Feature request: Replace Redis

Context

Docker Mailserver uses Redis. Redis screwed around with their license. Redis was originally licensed exclusively under the BSD-3 license, which is quite compatible with Docker Mailserver's MIT license. However, I believe that their new license is less compatible, and does not align with the values of the community that contributes to DMS.

Description

For the short term I would not change anything, since Redis still works and the way DMS includes Redis relies on standard Debian packages. The currently used Debian version does not offer an alternative yet, I believe. Ideally we will also not use community packages. While I am reluctant to continue to use Redis due to the questionable license (for now a "soft" concern), I am even more reluctant for the risk that stuff breaks (a "hard" concern). 😉

Valkey is a drop-in replacement for Redis developed and maintained by the Linux Foundation. It uses the BSD-3 license as Redis once used to. I expect that Valkey will be available in the future in Debian's repositories. Once it does, I expect that the pull request to replace Redis with Valkey will be relatively small.

If there would be a roadmap, I would suggest to add this to it. Otherwise, is it an idea to keep this issue open?

Alternatives

• Keep using Redis. I would not recommend this. Many open source projects are switching to alternatives, which shows that such one-sided license changes are frowned upon.
• There are some other drop-in alternatives to Redis being developed as well. For now I expect Valkey to be the best drop-in replacement in the future since it is backed by the Linux Foundation. It's fine if another replacement is a better fit if my expectation is wrong, of course.

Applicable Users

The entire community, including users and contributors.

Are you going to implement it?

Yes, because I know the probability of someone else doing it is low and I can learn from it.

What are you going to contribute?

If no one else is interested in implementing this, I'll be happy to make an attempt. To keep changes and maintenance to a minimum, I will wait until Debian includes Valkey or another drop-in alternative.