docker compose define container host names
$ cat docker-compose.yml
version: '3'
services:
nginx-1:
image: nginx
hostname: nginx-1.docker
network_mode: bridge
linux-1:
image: alpine
hostname: linux-1.docker
command: sh -c 'apk add --update bind-tools && tail -f /dev/null'
network_mode: bridge # that way he can solve others containers names even inside, solve nginx-2, for example