Many people have problems for setting connectivity between containers, home private network and Internet on Synology NAS. There’re few different points than normal linux systems such as Synology NAS has no built-in docker-compose program and it has the tricky firewall. Below will use them as example: docker images of postgresql A and express.js B from official on dockerhub DSM 6.2.4-25556 Update 6 Reverse proxy server on DSM Firewall on DSM