I used to be able to simply setup redis operation with unix sockets only by simply changing the redis.conf file and restarting. But now I have to change the redis-server.service systemd unit file to a bare minimum to get it running.
I searched for documentation but did not find any and hope that there is also a way to run on a unix socket with a different user than root (wont start if user and group defined in the .service file) and with all the restrictions you have in place there as there are surely some security advantages to them.
My bare minimum .service file looks like this now to get it running:
[Unit]
Description=Advanced key-value store
After=network.target
Documentation=http://redis.io/documentation, man:redis-server(1)
[Service]
Type=forking
ExecStart=/usr/bin/redis-server /etc/redis/redis.conf
ExecStop=/bin/kill -s TERM $MAINPID
[Install]
WantedBy=multi-user.target
Alias=redis.service
The redis.conf values changed from standard are:
port 0
unixsocket /run/redis.sock
unixsocketperm 775