How to get bridge support with /etc/network/interfaces? - linux

Question

There are some linux distros, where it is possible to configure a bridge in /etc/network/interfaces. As explained for example here, it is enough to use this to form a bridge:
iface eth0 inet manual
iface eth1 inet manual
iface br0 inet dhcp
bridge_ports eth0 eth1
I am building a custom linux image using yocto. In my image this is not working. Yocto version is morty, which is already 3 years old.
So, what I need to do to get this functionality? Is it enough to get a newer version of the ifupdown package (I assume that this package provides this functionality)?
I installed the bridge-utils package, and I could add a bridge using brctl, as explained here:
brctl addbr br0
brctl addif br0 eth0 eth1
but I do not want to do it manually. I would like to do it by modifying /etc/network/interfaces, because then the changes are saved between reboots.

Answer 1

Do you use systemd?
If so, try a bbappend of systemd-machine-units, e.g.:
FILESEXTRAPATHS_prepend := "${THISDIR}/systemd-machine-units:"
SRC_URI += " \
file://10-eth0.network \
file://10-eth1.network \
"
do_install_append() {
for file in $(find ${WORKDIR} -maxdepth 1 -type f -name *.network); do
install -m 0644 "$file" ${D}${systemd_unitdir}/network/
done
}