kvm: Security Group enhancements and refactor old code (#3113)

* security group: Replace deprecated optparse by argparse

Starting with Python 2.7 the library optparse has been replaced by
argpase.

This commit replaces the use of optparse by argparse

Signed-off-by: Wido den Hollander <wido@widodh.nl>

* security group: Remove LXC support from security_group.py

LXC does not work and has been partially removed from CloudStack already

Signed-off-by: Wido den Hollander <wido@widodh.nl>

* security group: Refactor libvirt code

Use a single function which properly throws an Exception when the
connection to libvirt fails.

Also simplify some logic, make it PEP-8 compatible and remove a unused
function from the code.

Signed-off-by: Wido den Hollander <wido@widodh.nl>

* security group: Raise Exception on execute() failure

If the executed command exists with a non-zero exit status we should
still return the output to the command, but also raise an Exception.

Signed-off-by: Wido den Hollander <wido@widodh.nl>

* security group: Use a function to determin the physical device of a bridge

We can not safely assume that the first device listed under a bridge is the
physical device.

With VXLAN isolation a vnet device can be attached to a bridge prior to the
vxlanXXXX device being attached.

We need to filter out those devices and then fetch the physical device attached
to the bridge.

In addition use the 'bridge' command instead of 'brctl'. 'bridge' is part of the
iproute2 utils just like 'ip' and should be considered as the new default.

This command is also available on EL6 and does not break any backwards compat.

Signed-off-by: Wido den Hollander <wido@widodh.nl>

* security group: --set is deprecated, use --match-set

These messages are seen in the KVM Agent log:

  --set option deprecated, please use --match-set

Functionality does not change

Signed-off-by: Wido den Hollander <wido@widodh.nl>

* security group: PEP-8 and indentation fixes

There were a lot of styling problems in the code:

- Missing whitespace or exess whitespace
- CaMelCaSe function names and variables
- 2-space indentation instead of 4 spaces

This commit addresses those issues.

Signed-off-by: Wido den Hollander <wido@widodh.nl>

Author: wido

plugins/hypervisors/kvm/src/main/java/com/cloud/hypervisor/kvm/resource/LibvirtComputingResource.java

@@ -3491,7 +3491,7 @@ protected long getMemoryFreeInKBs(Domain dm) throws LibvirtException {
     private boolean canBridgeFirewall(final String prvNic) {
         final Script cmd = new Script(_securityGroupPath, _timeout, s_logger);
         cmd.add("can_bridge_firewall");
-        cmd.add(prvNic);
+        cmd.add("--privnic", prvNic);
         final String result = cmd.execute();
         if (result != null) {
             return false;