ACL

Posix Access Control Lists

Docs

• http://linuxhelp.blogspot.com/2005/11/get-exact-control-over-your-files-and.html
• Using rsync with acl

HOWTO

Set group writable

setfacl -R -d -m g::rwx .

Make logs readable for user

setfacl -R -m u:zabbix:rx /var/log/nginx/

FAQ

setfacl: Option -x: Invalid argument near character 16"

You only need like

setfacl -x group:somegroup