Database Migration. about permissions2 HOT 1 CLOSED

Hi @siredwin. It warms my soul that you've used permissions2 for 4+ years.

I would be happy to help out both in making the user management system more robust and/or with details about the database setup. I can't think of any potential security issues with discussing this here, since all the code is also open source and readily reviewable by anyone.

permissions2 uses Redis in the most straightforward way I could think of, which is a hash map of users called "users". The username + ":" + property key name is the hash map key:
https://github.com/xyproto/permissions2/blob/main/userstate.go#L162

To be able to quickly index all the keys, there is also a list of all the usernames:
https://github.com/xyproto/permissions2/blob/main/userstate.go#L165

Then, there is also a list of users that have registered, but are not yet confirmed (by, say, clicking an e-mail link):
https://github.com/xyproto/permissions2/blob/main/userstate.go#L168

In order to store a username together with other properties, like for instance prefersDarkMode=true, the username + ":" + the key for the property are used as the hash map key, and "true" for the value. For example, for the user bob:

• Redis hash map key: bob:prefersDarkMode
• Redis hash map value: true

The layer between Redis and permissions2 is the simpleredis package. That is where the : between the two keys comes from. Here is the implementation of the HashMap, which uses the HSET command in Redis:

https://github.com/xyproto/simpleredis/blob/main/simpleredis.go#L447

Given a username, like bob as the "elementid" parameter, this function can be used for listing all the property keys:

https://github.com/xyproto/simpleredis/blob/main/simpleredis.go#L508

Redis is more robust than people generally first have the impression of, though, and has settings for persisting data to disk. It's not only a database for storing data in memory. I would be very interested in hearing about which types of robustness gains you are envisioning.

from permissions2.