Optimize performance? APP_NICENESS?

[SawkeeReemo]

Running docker-firefox in a container on my Synology NAS, I'm noticing that everything I click on has a decent amount of lag, and the loading of even light weight pages or using Bitwarden to fill passwords is very slow. I wanted to see if using the APP_NICENESS environmental variable might increase my performance.

Secondly, how do you run the required docker option --cap-add=SYS_NICE from a docker compose file? I tried both of the following, but my container failed to start:

command:
     - --cap-add=SYS_NICE

and

command:
     - cap-add=SYS_NICE

But neither seemed to be correct.

The error I'm receiving is:
Error response from daemon: failed to create shim task: OCI runtime create failed: runc create failed: unable to start container process: exec: "cap-add=SYS_NICE": executable file not found in $PATH: unknown

[jlesage]

Try to add the capability to your compose file like this:

cap_add:
  - SYS_NICE