[Unit]
Description=Tango Frontend Engine - Running Environment Setup
Requires=tfe-env.service
Before=tfe-env.service sapp.service
After=network-online.target
Wants=network-online.target

[Service]
EnvironmentFile=/etc/sysconfig/tfe-env-config
Type=oneshot
RemainAfterExit=yes

# all works are done in execstartpre, this is only a fake target
ExecStart=/bin/true
ExecStop=/bin/true

# start
ExecStartPost=/usr/sbin/ip tuntap add dev ${TFE_DEVICE_DATA_INCOMING} mode tap one_queue

# stop
ExecStopPost=/usr/bin/systemctl stop tfe-env
ExecStopPost=/usr/sbin/ip tuntap del dev ${TFE_DEVICE_DATA_INCOMING} mode tap

[Install]
WantedBy=multi-user.target
RequiredBy=sapp.service