Basic network bridge configuration for a laptop running Debian

In many different situations, mainly related to virtualization or containers, a basic linux bridge configuration is needed, typically defining br0 connected to the first Ethernet interface, eth0 (no, I don’t like predictable network interface names ;) ). In such a case, a basic configuration of «/etc/network/interfaces» must be similar to:

auto lo 
iface lo inet loopback

iface eth0 inet manual

auto br0
iface br0 inet dhcp
  bridge_ports eth0