has a -v option to delete anonymous volumes attached to a container, and also a -s option to stop the container. For your particular use case it should be enough to:

docker-compose rm -s -f -v foo
docker-compose up -d foo

This will only help for anonymous volumes, that is, where the Compose file has volumes: with only a container path and there is no corresponding top-level volumes: entry. I don't immediately see a Compose option to list, remove, or otherwise manage named volumes that Compose created.