Support Redis and Memcached as session handler

[J0WI]

Is your feature request related to a problem? Please describe.
It would be great to have the ability to set Memcached or Redis as session handler in NextCloud.
This could be a significant performance gain compared to the default file handler.

Describe the solution you'd like
I'd like to have an option similar to the existing ones for file locking. E.g.

'memcache.session' => '\\OC\\Memcache\\Redis'

Describe alternatives you've considered
Up to now you have to configure them manually in PHP:

session.save_handler = redis
session.save_path = "tcp://redis-server"

session.save_handler = memcached
session.save_path = "memcached-server"

[rullzer]

I do not think it is a good idea to start implementing our own session handling. These kind of things should be handled properly by php itself I think.

[GuyPaddock]

One challenge we're having in our deployment is that when running in a cluster, users get CSRF errors when their request is routed between Docker instances. I think the issue here is that the session is storing the CSRF token but that session doesn't move between instances.

How do Nextcloud clusters normally work around this issue if sessions can't be stored in Redis?

[kesselb]

The most reliable way is to change php session handler like suggested above as alternative solution.

[GuyPaddock]

Can the session handler be modified on-the-fly during NC startup?

[GuyPaddock]

Separately, I found a solution by having my Docker entrypoint.sh for Nextcloud write-out the Redis session connection string on the fly. I will post a link as soon as my changes have been pushed to the Nextcloud resource kit I'm working on.

[GuyPaddock]

Here's what I came up with in my entrypoint.sh, if it's useful to anyone else:
Inveniem/nextcloud-azure-aks@9b9c73c#diff-3fcf514429a2e9e913084c350892c067R66

The Redis config is already passed to the container via environment variables. This gets used to setup PHP's session handling on start-up.

Separately, those same environment variables are used to setup Nextcloud's in-memory cache here:
Inveniem/nextcloud-azure-aks@9b9c73c#diff-4027a37b5fb90805a18b0a60333859e0

[J0WI]

We have a pending PR to support Redis in Docker:
nextcloud/docker#600
I actually planned to also add a session handler option after nextcloud/docker#600 is merged. So I'd welcome an upstream PR of your changes.

[GuyPaddock]

@J0WI Happy to oblige after nextcloud/docker#600 gets merged.

[matt-horwood-mayden]

Afternoon, this would really help me!

I have a pi that runs my nextcloud instance and I'm looking at how I can move it to a docker setup with multi pis, but I cant seem to make it work without editing the php session handler.

Currnet setup

nginx(pi1) -> php-fpn/nginx(pi2) -|-> mysql(pi3)
                                  |-> nfs(pi4)

Docker (using traefik to LB more than 1 container)

nginx(pi1) -> docker1(pi2) -|-> mysql(pi3)
              docker1(pi2) -|-> nfs(pi4)

[J0WI]

@GuyPaddock nextcloud/docker#600 is merged 😉

[kesselb]

@J0WI okay for you to close this issue? I guess we found a good way how to handle this case.

[J0WI]

This is only solved for the Docker image so far.