To run Redis as the Unix socket, I have changed the group in the file at /etc/systemd/system/redis.service
But when I update the system, the Redis get upgrade also if there is a new version, and the change in the file /etc/systemd/system/redis.service is lost.
Do you know how to keep the file redis.service when I upgrade Redis?
This is not related to Hestia but… you should create an override.conf file for your service:
Let’s say you want to replace Group=redis to Group=random
Edit service with this command (it will create a file /etc/systemd/system/redis-server.service.d/override.conf:
systemctl edit redis.service
And here write the changes you need including the section. It is a good practice to blank first the variable and then apply the change just in case there are several variables with the same name.
### Editing /etc/systemd/system/redis-server.service.d/override.conf
### Anything between here and the comment below will become the new contents of the file
[Service]
Group=
Group=random
### Lines below this comment will be discarded
[...]
Save the file, reload systemd daemon files and restart redis.