- Set an explicit umask that allows u+rwx and g+r.
- Adds `ProtectControlGroups` and `ProtectKernelLogs`, there should be
no need to access either.
- Adds `ProtectClock` to prevent write-access to the system clock.
- `ProtectProc` hides processes from other users within the /proc
filesystem and `ProcSubSet` hides all files/directories unrelated to
the process management of the units process.
- Sets `RemoveIPC`, as there is no SysV or POSIX IPC within nginx that I
know of.
- Restricts the creation of arbitrary namespaces
- Adds a reasonable `SystemCallFilter` preventing calls to @privileged,
@obsolete and others.
And finally applies some sorting based on the order these options appear
in systemd.exec(5).