3948f16ff4
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.
138 lines
3.5 KiB
Go
138 lines
3.5 KiB
Go
/*
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Copyright 2015 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package testing
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import (
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"bytes"
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"fmt"
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"strings"
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"time"
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"k8s.io/kubernetes/pkg/util/iptables"
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)
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const (
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Destination = "-d "
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Source = "-s "
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DPort = "--dport "
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Protocol = "-p "
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Jump = "-j "
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Reject = "REJECT"
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ToDest = "--to-destination "
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Recent = "recent "
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MatchSet = "--match-set "
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SrcType = "--src-type "
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Masquerade = "MASQUERADE "
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)
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type Rule map[string]string
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// no-op implementation of iptables Interface
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type FakeIPTables struct {
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hasRandomFully bool
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Lines []byte
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}
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func NewFake() *FakeIPTables {
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return &FakeIPTables{}
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}
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func (f *FakeIPTables) SetHasRandomFully(can bool) *FakeIPTables {
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f.hasRandomFully = can
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return f
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}
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func (*FakeIPTables) EnsureChain(table iptables.Table, chain iptables.Chain) (bool, error) {
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return true, nil
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}
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func (*FakeIPTables) FlushChain(table iptables.Table, chain iptables.Chain) error {
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return nil
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}
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func (*FakeIPTables) DeleteChain(table iptables.Table, chain iptables.Chain) error {
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return nil
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}
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func (*FakeIPTables) EnsureRule(position iptables.RulePosition, table iptables.Table, chain iptables.Chain, args ...string) (bool, error) {
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return true, nil
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}
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func (*FakeIPTables) DeleteRule(table iptables.Table, chain iptables.Chain, args ...string) error {
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return nil
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}
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func (*FakeIPTables) IsIpv6() bool {
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return false
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}
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func (f *FakeIPTables) Save(table iptables.Table) ([]byte, error) {
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lines := make([]byte, len(f.Lines))
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copy(lines, f.Lines)
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return lines, nil
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}
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func (f *FakeIPTables) SaveInto(table iptables.Table, buffer *bytes.Buffer) error {
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buffer.Write(f.Lines)
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return nil
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}
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func (*FakeIPTables) Restore(table iptables.Table, data []byte, flush iptables.FlushFlag, counters iptables.RestoreCountersFlag) error {
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return nil
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}
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func (f *FakeIPTables) RestoreAll(data []byte, flush iptables.FlushFlag, counters iptables.RestoreCountersFlag) error {
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f.Lines = data
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return nil
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}
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func (f *FakeIPTables) Monitor(canary iptables.Chain, tables []iptables.Table, reloadFunc func(), interval time.Duration, stopCh <-chan struct{}) {
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}
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func getToken(line, separator string) string {
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tokens := strings.Split(line, separator)
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if len(tokens) == 2 {
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return strings.Split(tokens[1], " ")[0]
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}
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return ""
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}
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// GetChain returns a list of rules for the given chain.
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// The chain name must match exactly.
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// The matching is pretty dumb, don't rely on it for anything but testing.
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func (f *FakeIPTables) GetRules(chainName string) (rules []Rule) {
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for _, l := range strings.Split(string(f.Lines), "\n") {
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if strings.Contains(l, fmt.Sprintf("-A %v", chainName)) {
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newRule := Rule(map[string]string{})
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for _, arg := range []string{Destination, Source, DPort, Protocol, Jump, ToDest, Recent, MatchSet, SrcType, Masquerade} {
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tok := getToken(l, arg)
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if tok != "" {
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newRule[arg] = tok
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}
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}
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rules = append(rules, newRule)
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}
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}
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return
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}
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func (f *FakeIPTables) HasRandomFully() bool {
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return f.hasRandomFully
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}
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var _ = iptables.Interface(&FakeIPTables{})
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