This patch removes mount.Exec entirely and instead uses the common
utility from k8s.io/utils/exec.
The fake exec implementation found in k8s.io/utils/exec differs a bit
than mount.Exec, with the ability to pre-script expected calls to
Command.CombinedOutput(), so tests that previously relied on a callback
mechanism to produce specific output have been updated to use that
mechanism.
This patch moves fake.go to mount_fake.go, and follows to principle of
always returning a discrete type rather than an Interface. All callers
of "FakeMounter" are changed to instead use "NewFakeMounter()". The
FakeMounter "Log" struct member is changed to not be exported, and
instead only access through a new "GetLog()" method.
The tests were using a fake timer that only ticked when the test cases
told it to, so it would only be correctly testing the
BoundedFrequencyRunner functionality if the test cases made it tick
whenever the BFR timer was supposed to expire, and didn't make it tick
at any other time. But they didn't do that. Fix it to tick
automatically at the correct times, and update the test cases
accordingly (including adding a new helper method for asserting that
the runner did nothing in cases when it's expected to have done
nothing).
Also fix two unrelated minor bugs in fakeTimer.
Kubelet and kube-proxy both had loops to ensure that their iptables
rules didn't get deleted, by repeatedly recreating them. But on
systems with lots of iptables rules (ie, thousands of services), this
can be very slow (and thus might end up holding the iptables lock for
several seconds, blocking other operations, etc).
The specific threat that they need to worry about is
firewall-management commands that flush *all* dynamic iptables rules.
So add a new iptables.Monitor() function that handles this by creating
iptables-flush canaries and only triggering a full rule reload after
noticing that someone has deleted those chains.
The firewalld monitoring code was not well tested (and not easily
testable), would never be triggered on most platforms, and was only
being taken advantage of from one place (kube-proxy), which didn't
need it anyway since it already has its own resync loop.
Since the firewalld monitoring was the only consumer of pkg/util/dbus,
we can also now delete that.
Work around Linux kernel bug that sometimes causes multiple flows to
get mapped to the same IP:PORT and consequently some suffer packet
drops.
Also made the same update in kubelet.
Also added cross-pointers between the two bodies of code, in comments.
Some day we should eliminate the duplicate code. But today is not
that day.
This patch moves the HostUtil functionality from the util/mount package
to the volume/util/hostutil package.
All `*NewHostUtil*` calls are changed to return concrete types instead
of interfaces.
All callers are changed to use the `*NewHostUtil*` methods instead of
directly instantiating the concrete types.
