We were detecting the IP family that kube-proxy should use
based on the bind address, however, this is not valid when
using an unspecified address, because on those cases
kube-proxy adopts the IP family of the address reported
in the Node API object.
The IP family will be determined by the nodeIP used by the proxier
The order of precedence is:
1. config.bindAddress if bindAddress is not 0.0.0.0 or ::
2. the primary IP from the Node object, if set
3. if no IP is found it defaults to 127.0.0.1 and IPv4
Signed-off-by: Antonio Ojea <antonio.ojea.garcia@gmail.com>
Kube-proxy's iptables mode used to care whether utiliptables's
EnsureRule was able to use "iptables -C" or if it had to implement it
hackily using "iptables-save". But that became irrelevant when
kube-proxy was reimplemented using "iptables-restore", and no one ever
noticed. So remove that check.
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.
These are based on recommendation from
[staticcheck](http://staticcheck.io/).
- Removes dead type/function along with the import that the function
introduced.
- Removes unused struct fields.
- Removes select nested in a tight for loop, the select does not have a
default, so it will be blocking.
