The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.
Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
We don't call klog.InitFlags yet, because that will cause a flag
redefinition error until we get everyone to stop using glog. That
will happen when we update to k8s 1.13.
Ubuntu 18.04 doesn't have a package for docker 17.03, but we can still
support it by using the tar.gz package.
This could be a nice fallback for other operating systems in future,
and it might prove to be more reliable than the OS packages.
But start with supporting ubuntu 18.04 with older docker versions!