Systemd containers

Docker is not the only containers engine in the market. One of the most interesting alternatives are the systemd containers, a solution tightly integrated with the operating system internals. Systemd containers are build around systemd-nspawn and systemd-machined (a tiny daemon that tracks locally running Virtual Machines and Containers in various ways).

In the network part of this equation we can find

• systemd-networkd, a daemon that, when a virtual Ethernet tunnel appears for a container, picks an IP range for the container, run a DHCP server for it, set up IPv4LL, set up network address translation, etc.
• systemd-resolved, a centralized daemon that maintains a single, global cache for names resolutions, performing lookups with LLMNR.