Seems to work:
services:
lldpd:
image: ibhde/lldpd
cap_add:
- NET_ADMIN
- NET_RAW
network_mode: host
hostname: truenas.mydomain.lan
command:
- -x
- -I
- eno*
environment:
- TZ=Europe/Berlin
volumes:
- /var/agentx:/var/agentx
networks: {}