coturn, systemd with reload & CAP_NET_BIND_SERVICE

coturn.service

[Unit]
Description=coTURN STUN/TURN Server
Documentation=man:coturn(1) man:turnadmin(1) man:turnserver(1)
After=network.target

[Service]
AmbientCapabilities=CAP_NET_BIND_SERVICE
User=turnserver
Group=turnserver
Type=forking
RuntimeDirectory=turnserver
PIDFile=/run/turnserver/turnserver.pid
ExecStart=/usr/bin/turnserver --daemon -c /etc/turnserver.conf --pidfile /run/turnserver/turnserver.pid
ExecReload=/bin/kill -SIGUSR2 $MAINPID
#FixMe: turnserver exit faster than it is finshing the setup and ready for handling the connection.
ExecStartPost=/bin/sleep 2
Restart=on-failure
InaccessibleDirectories=/home
PrivateTmp=yes

[Install]
WantedBy=multi-user.target

turnserver.conf

tls-listening-port=443
min-port=49152
max-port=65535
fingerprint
static-auth-secret=
external-ip=
external-ip=
realm=
stale-nonce
use-auth-secret
cert=/etc/turn/cert.pem
pkey=/etc/turn/key.pem
cipher-list=ALL
mobility
simple-log
syslog