securitygroup: Ubuntu 20.04 fix systemvm cannot start up (#4303)
securitygroup: Ubuntu 20.04 fix systemvm cannot start up (#4303)

* security_group.py: fix SyntaxWarning: "is" with a literal.

2020-04-27 09:43:54,172 DEBUG [kvm.resource.LibvirtComputingResource] (Agent-Handler-2:null) (logid:c33ba330) /usr/share/cloudstack-common/scripts/vm/network/security_group.py:513: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if rules is None or rules is "":
/usr/share/cloudstack-common/scripts/vm/network/security_group.py:522: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if rules is None or rules is "":
/usr/share/cloudstack-common/scripts/vm/network/security_group.py:823: SyntaxWarning: "is" with a literal. Did you mean "=="?
  if brName is None or brName is "":

* Ubuntu 20.04: Fix systemvm cannot start up

in Ubuntu 16.04:

root@node13:~# bridge -o link show
2: eth0 state UP : <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloudbr0 state forwarding priority 32 cost 100
5: vnet0 state UNKNOWN : <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloud0 state forwarding priority 32 cost 100
6: vnet1 state UNKNOWN : <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloudbr0 state forwarding priority 32 cost 100
7: vnet2 state UNKNOWN : <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloudbr0 state forwarding priority 32 cost 100

root@node13:~# bridge -o link show | awk '/master cloudbr0 / && !/^[0-9]+: vnet/ {print $2}' | head -1
eth0

root@node13:~# bridge -o link show | awk '/master cloudbr0 / && !/^[0-9]+: vnet/ {print $2}' | head -1 |cut -d ":" -f1
eth0

in Ubuntu 20.04:

root@node62:~# bridge -o link show
2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloudbr0 state forwarding priority 32 cost 100
10: vnet3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloud0 state forwarding priority 32 cost 100
11: vnet4: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloudbr0 state forwarding priority 32 cost 100
12: vnet5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master cloudbr0 state forwarding priority 32 cost 100

root@node62:~# bridge -o link show | awk '/master cloudbr0 / && !/^[0-9]+: vnet/ {print $2}' | head -1
ens3:

root@node62:~# bridge -o link show | awk '/master cloudbr0 / && !/^[0-9]+: vnet/ {print $2}' | head -1 |cut -d ':' -f1
ens3

* security_group.py: use 'if not' instead
GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack,GabrielBrascher/cloudstack