"iptables-save" takes several seconds to run on machines with lots of
iptables rules, and we only use its result to figure out which chains
are no longer referenced by any rules. While it makes things less
confusing if we delete unused chains immediately, it's not actually
_necessary_ since they never get called during packet processing. So
in large clusters, make it so we only clean up chains periodically
rather than on every sync.
We don't need to parse out the counter values from the iptables-save
output (since they are always 0 for the chains we care about). Just
parse the chain names themselves.
Also, all of the callers of GetChainLines() pass it input that
contains only a single table, so just assume that, rather than
carefully parsing only a single table's worth of the input.
The iptables and ipvs proxies have code to try to preserve certain
iptables counters when modifying chains via iptables-restore, but the
counters in question only actually exist for the built-in chains (eg
INPUT, FORWARD, PREROUTING, etc), which we never modify via
iptables-restore (and in fact, *can't* safely modify via
iptables-restore), so we are really just doing a lot of unnecessary
work to copy the constant string "[0:0]" over from iptables-save
output to iptables-restore input. So stop doing that.
Also fix a confused error message when iptables-save fails.
kube-proxy generates iptables rules to forward traffic from Services to Endpoints
kube-proxy uses iptables-restore to configure the rules atomically, however,
this has the downside that large number of rules take a long time to be processed,
causing disruption.
There are different parameters than influence the number of rules generated:
- ServiceType
- Number of Services
- Number of Endpoints per Service
This test will fail when the number of rules change, so the person
that is modifying the code can have feedback about the performance impact
on their changes. It also runs multiple number of rules test cases to check
if the number of rules grows linearly.
Sort the ":CHAINNAME" lines in the same order as the "-A CHAINNAME"
lines (meaning, KUBE-NODEPORTS and KUBE-SERVICES come first).
(This will simplify IPTablesDump because it won't need to keep track
of the declaration order and the rule order separately.)
The various loops in the LoadBalancer rule section were mis-nested
such that if a service had multiple LoadBalancer IPs, we would write
out the firewall rules multiple times (and the allowFromNode rule for
the second and later IPs would end up being written after the "else
DROP" rule from the first IP).
The LoadBalancer rules change if the node IP is in one of the
LoadBalancerSourceRange subnets, so make sure to set nodeIP on the
fake proxier so we can test this, and add a second source range to
TestLoadBalancer containing the node IP. (This changes the result of
one flow test that previously expected that node-to-LB would be
dropped.)
Add TestInternalExternalMasquerade, which tests whether various
packets are considered internal or external for purposes of traffic
policy, and whether they get masqueraded, with and without
--masquerade-all, with and without a working LocalTrafficDetector.
(This extends and replaces the old TestMasqueradeAll.)
Add a new framework for testing out how particular packets would be
handled by a given set of iptables rules. (eg, "assert that a packet
from 10.180.0.2 to 172.30.0.41:80 gets NATted to 10.180.0.1:80 without
being masqueraded"). Add tests using this to all of the existing unit
tests.
This makes it easier to tell whether a given code change has any
effect on behavior, without having to carefully examine the diffs to
the generated iptables rules.
We originally had one HealthCheckNodePort test that used
assertIPTablesRulesEqual() and one that didn't, but later I went
through and made all the tests use assertIPTablesRulesEqual() and
didn't notice that this resulted in there now being two
nearly-identical HealthCheckNodePort tests.
This makes the "destination" policy model clearer. All external
destination captures now jump to the "XLB chain, which is the main place
that masquerade is done (removing it from most other places).
This is simpler to trace - XLB *always* exists (as long as you have an
external exposure) and never gets bypassed.
No functional changes, much whitespace.
Make assertIPTablesRulesEqual() *not* sort the `expected` value - make
the test cases all be pre-sorted. This will make followup commits
cleaner.
Make the test output cleaner when this fails.
Use dedent everywhere for easier reading.
Fix internal and external traffic policy to be handled separately (so
that, in particular, services with Local internal traffic policy and
Cluster external traffic policy do not behave as though they had Local
external traffic policy as well.
Additionally, traffic to an `internalTrafficPolicy: Local` service on
a node with no endpoints is now dropped rather than being rejected
(which, as in the external case, may prevent traffic from being lost
when endpoints are in flux).
Now the XLB chain _only_ implements the "short-circuit local
connections to the SVC chain" rule, and the actual endpoint selection
happens in the SVL chain.
Though not quite implemented yet, this will eventually also mean that
"SVC" = "Service, Cluster traffic policy" as opposed to "SVL" =
"Service, Local traffic policy"
Rather than lazily computing and then caching the endpoint chain name
because we don't have the right information at construct time, just
pass the right information at construct time and compute the chain
name then.
