When launching icinga2 with systemd, it will source /etc/conf.d/icinga2 as environment file. However, this file misses ICINGA2_RUN_DIR="/run/icinga2", which is, for openrc defined in /etc/init.d/icinga2, leading to the creation of a "/icinga2" folder. I guess "ICINGA2_RUN_DIR" should be added to /etc/conf.d/incinga2.
https://wiki.gentoo.org/wiki/Project:Systemd/conf.d_files
Ok, I see thanks for this I did not know. But then a problem remains : icinga2 sources as environment file a conf.d file, which should not be the case right ? If so I'll edit the description of the bug, else I will close it. Thanks !
We don't install a custom unit file, I'd suggest making a bug upstream. I did add it to the conf.d file though