Add the netlink_event_tracker to handle netlink event

[hwchiu]

• The Server support the netlink event tracker now.
• It will remove the veth from OVS after the container has been removed.
• Since some testing will change the ovs command file mode, we should force the parallel=1 to avoid testing fail.

[codecov]

Codecov Report

Merging #27 into master will decrease coverage by 0.5%.
The diff coverage is 79.54%.

@@            Coverage Diff             @@
##           master      #27      +/-   ##
==========================================
- Coverage   85.03%   84.53%   -0.51%     
==========================================
  Files           5        7       +2     
  Lines         127      181      +54     
==========================================
+ Hits          108      153      +45     
- Misses         12       19       +7     
- Partials        7        9       +2

Impacted Files	Coverage Δ
nl/link.go	65.9% <ø> (ø)
nl/netlink_event.go	75% <75%> (ø)
nl/netlink_handler.go	87.5% <87.5%> (ø)
openvswitch/ovs.go	100% <0%> (ø)	⬆️

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[John-Lin]

package name seems wrong

[John-Lin]

package name seems wrong

[John-Lin]

Should consider the netlink event tracker only activate in unix domain socket server since we'll run two kinds of grpc servers

[hwchiu]

I will add a option to start the event track and we can decide which server should active that function from the arguments.

[John-Lin]

I would like to propose the flag names and usage descriptions

flag.BoolVar(&nlEventTracker, "track-netlink", false, "Run as a netlink event tracker for garbage collection")

// OR

flag.BoolVar(&nlEventTracker, "netlink-gc", false, "Run as a netlink event tracker for garbage collection")

the command can be used like

./network-controller -unix=/tmp/grpc.sock -track-netlink=true

OR

./network-controller -unix=/tmp/grpc.sock -netlink-gc=true

[zyfdegh]

Bool flags do not require users to specify true or false statement, to say, using --track-netlink is Okay which means true, not -track-netlink=true. ;)

[hwchiu]

@zyfdegh Thanks.
According to the manual. we need to avoid the usage -xxx true which is not support in bool form

-flag
-flag=x
-flag x  // non-boolean flags only