With the flag, ipvs uses both source IP and source port (instead of
only source IP) to distribute new connections evently to endpoints
that avoids sending all connections from the same client (i.e. same
source IP) to one single endpoint.
User can explicitly set sessionAffinity in service spec to keep all
connections from a source IP to end up on the same endpoint if needed.
Change-Id: I42f950c0840ac06a4ee68a7bbdeab0fc5505c71f
ipvs `getProxyMode` test fails on mac as `utilipvs.GetRequiredIPVSMods`
try to reach `/proc/sys/kernel/osrelease` to find version of the running
linux kernel. Linux kernel version is used to determine the list of required
kernel modules for ipvs.
Logic to determine kernel version is moved to GetKernelVersion
method in LinuxKernelHandler which implements ipvs.KernelHandler.
Mock KernelHandler is used in the test cases.
Read and parse file is converted to go function instead of execing cut.
