[virsh plugin] take network scripts backup only if they exists

[venkataanil]

Below ansible task is failing when running infrared virsh command to create VMs with multiple interfaces using linux bridges.

TASK [backup interface network configuration] *******************************************************************************************************************************
fatal: [hypervisor-0]: FAILED! => {"changed": false, "msg": "Source /etc/sysconfig/network-scripts/ifcfg-enp94s0f3 not found"}
fatal: [hypervisor-1]: FAILED! => {"changed": false, "msg": "Source /etc/sysconfig/network-scripts/ifcfg-enp94s0f3 not found"}

--topology-network configuration file which I am using is https://gist.github.com/venkataanil/f5a2a30ececc4a93d03aebe20fa52439

[root@f05-h10-000-1029p ~]# ls /etc/sysconfig/network-scripts/
ifcfg-eno1 ifdown-bnep ifdown-ipv6 ifdown-routes ifdown-tunnel ifup-eth ifup-isdn ifup-ppp ifup-TeamPort network-functions
ifcfg-eno2 ifdown-eth ifdown-isdn ifdown-sit ifup ifup-ib ifup-plip ifup-routes ifup-tunnel network-functions-ipv6
ifcfg-lo ifdown-ib ifdown-post ifdown-Team ifup-aliases ifup-ippp ifup-plusb ifup-sit ifup-wireless
ifdown ifdown-ippp ifdown-ppp ifdown-TeamPort ifup-bnep ifup-ipv6 ifup-post ifup-Team init.ipv6-global

[root@f05-h10-000-1029p ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether 0c:c4:7a:fa:18:c2 brd ff:ff:ff:ff:ff:ff
inet 10.1.41.51/23 brd 10.1.41.255 scope global noprefixroute dynamic eno1
valid_lft 256932sec preferred_lft 256932sec
3: eno2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
link/ether 0c:c4:7a:fa:18:c3 brd ff:ff:ff:ff:ff:ff
4: enp94s0f0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether ac:1f:6b:2d:1b:24 brd ff:ff:ff:ff:ff:ff
5: enp94s0f1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether ac:1f:6b:2d:1b:25 brd ff:ff:ff:ff:ff:ff
6: enp94s0f2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether ac:1f:6b:2d:1b:26 brd ff:ff:ff:ff:ff:ff
7: enp94s0f3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
link/ether ac:1f:6b:2d:1b:27 brd ff:ff:ff:ff:ff:ff
12: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
link/ether 52:54:00:27:ff:69 brd ff:ff:ff:ff:ff:ff
inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
valid_lft forever preferred_lft forever
13: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
link/ether 52:54:00:27:ff:69 brd ff:ff:ff:ff:ff:ff