Add a configuration option to allow decide whether to prune volumes or not

[emibcn]

Hi @reubenmiller ,
We have some special volumes we don't ant to be removed when removing the compose where they where created. When stopping and removing a compose project, it shows the args, which includes --volumes:

2026/07/06 10:39:42 INFO Removing compose project. name=myproject dir=/var/lib/tedge-container-plugin/compose/myproject command=docker args="compose down --remove-orphans --volumes"

I believe a couple more options could be added:

• One to force all volumes to be pruned or not. It is currently being done (as if the option is now set to prune_volumes = True). I guess this solution would be the easiest one to implement (and we would set it to False).

• One for each volume or deployment. We would like to control whether that --volumes is being added, with as much granularity as possible. I don't know if it should be done in the config file (for example, having an array of volumes to maintain or projects whose volumes should not be purged), in the software definition itself (having a tick box to enable/disable volumes being purged), or in the docker-compose.yml file (for example, using a custom option, like x-volumes-keep).

Regards.

[reubenmiller]

Yeah it makes sense. For control over the container-group type, I think the x-volumes-keep (or something like that) would be the easiest, as then the user doesn't have to worry about the naming of volumes etc. Though I assume that if someone turns the removal of the volumes, then the user will have to manually delete it when deleting the app.

[emibcn]

Yeah it makes sense. For control over the container-group type, I think the x-volumes-keep (or something like that) would be the easiest, as then the user doesn't have to worry about the naming of volumes etc. Though I assume that if someone turns the removal of the volumes, then the user will have to manually delete it when deleting the app.

We would not need that (once our users have our product, they don't decide to remove it), but maybe for others would be nice to have an extra tool to manage all the volumes created by Thin Edge, to list or delete them.