how to add recipe for yocto systemd service - yocto

Question

I want to add custom yocto systemd service.
I referred to Enable systemd services using yocto
but my bb code is not working. It's not installed in filesystem.
(eth0.service code is okay)
How to fix it?
eth0_0.1.bb
SUMMARY = "Install and start a systemd service"
SECTION = "eth0"
LICENSE = "MIT"
LIC_FILES_CHKSUM = "file://${COMMON_LICENSE_DIR}/MIT;md5=0835ade698e0bcf8506ecda2f7b4f302"
SRC_URI += "file://eth0.service"
S = "${WORKDIR}"
inherit systemd
SYSTEMD_SERVICE_${PN} = "eth0.service"
do_install() {
install -d ${D}${systemd_system_unitdir}
install -m 0644 ${WORKDIR}/eth0.service ${D}${systemd_system_unitdir}/
}
FILES_${PN} += "/lib/systemd/system"
REQUIRED_DISTRO_FEATURES= "systemd"
eth0.service
[Unit]
Description=Network interfaces
Wants=network.target
Before=network.target
BindsTo=sys-subsystem-net-devices-eth0.device
After=sys.subsystem-net-devices-eth0.device
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/bin/sh -c "ifup eth0"
ExecStop=/bin/sh -c "ifdown eth0"
[Install]
WantedBy=multi-user.target

Answer 1

if you have inherit systemd and SYSTEMD_SERVICE_${PN} = "eth0.service" which you seem to have should have done it. So I think what you need to add is SYSTEMD_AUTO_ENABLE = "enable" a
nd make sure that .service file has [Install] section which you seem to have as well. Secondly also make sure package is added to image via IMAGE_INSTALL_append = " eth0" in local.conf

Answer 2

For network you can also create a systemd_%.bbappend with
FILESEXTRAPATHS_prepend := "${THISDIR}/files:"
SRC_URI += "file://eth0.network"
FILES_${PN} += "${systemd_unitdir}/network/*"
do_install_append() {
install -d ${D}${systemd_unitdir}/network/
install -m 0644 ${WORKDIR}/*.network ${D}${systemd_unitdir}/network/
}
with files/eth0.network:
[Match]
Name=eth0
[Network]
DHCP=ipv4