Cannot find required service quagga in /etc/init.d/

[root@kunpeng82 mininet]# ls /lib/systemd/system/zebra.service 
/lib/systemd/system/zebra.service
[root@kunpeng82 mininet]# vi  /lib/systemd/system/zebra.service 
[Unit]
Description=GNU Zebra routing manager
Wants=network.target
Before=network.target
ConditionPathExists=/etc/quagga/zebra.conf

[Service]
Type=forking
PIDFile=/run/quagga/zebra.pid
EnvironmentFile=-/etc/sysconfig/quagga
ExecStartPre=/sbin/ip route flush proto zebra
ExecStart=/usr/sbin/zebra -d $ZEBRA_OPTS -f /etc/quagga/zebra.conf
Restart=on-abort

[Install]
WantedBy=multi-user.target
[root@kunpeng82 mininet]# ls /lib/systemd/system/zebra.service 
/lib/systemd/system/zebra.service
[root@kunpeng82 mininet]# 

[root@kunpeng82 mininet]#  python sdx_mininext.py  
** Creating Quagga network topology
Cannot find required service quagga in /etc/init.d/.
Please make sure that Quagga (nongnu.org/quagga/) is installed [root@kunpeng82 mininet]# grep ‘Cannot find required serv quagga‘ -rn *
[root@kunpeng82 mininet]# ps -elf | grep zebra
1 S quagga   36047     1  0  80   0 -   418 do_sel 03:48 ?        00:00:00 /usr/sbin/zebra -d -A 127.0.0.1 -f /etc/quagga/zebra.conf
0 S root     37521 30515  0  80   0 -  1729 pipe_w 03:57 pts/0    00:00:00 grep --color=auto zebra
[root@kunpeng82 mininet]# vtysh

Hello, this is Quagga (version 0.99.22.4).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

kunpeng82.bogon# show running-config
Building configuration...

Current configuration:
!
hostname kunpeng82.bogon

[root@kunpeng82 mininet]# ln -s /usr/sbin/zebra  /etc/init.d/quagga
[root@kunpeng82 mininet]#  python sdx_mininext.py  
** Creating Quagga network topology
** Using Mininet Extended (MiniNExT) Handler
*** Creating network
*** Adding controller
Unable to contact the remote controller at 127.0.0.1:6653
Unable to contact the remote controller at 127.0.0.1:6633
Setting remote controller to 127.0.0.1:6653
*** Adding hosts: