Add a package for bandwidth control

pull/6/head
Brendan Burns 2015-07-29 09:25:27 -07:00
parent d04fce045e
commit dcd6b00d83
4 changed files with 620 additions and 0 deletions

18
pkg/util/bandwidth/doc.go Normal file
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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
// Package bandwidth provides utilities for bandwidth shaping
package bandwidth

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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package bandwidth
import "k8s.io/kubernetes/pkg/api/resource"
type BandwidthShaper interface {
// Limit the bandwidth for a particular CIDR on a particular interface
// * ingress and egress are in bits/second
// * cidr is expected to be a valid network CIDR (e.g. '1.2.3.4/32' or '10.20.0.1/16')
// 'egress' bandwidth limit applies to all packets on the interface whose source matches 'cidr'
// 'ingress' bandwidth limit applies to all packets on the interface whose destination matches 'cidr'
// Limits are aggregate limits for the CIDR, not per IP address. CIDRs must be unique, but can be overlapping, traffic
// that matches multiple CIDRs counts against all limits.
Limit(cidr string, egress, ingress resource.Quantity) error
// Remove a bandwidth limit for a particular CIDR on a particular network interface
Reset(cidr string) error
}

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pkg/util/bandwidth/linux.go Normal file
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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package bandwidth
import (
"bufio"
"bytes"
"encoding/hex"
"fmt"
"net"
"strings"
"k8s.io/kubernetes/pkg/api/resource"
"k8s.io/kubernetes/pkg/util"
"k8s.io/kubernetes/pkg/util/exec"
"github.com/golang/glog"
)
// tcShaper provides an implementation of the BandwidthShaper interface on Linux using the 'tc' tool.
// In general, using this requires that the caller posses the NET_CAP_ADMIN capability, though if you
// do this within an container, it only requires the NS_CAPABLE capability for manipulations to that
// container's network namespace.
// Uses the hierarchical token bucket queueing discipline (htb), this requires Linux 2.4.20 or newer
// or a custom kernel with that queueing discipline backported.
type tcShaper struct {
e exec.Interface
iface string
}
func NewTCShaper(iface string) BandwidthShaper {
shaper := &tcShaper{
e: exec.New(),
iface: iface,
}
shaper.initializeInterface()
return shaper
}
func (t *tcShaper) execAndLog(cmdStr string, args ...string) error {
glog.V(6).Infof("Running: %s %s", cmdStr, strings.Join(args, " "))
cmd := t.e.Command(cmdStr, args...)
out, err := cmd.CombinedOutput()
glog.V(6).Infof("Output from tc: %s", string(out))
return err
}
func (t *tcShaper) nextClassID() (int, error) {
data, err := t.e.Command("tc", "class", "show", "dev", t.iface).CombinedOutput()
if err != nil {
return -1, err
}
scanner := bufio.NewScanner(bytes.NewBuffer(data))
classes := util.StringSet{}
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
// skip empty lines
if len(line) == 0 {
continue
}
parts := strings.Split(line, " ")
// expected tc line:
// class htb 1:1 root prio 0 rate 1000Kbit ceil 1000Kbit burst 1600b cburst 1600b
if len(parts) != 14 {
return -1, fmt.Errorf("unexpected output from tc: %s (%v)", scanner.Text(), parts)
}
classes.Insert(parts[2])
}
// Make sure it doesn't go forever
for nextClass := 1; nextClass < 10000; nextClass++ {
if !classes.Has(fmt.Sprintf("1:%d", nextClass)) {
return nextClass, nil
}
}
// This should really never happen
return -1, fmt.Errorf("exhausted class space, please try again")
}
// Convert a CIDR from text to a hex representation
// Strips any masked parts of the IP, so 1.2.3.4/16 becomes hex(1.2.0.0)/ffffffff
func hexCIDR(cidr string) (string, error) {
ip, ipnet, err := net.ParseCIDR(cidr)
if err != nil {
return "", err
}
ip = ip.Mask(ipnet.Mask)
hexIP := hex.EncodeToString([]byte(ip.To4()))
hexMask := ipnet.Mask.String()
return hexIP + "/" + hexMask, nil
}
func (t *tcShaper) findCIDRClass(cidr string) (class, handle string, err error) {
data, err := t.e.Command("tc", "filter", "show", "dev", t.iface).CombinedOutput()
if err != nil {
return "", "", err
}
hex, err := hexCIDR(cidr)
if err != nil {
return "", "", err
}
spec := fmt.Sprintf("match %s", hex)
scanner := bufio.NewScanner(bytes.NewBuffer(data))
filter := ""
for scanner.Scan() {
line := strings.TrimSpace(scanner.Text())
if len(line) == 0 {
continue
}
if strings.HasPrefix(line, "filter") {
filter = line
continue
}
if strings.Contains(line, spec) {
parts := strings.Split(filter, " ")
// expected tc line:
// filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1
if len(parts) != 19 {
return "", "", fmt.Errorf("unexpected output from tc: %s %d (%v)", filter, len(parts), parts)
}
return parts[18], parts[9], nil
}
}
return "", "", fmt.Errorf("Failed to find cidr: %s on interface: %s", cidr, t.iface)
}
func makeKBitString(rsrc resource.Quantity) string {
return fmt.Sprintf("%dkbit", (rsrc.Value() / 1000))
}
func (t *tcShaper) makeNewClass(rate string) (int, error) {
class, err := t.nextClassID()
if err != nil {
return -1, err
}
if err := t.execAndLog("tc", "class", "add", "dev", t.iface, "parent", "1:", "classid", fmt.Sprintf("1:%d", class), "htb", "rate", rate); err != nil {
return -1, err
}
return class, nil
}
func (t *tcShaper) Limit(cidr string, upload, download resource.Quantity) (err error) {
var downloadClass, uploadClass int
if downloadClass, err = t.makeNewClass(makeKBitString(download)); err != nil {
return err
}
if uploadClass, err = t.makeNewClass(makeKBitString(upload)); err != nil {
return err
}
if err := t.execAndLog("tc", "filter", "add", "dev", t.iface, "protocol", "ip", "parent", "1:0", "prio", "1", "u32", "match", "ip", "dst", cidr, "flowid", fmt.Sprintf("1:%d", downloadClass)); err != nil {
return err
}
if err := t.execAndLog("tc", "filter", "add", "dev", t.iface, "protocol", "ip", "parent", "1:0", "prio", "1", "u32", "match", "ip", "src", cidr, "flowid", fmt.Sprintf("1:%d", uploadClass)); err != nil {
return err
}
return nil
}
func (t *tcShaper) initializeInterface() error {
return t.execAndLog("tc", "qdisc", "add", "dev", t.iface, "root", "handle", "1:", "htb", "default", "30")
}
func (t *tcShaper) Reset(cidr string) error {
class, handle, err := t.findCIDRClass(cidr)
if err != nil {
return err
}
if err := t.execAndLog("tc", "filter", "del", "dev", t.iface, "parent", "1:", "proto", "ip", "prio", "1", "handle", handle, "u32"); err != nil {
return err
}
return t.execAndLog("tc", "class", "del", "dev", t.iface, "parent", "1:", "classid", class)
}

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/*
Copyright 2015 The Kubernetes Authors All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package bandwidth
import (
"errors"
"testing"
"k8s.io/kubernetes/pkg/api/resource"
"k8s.io/kubernetes/pkg/util/exec"
)
var tcClassOutput = `class htb 1:1 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
class htb 1:2 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
class htb 1:3 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
class htb 1:4 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
`
var tcClassOutput2 = `class htb 1:1 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
class htb 1:2 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
class htb 1:3 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
class htb 1:4 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
class htb 1:5 root prio 0 rate 10000bit ceil 10000bit burst 1600b cburst 1600b
`
func TestNextClassID(t *testing.T) {
tests := []struct {
output string
expectErr bool
expected int
err error
}{
{
output: tcClassOutput,
expected: 5,
},
{
output: "\n",
expected: 1,
},
{
expected: -1,
expectErr: true,
err: errors.New("test error"),
},
}
for _, test := range tests {
fcmd := exec.FakeCmd{
CombinedOutputScript: []exec.FakeCombinedOutputAction{
func() ([]byte, error) { return []byte(test.output), test.err },
},
}
fexec := exec.FakeExec{
CommandScript: []exec.FakeCommandAction{
func(cmd string, args ...string) exec.Cmd {
return exec.InitFakeCmd(&fcmd, cmd, args...)
},
},
}
shaper := &tcShaper{e: &fexec}
class, err := shaper.nextClassID()
if test.expectErr {
if err == nil {
t.Errorf("unexpected non-error")
}
} else {
if err != nil {
t.Errorf("unexpected error: %v", err)
}
if class != test.expected {
t.Errorf("expected: %d, found %d", test.expected, class)
}
}
}
}
func TestHexCIDR(t *testing.T) {
tests := []struct {
input string
output string
expectErr bool
}{
{
input: "1.2.3.4/16",
output: "01020000/ffff0000",
},
{
input: "172.17.0.2/32",
output: "ac110002/ffffffff",
},
{
input: "foo",
expectErr: true,
},
}
for _, test := range tests {
output, err := hexCIDR(test.input)
if test.expectErr {
if err == nil {
t.Error("unexpected non-error")
}
} else {
if err != nil {
t.Errorf("unexpected error: %v", err)
}
if output != test.output {
t.Errorf("expected: %s, saw: %s", test.output, output)
}
}
}
}
var tcFilterOutput = `filter parent 1: protocol ip pref 1 u32
filter parent 1: protocol ip pref 1 u32 fh 800: ht divisor 1
filter parent 1: protocol ip pref 1 u32 fh 800::800 order 2048 key ht 800 bkt 0 flowid 1:1
match ac110002/ffffffff at 16
filter parent 1: protocol ip pref 1 u32 fh 800::801 order 2049 key ht 800 bkt 0 flowid 1:2
match 01020000/ffff0000 at 16
`
func TestFindCIDRClass(t *testing.T) {
tests := []struct {
cidr string
output string
expectErr bool
expectedClass string
expectedHandle string
err error
}{
{
cidr: "172.17.0.2/32",
output: tcFilterOutput,
expectedClass: "1:1",
expectedHandle: "800::800",
},
{
cidr: "1.2.3.4/16",
output: tcFilterOutput,
expectedClass: "1:2",
expectedHandle: "800::801",
},
{
err: errors.New("test error"),
expectErr: true,
},
}
for _, test := range tests {
fcmd := exec.FakeCmd{
CombinedOutputScript: []exec.FakeCombinedOutputAction{
func() ([]byte, error) { return []byte(test.output), test.err },
},
}
fexec := exec.FakeExec{
CommandScript: []exec.FakeCommandAction{
func(cmd string, args ...string) exec.Cmd {
return exec.InitFakeCmd(&fcmd, cmd, args...)
},
},
}
shaper := &tcShaper{e: &fexec}
class, handle, err := shaper.findCIDRClass(test.cidr)
if test.expectErr {
if err == nil {
t.Errorf("unexpected non-error")
}
} else {
if err != nil {
t.Errorf("unexpected error: %v", err)
}
if class != test.expectedClass {
t.Errorf("expected: %s, found %s", test.expectedClass, class)
}
if handle != test.expectedHandle {
t.Errorf("expected: %s, found %s", test.expectedHandle, handle)
}
}
}
}
func TestLimit(t *testing.T) {
tests := []struct {
cidr string
ingress *resource.Quantity
egress *resource.Quantity
expectErr bool
err error
}{
{
cidr: "1.2.3.4/32",
ingress: resource.NewQuantity(10, resource.DecimalSI),
egress: resource.NewQuantity(20, resource.DecimalSI),
},
{
err: errors.New("test error"),
ingress: resource.NewQuantity(10, resource.DecimalSI),
egress: resource.NewQuantity(20, resource.DecimalSI),
expectErr: true,
},
}
for _, test := range tests {
fcmd := exec.FakeCmd{
CombinedOutputScript: []exec.FakeCombinedOutputAction{
func() ([]byte, error) { return []byte(tcClassOutput), test.err },
func() ([]byte, error) { return []byte{}, test.err },
func() ([]byte, error) { return []byte(tcClassOutput2), test.err },
func() ([]byte, error) { return []byte{}, test.err },
func() ([]byte, error) { return []byte{}, test.err },
func() ([]byte, error) { return []byte{}, test.err },
},
}
fexec := exec.FakeExec{
CommandScript: []exec.FakeCommandAction{
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
},
}
iface := "cbr0"
shaper := &tcShaper{e: &fexec, iface: iface}
if err := shaper.Limit(test.cidr, *test.ingress, *test.egress); err != nil && !test.expectErr {
t.Errorf("unexpected error: %v", err)
return
} else if err == nil && test.expectErr {
t.Error("unexpected non-error")
return
}
// No more testing in the error case
if test.expectErr {
if fcmd.CombinedOutputCalls != 1 {
t.Errorf("unexpected number of calls: %d, expected: 1", fcmd.CombinedOutputCalls)
}
return
}
if fcmd.CombinedOutputCalls != 6 {
t.Errorf("unexpected number of calls: %d, expected: 6", fcmd.CombinedOutputCalls)
}
for ix := range fcmd.CombinedOutputLog {
output := fcmd.CombinedOutputLog[ix]
if output[0] != "tc" {
t.Errorf("unexpected command: %s, expected tc", output[0])
}
if output[4] != iface {
t.Errorf("unexpected interface: %s, expected %s (%v)", output[4], iface, output)
}
if ix == 1 {
if output[11] != makeKBitString(*test.ingress) {
t.Errorf("unexpected ingress: %s, expected: %s", output[11], makeKBitString(*test.ingress))
}
if output[8] != "1:5" {
t.Errorf("unexpected class: %s, expected: %s", output[8], "1:5")
}
}
if ix == 3 {
if output[11] != makeKBitString(*test.egress) {
t.Errorf("unexpected egress: %s, expected: %s", output[11], makeKBitString(*test.egress))
}
if output[8] != "1:6" {
t.Errorf("unexpected class: %s, expected: %s", output[8], "1:6")
}
}
if ix == 4 {
if output[15] != test.cidr {
t.Errorf("unexpected cidr: %s, expected: %s", output[15], test.cidr)
}
if output[17] != "1:5" {
t.Errorf("unexpected class: %s, expected: %s", output[17], "1:5")
}
}
if ix == 5 {
if output[15] != test.cidr {
t.Errorf("unexpected cidr: %s, expected: %s", output[15], test.cidr)
}
if output[17] != "1:6" {
t.Errorf("unexpected class: %s, expected: %s", output[17], "1:5")
}
}
}
}
}
func TestReset(t *testing.T) {
tests := []struct {
cidr string
err error
expectErr bool
expectedHandle string
expectedClass string
}{
{
cidr: "1.2.3.4/16",
expectedHandle: "800::801",
expectedClass: "1:2",
},
{
cidr: "172.17.0.2/32",
expectedHandle: "800::800",
expectedClass: "1:1",
},
{
err: errors.New("test error"),
expectErr: true,
},
}
for _, test := range tests {
fcmd := exec.FakeCmd{
CombinedOutputScript: []exec.FakeCombinedOutputAction{
func() ([]byte, error) { return []byte(tcFilterOutput), test.err },
func() ([]byte, error) { return []byte{}, test.err },
func() ([]byte, error) { return []byte{}, test.err },
},
}
fexec := exec.FakeExec{
CommandScript: []exec.FakeCommandAction{
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
func(cmd string, args ...string) exec.Cmd { return exec.InitFakeCmd(&fcmd, cmd, args...) },
},
}
iface := "cbr0"
shaper := &tcShaper{e: &fexec, iface: iface}
if err := shaper.Reset(test.cidr); err != nil && !test.expectErr {
t.Errorf("unexpected error: %v", err)
return
} else if test.expectErr && err == nil {
t.Error("unexpected non-error")
return
}
// No more testing in the error case
if test.expectErr {
if fcmd.CombinedOutputCalls != 1 {
t.Errorf("unexpected number of calls: %d, expected: 1", fcmd.CombinedOutputCalls)
}
return
}
if fcmd.CombinedOutputCalls != 3 {
t.Errorf("unexpected number of calls: %d, expected: 3", fcmd.CombinedOutputCalls)
}
for ix := range fcmd.CombinedOutputLog {
output := fcmd.CombinedOutputLog[ix]
if output[0] != "tc" {
t.Errorf("unexpected command: %s, expected tc", output[0])
}
if output[4] != iface {
t.Errorf("unexpected interface: %s, expected %s (%v)", output[4], iface, output)
}
if ix == 1 && output[12] != test.expectedHandle {
t.Errorf("unexpected handle: %s, expected: %s", output[12], test.expectedHandle)
}
if ix == 2 && output[8] != test.expectedClass {
t.Errorf("unexpected class: %s, expected: %s", output[8], test.expectedClass)
}
}
}
}