wpa_supplicant.service (wlan0 + dbus)

[Unit]
Description=WPA supplicant (wlan0 + dbus)
BindsTo=sys-subsystem-net-devices-wlan0.device
After=sys-subsystem-net-devices-wlan0.device
Before=network.target
Wants=network.target
After=dbus.service

[Service]
Type=dbus
BusName=fi.w1.wpa_supplicant1
ExecStart=/usr/sbin/wpa_supplicant -O "DIR=/run/wpa_supplicant GROUP=netdev" -u -c /etc/wpa_supplicant/wpa_supplicant-wlan0.conf -Dnl80211 -i wlan0

[Install]
WantedBy=sys-subsystem-net-devices-wlan0.device