Feature Request: message & media retention

[Kimiblock]

Description:

Similar to https://github.com/element-hq/synapse, delete messages & medias from the database and media repo if contents weren't accessed in a configurable amount of time.

For reference: Synapse config manual 1 2

This can greatly benefit use cases with limited disk space, such as Dendrite on VPS.

[spaetz]

At the expense if self-promoting myself excessively: media retention kind if got implemented through a 3rd party tool (https://gitlab.com/sspaeth/cleanmedia).

If one needs a more finegrained policy, the dedicated media repository server is probably better suited which can be plugged into any server.

dendrite knows nothing about which media was posted in which room and when it was accessed last. So adding a rentention policy into the server is a lot of work.

Nothing of the above is about message retention though.

[Kimiblock]

Well… the intention of cleaning media not accessed in a certain amount of time is to preserve frequently used (and probably important) files, such as user avatars and sticker packs

[Kimiblock]

After a bit of digging, it turns out that MMR does support media retention and made a handy script https://github.com/Kimiblock/MMR-retention.

Not sure whether or not to close this issue though… as this still requires setting up MMR and Redis.