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Rate limiting for frontends

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Ben Parli 2017-09-09 04:36:03 -07:00 committed by Traefiker
parent 9fba37b409
commit d54417acfe
16 changed files with 1410 additions and 3 deletions
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29
docs/basics.md
View file

@ -292,6 +292,35 @@ In this example, traffic routed through the first frontend will have the `X-Fram
The detailed documentation for those security headers can be found in [unrolled/secure](https://github.com/unrolled/secure#available-options).
#### Rate limiting
Rate limiting can be configured per frontend.
Multiple sets of rates can be added to each frontend, but the time periods must be unique.
```toml
[frontends]
[frontends.frontend1]
passHostHeader = true
entrypoints = ["http"]
backend = "backend1"
[frontends.frontend1.routes.test_1]
rule = "Path:/"
[frontends.frontend1.ratelimit]
extractorfunc = "client.ip"
[frontends.frontend1.ratelimit.rateset.rateset1]
period = "10s"
average = 100
burst = 200
[frontends.frontend1.ratelimit.rateset.rateset2]
period = "3s"
average = 5
burst = 10
```
In the above example, frontend1 is configured to limit requests by the client's ip address.
An average of 5 requests every 3 seconds is allowed and an average of 100 requests every 10 seconds.
These can "burst" up to 10 and 200 in each period respectively.
### Backends
A backend is responsible to load-balance the traffic coming from one or more frontends to a set of http servers.

9
glide.lock generated
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@ -1,5 +1,5 @@
hash: c5a62552734b2e283ebedf94e6b711e7efa47d2b1b80f3dda6ca923317fef3c2
updated: 2017-08-25T11:52:16.848940186+02:00
hash: 857714f15cc10657ae2f15f3ab6592734a1ebc524d32b5353948258ce3043b6a
updated: 2017-09-09T11:52:16.848940186+02:00
imports:
- name: cloud.google.com/go
version: 2e6a95edb1071d750f6d7db777bf66cd2997af6c
@ -320,8 +320,12 @@ imports:
version: 77ed1c8a01217656d2080ad51981f6e99adaa177
- name: github.com/kr/logfmt
version: b84e30acd515aadc4b783ad4ff83aff3299bdfe0
- name: github.com/mailgun/minheap
version: 7c28d80e2ada649fc8ab1a37b86d30a2633bd47c
- name: github.com/mailgun/timetools
version: 7e6055773c5137efbeb3bd2410d705fe10ab6bfd
- name: github.com/mailgun/ttlmap
version: c1c17f74874f2a5ea48bfb06b5459d4ef2689749
- name: github.com/mailru/easyjson
version: d5b7844b561a7bc640052f1b935f7b800330d7e0
subpackages:
@ -487,6 +491,7 @@ imports:
- connlimit
- forward
- memmetrics
- ratelimit
- roundrobin
- stream
- utils

3
glide.yaml
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@ -22,6 +22,7 @@ import:
- roundrobin
- stream
- utils
- ratelimit
- package: github.com/urfave/negroni
version: 490e6a555d47ca891a89a150d0c1ef3922dfffe9
- package: github.com/containous/staert
@ -79,9 +80,9 @@ import:
vcs: git
- package: github.com/abbot/go-http-auth
- package: github.com/NYTimes/gziphandler
version: ^v1002.0.0
repo: https://github.com/containous/gziphandler.git
vcs: git
version: ^v1002.0.0
- package: github.com/docker/leadership
- package: github.com/satori/go.uuid
version: ^1.1.0

30
integration/fixtures/ratelimit/simple.toml Normal file
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@ -0,0 +1,30 @@
defaultEntryPoints = ["http"]
logLevel = "DEBUG"
[entryPoints]
[entryPoints.http]
address = ":80"
[file]
[backends]
[backends.backend1]
[backends.backend1.servers.server1]
url = "http://{{.Server1}}:80"
[frontends]
[frontends.frontend1]
passHostHeader = true
backend = "backend1"
[frontends.frontend1.routes.test_1]
rule = "Path:/"
[frontends.frontend1.ratelimit]
extractorfunc = "client.ip"
[frontends.frontend1.ratelimit.rateset.rateset1]
period = "60s"
average = 4
burst = 5
[frontends.frontend1.ratelimit.rateset.rateset2]
period = "3s"
average = 1
burst = 2

1
integration/integration_test.go
View file

@ -39,6 +39,7 @@ func init() {
check.Suite(&LogRotationSuite{})
check.Suite(&MarathonSuite{})
check.Suite(&MesosSuite{})
check.Suite(&RateLimitSuite{})
check.Suite(&SimpleSuite{})
check.Suite(&TimeoutSuite{})
check.Suite(&WebsocketSuite{})

61
integration/ratelimit_test.go Normal file
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@ -0,0 +1,61 @@
package integration
import (
"net/http"
"os"
"time"
"github.com/containous/traefik/integration/try"
"github.com/go-check/check"
checker "github.com/vdemeester/shakers"
)
type RateLimitSuite struct {
BaseSuite
ServerIP string
}
func (s *RateLimitSuite) SetUpSuite(c *check.C) {
s.createComposeProject(c, "ratelimit")
s.composeProject.Start(c)
s.ServerIP = s.composeProject.Container(c, "nginx1").NetworkSettings.IPAddress
}
func (s *RateLimitSuite) TestSimpleConfiguration(c *check.C) {
file := s.adaptFile(c, "fixtures/ratelimit/simple.toml", struct {
Server1 string
}{s.ServerIP})
defer os.Remove(file)
cmd, _ := s.cmdTraefik(withConfigFile(file))
err := cmd.Start()
c.Assert(err, checker.IsNil)
defer cmd.Process.Kill()
err = try.GetRequest("http://127.0.0.1:80/", 500*time.Millisecond, try.StatusCodeIs(http.StatusOK))
c.Assert(err, checker.IsNil)
err = try.GetRequest("http://127.0.0.1:80/", 500*time.Millisecond, try.StatusCodeIs(http.StatusOK))
c.Assert(err, checker.IsNil)
err = try.GetRequest("http://127.0.0.1:80/", 500*time.Millisecond, try.StatusCodeIs(http.StatusTooManyRequests))
c.Assert(err, checker.IsNil)
// sleep for 4 seconds to be certain the configured time period has elapsed
// then test another request and verify a 200 status code
time.Sleep(4 * time.Second)
err = try.GetRequest("http://127.0.0.1:80/", 500*time.Millisecond, try.StatusCodeIs(http.StatusOK))
c.Assert(err, checker.IsNil)
// continue requests at 3 second intervals to test the other rate limit time period
time.Sleep(3 * time.Second)
err = try.GetRequest("http://127.0.0.1:80/", 500*time.Millisecond, try.StatusCodeIs(http.StatusOK))
c.Assert(err, checker.IsNil)
time.Sleep(3 * time.Second)
err = try.GetRequest("http://127.0.0.1:80/", 500*time.Millisecond, try.StatusCodeIs(http.StatusOK))
c.Assert(err, checker.IsNil)
time.Sleep(3 * time.Second)
err = try.GetRequest("http://127.0.0.1:80/", 500*time.Millisecond, try.StatusCodeIs(http.StatusTooManyRequests))
c.Assert(err, checker.IsNil)
}

2
integration/resources/compose/ratelimit.yml Normal file
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@ -0,0 +1,2 @@
nginx1:
image: nginx:alpine

25
server/server.go
View file

@ -36,6 +36,7 @@ import (
"github.com/vulcand/oxy/cbreaker"
"github.com/vulcand/oxy/connlimit"
"github.com/vulcand/oxy/forward"
"github.com/vulcand/oxy/ratelimit"
"github.com/vulcand/oxy/roundrobin"
"github.com/vulcand/oxy/utils"
"golang.org/x/net/http2"
@ -891,6 +892,15 @@ func (server *Server) loadConfig(configurations types.Configurations, globalConf
}
}
if frontend.RateLimit != nil && len(frontend.RateLimit.RateSet) > 0 {
lb, err = server.buildRateLimiter(lb, frontend.RateLimit)
if err != nil {
log.Errorf("Error creating rate limiter: %v", err)
log.Errorf("Skipping frontend %s...", frontendName)
continue frontend
}
}
maxConns := config.Backends[frontend.Backend].MaxConn
if maxConns != nil && maxConns.Amount != 0 {
extractFunc, err := utils.NewExtractor(maxConns.ExtractorFunc)
@ -1189,6 +1199,21 @@ func stopMetricsClients() {
metrics.StopStatsd()
}
func (server *Server) buildRateLimiter(handler http.Handler, rlConfig *types.RateLimit) (http.Handler, error) {
extractFunc, err := utils.NewExtractor(rlConfig.ExtractorFunc)
if err != nil {
return nil, err
}
log.Debugf("Creating load-balancer rate limiter")
rateSet := ratelimit.NewRateSet()
for _, rate := range rlConfig.RateSet {
if err := rateSet.Add(time.Duration(rate.Period), rate.Average, rate.Burst); err != nil {
return nil, err
}
}
return ratelimit.New(handler, extractFunc, rateSet, ratelimit.Logger(oxyLogger))
}
func (server *Server) buildRetryMiddleware(handler http.Handler, globalConfig configuration.GlobalConfiguration, countServers int, backendName string) http.Handler {
retryListeners := middlewares.RetryListeners{}
if server.metricsRegistry.IsEnabled() {

15
types/types.go
View file

@ -12,6 +12,7 @@ import (
"io/ioutil"
"os"
"github.com/containous/flaeg"
"github.com/containous/traefik/log"
"github.com/docker/libkv/store"
"github.com/ryanuber/go-glob"
@ -67,6 +68,19 @@ type ErrorPage struct {
Query string `json:"query,omitempty"`
}
// Rate holds a rate limiting configuration for a specific time period
type Rate struct {
Period flaeg.Duration `json:"period,omitempty"`
Average int64 `json:"average,omitempty"`
Burst int64 `json:"burst,omitempty"`
}
// RateLimit holds a rate limiting configuration for a given frontend
type RateLimit struct {
RateSet map[string]*Rate `json:"rateset,omitempty"`
ExtractorFunc string `json:"extractorFunc,omitempty"`
}
// Headers holds the custom header configuration
type Headers struct {
CustomRequestHeaders map[string]string `json:"customRequestHeaders,omitempty"`
@ -131,6 +145,7 @@ type Frontend struct {
WhitelistSourceRange []string `json:"whitelistSourceRange,omitempty"`
Headers Headers `json:"headers,omitempty"`
Errors map[string]ErrorPage `json:"errors,omitempty"`
RateLimit *RateLimit `json:"ratelimit,omitempty"`
}
// LoadBalancerMethod holds the method of load balancing to use.

202
vendor/github.com/mailgun/minheap/LICENSE generated vendored Normal file
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@ -0,0 +1,202 @@
Apache License
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http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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To apply the Apache License to your work, attach the following
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75
vendor/github.com/mailgun/minheap/minheap.go generated vendored Normal file
View file

@ -0,0 +1,75 @@
package minheap
import (
"container/heap"
)
// An Element is something we manage in a priority queue.
type Element struct {
Value interface{}
Priority int // The priority of the item in the queue.
// The index is needed by update and is maintained by the heap.Interface methods.
index int // The index of the item in the heap.
}
// A PriorityQueue implements heap.Interface and holds Items.
type MinHeap []*Element
func NewMinHeap() *MinHeap {
mh := &MinHeap{}
heap.Init(mh)
return mh
}
func (mh MinHeap) Len() int { return len(mh) }
func (mh MinHeap) Less(i, j int) bool {
return mh[i].Priority < mh[j].Priority
}
func (mh MinHeap) Swap(i, j int) {
mh[i], mh[j] = mh[j], mh[i]
mh[i].index = i
mh[j].index = j
}
func (mh *MinHeap) Push(x interface{}) {
n := len(*mh)
item := x.(*Element)
item.index = n
*mh = append(*mh, item)
}
func (mh *MinHeap) Pop() interface{} {
old := *mh
n := len(old)
item := old[n-1]
item.index = -1 // for safety
*mh = old[0 : n-1]
return item
}
func (mh *MinHeap) PushEl(el *Element) {
heap.Push(mh, el)
}
func (mh *MinHeap) PopEl() *Element {
el := heap.Pop(mh)
return el.(*Element)
}
func (mh *MinHeap) PeekEl() *Element {
items := *mh
return items[0]
}
// update modifies the priority and value of an Item in the queue.
func (mh *MinHeap) UpdateEl(el *Element, priority int) {
heap.Remove(mh, el.index)
el.Priority = priority
heap.Push(mh, el)
}
func (mh *MinHeap) RemoveEl(el *Element) {
heap.Remove(mh, el.index)
}

202
vendor/github.com/mailgun/ttlmap/LICENSE generated vendored Normal file
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@ -0,0 +1,202 @@
Apache License
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http://www.apache.org/licenses/
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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"License" shall mean the terms and conditions for use, reproduction,
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outstanding shares, or (iii) beneficial ownership of such entity.
"You" (or "Your") shall mean an individual or Legal Entity
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"Source" form shall mean the preferred form for making modifications,
including but not limited to software source code, documentation
source, and configuration files.
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not limited to compiled object code, generated documentation,
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278
vendor/github.com/mailgun/ttlmap/ttlmap.go generated vendored Normal file
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package ttlmap
import (
"errors"
"fmt"
"sync"
"time"
"github.com/mailgun/minheap"
"github.com/mailgun/timetools"
)
type TtlMapOption func(m *TtlMap) error
// Clock sets the time provider clock, handy for testing
func Clock(c timetools.TimeProvider) TtlMapOption {
return func(m *TtlMap) error {
m.clock = c
return nil
}
}
type Callback func(key string, el interface{})
// CallOnExpire will call this callback on expiration of elements
func CallOnExpire(cb Callback) TtlMapOption {
return func(m *TtlMap) error {
m.onExpire = cb
return nil
}
}
type TtlMap struct {
capacity int
elements map[string]*mapElement
expiryTimes *minheap.MinHeap
clock timetools.TimeProvider
mutex *sync.RWMutex
// onExpire callback will be called when element is expired
onExpire Callback
}
type mapElement struct {
key string
value interface{}
heapEl *minheap.Element
}
func NewMap(capacity int, opts ...TtlMapOption) (*TtlMap, error) {
if capacity <= 0 {
return nil, errors.New("Capacity should be > 0")
}
m := &TtlMap{
capacity: capacity,
elements: make(map[string]*mapElement),
expiryTimes: minheap.NewMinHeap(),
}
for _, o := range opts {
if err := o(m); err != nil {
return nil, err
}
}
if m.clock == nil {
m.clock = &timetools.RealTime{}
}
return m, nil
}
func NewMapWithProvider(capacity int, timeProvider timetools.TimeProvider) (*TtlMap, error) {
if timeProvider == nil {
return nil, errors.New("Please pass timeProvider")
}
return NewMap(capacity, Clock(timeProvider))
}
func NewConcurrent(capacity int, opts ...TtlMapOption) (*TtlMap, error) {
m, err := NewMap(capacity, opts...)
if err == nil {
m.mutex = new(sync.RWMutex)
}
return m, err
}
func (m *TtlMap) Set(key string, value interface{}, ttlSeconds int) error {
expiryTime, err := m.toEpochSeconds(ttlSeconds)
if err != nil {
return err
}
if m.mutex != nil {
m.mutex.Lock()
defer m.mutex.Unlock()
}
return m.set(key, value, expiryTime)
}
func (m *TtlMap) Len() int {
if m.mutex != nil {
m.mutex.RLock()
defer m.mutex.RUnlock()
}
return len(m.elements)
}
func (m *TtlMap) Get(key string) (interface{}, bool) {
value, mapEl, expired := m.lockNGet(key)
if mapEl == nil {
return nil, false
}
if expired {
m.lockNDel(mapEl)
return nil, false
}
return value, true
}
func (m *TtlMap) Increment(key string, value int, ttlSeconds int) (int, error) {
expiryTime, err := m.toEpochSeconds(ttlSeconds)
if err != nil {
return 0, err
}
if m.mutex != nil {
m.mutex.Lock()
defer m.mutex.Unlock()
}
mapEl, expired := m.get(key)
if mapEl == nil || expired {
m.set(key, value, expiryTime)
return value, nil
}
currentValue, ok := mapEl.value.(int)
if !ok {
return 0, fmt.Errorf("Expected existing value to be integer, got %T", mapEl.value)
}
currentValue += value
m.set(key, currentValue, expiryTime)
return currentValue, nil
}
func (m *TtlMap) GetInt(key string) (int, bool, error) {
valueI, exists := m.Get(key)
if !exists {
return 0, false, nil
}
value, ok := valueI.(int)
if !ok {
return 0, false, fmt.Errorf("Expected existing value to be integer, got %T", valueI)
}
return value, true, nil
}
func (m *TtlMap) set(key string, value interface{}, expiryTime int) error {
if mapEl, ok := m.elements[key]; ok {
mapEl.value = value
m.expiryTimes.UpdateEl(mapEl.heapEl, expiryTime)
return nil
}
if len(m.elements) >= m.capacity {
m.freeSpace(1)
}
heapEl := &minheap.Element{
Priority: expiryTime,
}
mapEl := &mapElement{
key: key,
value: value,
heapEl: heapEl,
}
heapEl.Value = mapEl
m.elements[key] = mapEl
m.expiryTimes.PushEl(heapEl)
return nil
}
func (m *TtlMap) lockNGet(key string) (value interface{}, mapEl *mapElement, expired bool) {
if m.mutex != nil {
m.mutex.RLock()
defer m.mutex.RUnlock()
}
mapEl, expired = m.get(key)
value = nil
if mapEl != nil {
value = mapEl.value
}
return value, mapEl, expired
}
func (m *TtlMap) get(key string) (*mapElement, bool) {
mapEl, ok := m.elements[key]
if !ok {
return nil, false
}
now := int(m.clock.UtcNow().Unix())
expired := mapEl.heapEl.Priority <= now
return mapEl, expired
}
func (m *TtlMap) lockNDel(mapEl *mapElement) {
if m.mutex != nil {
m.mutex.Lock()
defer m.mutex.Unlock()
// Map element could have been updated. Now that we have a lock
// retrieve it again and check if it is still expired.
var ok bool
if mapEl, ok = m.elements[mapEl.key]; !ok {
return
}
now := int(m.clock.UtcNow().Unix())
if mapEl.heapEl.Priority > now {
return
}
}
m.del(mapEl)
}
func (m *TtlMap) del(mapEl *mapElement) {
if m.onExpire != nil {
m.onExpire(mapEl.key, mapEl.value)
}
delete(m.elements, mapEl.key)
m.expiryTimes.RemoveEl(mapEl.heapEl)
}
func (m *TtlMap) freeSpace(count int) {
removed := m.removeExpired(count)
if removed >= count {
return
}
m.removeLastUsed(count - removed)
}
func (m *TtlMap) removeExpired(iterations int) int {
removed := 0
now := int(m.clock.UtcNow().Unix())
for i := 0; i < iterations; i += 1 {
if len(m.elements) == 0 {
break
}
heapEl := m.expiryTimes.PeekEl()
if heapEl.Priority > now {
break
}
m.expiryTimes.PopEl()
mapEl := heapEl.Value.(*mapElement)
delete(m.elements, mapEl.key)
removed += 1
}
return removed
}
func (m *TtlMap) removeLastUsed(iterations int) {
for i := 0; i < iterations; i += 1 {
if len(m.elements) == 0 {
return
}
heapEl := m.expiryTimes.PopEl()
mapEl := heapEl.Value.(*mapElement)
delete(m.elements, mapEl.key)
}
}
func (m *TtlMap) toEpochSeconds(ttlSeconds int) (int, error) {
if ttlSeconds <= 0 {
return 0, fmt.Errorf("ttlSeconds should be >= 0, got %d", ttlSeconds)
}
return int(m.clock.UtcNow().Add(time.Second * time.Duration(ttlSeconds)).Unix()), nil
}

125
vendor/github.com/vulcand/oxy/ratelimit/bucket.go generated vendored Normal file
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package ratelimit
import (
"fmt"
"time"
"github.com/mailgun/timetools"
)
const UndefinedDelay = -1
// rate defines token bucket parameters.
type rate struct {
period time.Duration
average int64
burst int64
}
func (r *rate) String() string {
return fmt.Sprintf("rate(%v/%v, burst=%v)", r.average, r.period, r.burst)
}
// Implements token bucket algorithm (http://en.wikipedia.org/wiki/Token_bucket)
type tokenBucket struct {
// The time period controlled by the bucket in nanoseconds.
period time.Duration
// The number of nanoseconds that takes to add one more token to the total
// number of available tokens. It effectively caches the value that could
// have been otherwise deduced from refillRate.
timePerToken time.Duration
// The maximum number of tokens that can be accumulate in the bucket.
burst int64
// The number of tokens available for consumption at the moment. It can
// nether be larger then capacity.
availableTokens int64
// Interface that gives current time (so tests can override)
clock timetools.TimeProvider
// Tells when tokensAvailable was updated the last time.
lastRefresh time.Time
// The number of tokens consumed the last time.
lastConsumed int64
}
// newTokenBucket crates a `tokenBucket` instance for the specified `Rate`.
func newTokenBucket(rate *rate, clock timetools.TimeProvider) *tokenBucket {
return &tokenBucket{
period: rate.period,
timePerToken: time.Duration(int64(rate.period) / rate.average),
burst: rate.burst,
clock: clock,
lastRefresh: clock.UtcNow(),
availableTokens: rate.burst,
}
}
// consume makes an attempt to consume the specified number of tokens from the
// bucket. If there are enough tokens available then `0, nil` is returned; if
// tokens to consume is larger than the burst size, then an error is returned
// and the delay is not defined; otherwise returned a none zero delay that tells
// how much time the caller needs to wait until the desired number of tokens
// will become available for consumption.
func (tb *tokenBucket) consume(tokens int64) (time.Duration, error) {
tb.updateAvailableTokens()
tb.lastConsumed = 0
if tokens > tb.burst {
return UndefinedDelay, fmt.Errorf("Requested tokens larger than max tokens")
}
if tb.availableTokens < tokens {
return tb.timeTillAvailable(tokens), nil
}
tb.availableTokens -= tokens
tb.lastConsumed = tokens
return 0, nil
}
// rollback reverts effect of the most recent consumption. If the most recent
// `consume` resulted in an error or a burst overflow, and therefore did not
// modify the number of available tokens, then `rollback` won't do that either.
// It is safe to call this method multiple times, for the second and all
// following calls have no effect.
func (tb *tokenBucket) rollback() {
tb.availableTokens += tb.lastConsumed
tb.lastConsumed = 0
}
// Update modifies `average` and `burst` fields of the token bucket according
// to the provided `Rate`
func (tb *tokenBucket) update(rate *rate) error {
if rate.period != tb.period {
return fmt.Errorf("Period mismatch: %v != %v", tb.period, rate.period)
}
tb.timePerToken = time.Duration(int64(tb.period) / rate.average)
tb.burst = rate.burst
if tb.availableTokens > rate.burst {
tb.availableTokens = rate.burst
}
return nil
}
// timeTillAvailable returns the number of nanoseconds that we need to
// wait until the specified number of tokens becomes available for consumption.
func (tb *tokenBucket) timeTillAvailable(tokens int64) time.Duration {
missingTokens := tokens - tb.availableTokens
return time.Duration(missingTokens) * tb.timePerToken
}
// updateAvailableTokens updates the number of tokens available for consumption.
// It is calculated based on the refill rate, the time passed since last refresh,
// and is limited by the bucket capacity.
func (tb *tokenBucket) updateAvailableTokens() {
now := tb.clock.UtcNow()
timePassed := now.Sub(tb.lastRefresh)
tokens := tb.availableTokens + int64(timePassed/tb.timePerToken)
// If we haven't added any tokens that means that not enough time has passed,
// in this case do not adjust last refill checkpoint, otherwise it will be
// always moving in time in case of frequent requests that exceed the rate
if tokens != tb.availableTokens {
tb.lastRefresh = now
tb.availableTokens = tokens
}
if tb.availableTokens > tb.burst {
tb.availableTokens = tb.burst
}
}

108
vendor/github.com/vulcand/oxy/ratelimit/bucketset.go generated vendored Normal file
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package ratelimit
import (
"fmt"
"strings"
"time"
"github.com/mailgun/timetools"
"sort"
)
// TokenBucketSet represents a set of TokenBucket covering different time periods.
type TokenBucketSet struct {
buckets map[time.Duration]*tokenBucket
maxPeriod time.Duration
clock timetools.TimeProvider
}
// newTokenBucketSet creates a `TokenBucketSet` from the specified `rates`.
func NewTokenBucketSet(rates *RateSet, clock timetools.TimeProvider) *TokenBucketSet {
tbs := new(TokenBucketSet)
tbs.clock = clock
// In the majority of cases we will have only one bucket.
tbs.buckets = make(map[time.Duration]*tokenBucket, len(rates.m))
for _, rate := range rates.m {
newBucket := newTokenBucket(rate, clock)
tbs.buckets[rate.period] = newBucket
tbs.maxPeriod = maxDuration(tbs.maxPeriod, rate.period)
}
return tbs
}
// Update brings the buckets in the set in accordance with the provided `rates`.
func (tbs *TokenBucketSet) Update(rates *RateSet) {
// Update existing buckets and delete those that have no corresponding spec.
for _, bucket := range tbs.buckets {
if rate, ok := rates.m[bucket.period]; ok {
bucket.update(rate)
} else {
delete(tbs.buckets, bucket.period)
}
}
// Add missing buckets.
for _, rate := range rates.m {
if _, ok := tbs.buckets[rate.period]; !ok {
newBucket := newTokenBucket(rate, tbs.clock)
tbs.buckets[rate.period] = newBucket
}
}
// Identify the maximum period in the set
tbs.maxPeriod = 0
for _, bucket := range tbs.buckets {
tbs.maxPeriod = maxDuration(tbs.maxPeriod, bucket.period)
}
}
func (tbs *TokenBucketSet) Consume(tokens int64) (time.Duration, error) {
var maxDelay time.Duration = UndefinedDelay
var firstErr error = nil
for _, tokenBucket := range tbs.buckets {
// We keep calling `Consume` even after a error is returned for one of
// buckets because that allows us to simplify the rollback procedure,
// that is to just call `Rollback` for all buckets.
delay, err := tokenBucket.consume(tokens)
if firstErr == nil {
if err != nil {
firstErr = err
} else {
maxDelay = maxDuration(maxDelay, delay)
}
}
}
// If we could not make ALL buckets consume tokens for whatever reason,
// then rollback consumption for all of them.
if firstErr != nil || maxDelay > 0 {
for _, tokenBucket := range tbs.buckets {
tokenBucket.rollback()
}
}
return maxDelay, firstErr
}
func (tbs *TokenBucketSet) GetMaxPeriod() time.Duration {
return tbs.maxPeriod
}
// debugState returns string that reflects the current state of all buckets in
// this set. It is intended to be used for debugging and testing only.
func (tbs *TokenBucketSet) debugState() string {
periods := sort.IntSlice(make([]int, 0, len(tbs.buckets)))
for period := range tbs.buckets {
periods = append(periods, int(period))
}
sort.Sort(periods)
bucketRepr := make([]string, 0, len(tbs.buckets))
for _, period := range periods {
bucket := tbs.buckets[time.Duration(period)]
bucketRepr = append(bucketRepr, fmt.Sprintf("{%v: %v}", bucket.period, bucket.availableTokens))
}
return strings.Join(bucketRepr, ", ")
}
func maxDuration(x time.Duration, y time.Duration) time.Duration {
if x > y {
return x
}
return y
}

248
vendor/github.com/vulcand/oxy/ratelimit/tokenlimiter.go generated vendored Normal file
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// Tokenbucket based request rate limiter
package ratelimit
import (
"fmt"
"net/http"
"sync"
"time"
"github.com/mailgun/timetools"
"github.com/mailgun/ttlmap"
"github.com/vulcand/oxy/utils"
)
const DefaultCapacity = 65536
// RateSet maintains a set of rates. It can contain only one rate per period at a time.
type RateSet struct {
m map[time.Duration]*rate
}
// NewRateSet crates an empty `RateSet` instance.
func NewRateSet() *RateSet {
rs := new(RateSet)
rs.m = make(map[time.Duration]*rate)
return rs
}
// Add adds a rate to the set. If there is a rate with the same period in the
// set then the new rate overrides the old one.
func (rs *RateSet) Add(period time.Duration, average int64, burst int64) error {
if period <= 0 {
return fmt.Errorf("Invalid period: %v", period)
}
if average <= 0 {
return fmt.Errorf("Invalid average: %v", average)
}
if burst <= 0 {
return fmt.Errorf("Invalid burst: %v", burst)
}
rs.m[period] = &rate{period, average, burst}
return nil
}
func (rs *RateSet) String() string {
return fmt.Sprint(rs.m)
}
type RateExtractor interface {
Extract(r *http.Request) (*RateSet, error)
}
type RateExtractorFunc func(r *http.Request) (*RateSet, error)
func (e RateExtractorFunc) Extract(r *http.Request) (*RateSet, error) {
return e(r)
}
// TokenLimiter implements rate limiting middleware.
type TokenLimiter struct {
defaultRates *RateSet
extract utils.SourceExtractor
extractRates RateExtractor
clock timetools.TimeProvider
mutex sync.Mutex
bucketSets *ttlmap.TtlMap
errHandler utils.ErrorHandler
log utils.Logger
capacity int
next http.Handler
}
// New constructs a `TokenLimiter` middleware instance.
func New(next http.Handler, extract utils.SourceExtractor, defaultRates *RateSet, opts ...TokenLimiterOption) (*TokenLimiter, error) {
if defaultRates == nil || len(defaultRates.m) == 0 {
return nil, fmt.Errorf("Provide default rates")
}
if extract == nil {
return nil, fmt.Errorf("Provide extract function")
}
tl := &TokenLimiter{
next: next,
defaultRates: defaultRates,
extract: extract,
}
for _, o := range opts {
if err := o(tl); err != nil {
return nil, err
}
}
setDefaults(tl)
bucketSets, err := ttlmap.NewMapWithProvider(tl.capacity, tl.clock)
if err != nil {
return nil, err
}
tl.bucketSets = bucketSets
return tl, nil
}
func (tl *TokenLimiter) Wrap(next http.Handler) {
tl.next = next
}
func (tl *TokenLimiter) ServeHTTP(w http.ResponseWriter, req *http.Request) {
source, amount, err := tl.extract.Extract(req)
if err != nil {
tl.errHandler.ServeHTTP(w, req, err)
return
}
if err := tl.consumeRates(req, source, amount); err != nil {
tl.log.Infof("limiting request %v %v, limit: %v", req.Method, req.URL, err)
tl.errHandler.ServeHTTP(w, req, err)
return
}
tl.next.ServeHTTP(w, req)
}
func (tl *TokenLimiter) consumeRates(req *http.Request, source string, amount int64) error {
tl.mutex.Lock()
defer tl.mutex.Unlock()
effectiveRates := tl.resolveRates(req)
bucketSetI, exists := tl.bucketSets.Get(source)
var bucketSet *TokenBucketSet
if exists {
bucketSet = bucketSetI.(*TokenBucketSet)
bucketSet.Update(effectiveRates)
} else {
bucketSet = NewTokenBucketSet(effectiveRates, tl.clock)
// We set ttl as 10 times rate period. E.g. if rate is 100 requests/second per client ip
// the counters for this ip will expire after 10 seconds of inactivity
tl.bucketSets.Set(source, bucketSet, int(bucketSet.maxPeriod/time.Second)*10+1)
}
delay, err := bucketSet.Consume(amount)
if err != nil {
return err
}
if delay > 0 {
return &MaxRateError{delay: delay}
}
return nil
}
// effectiveRates retrieves rates to be applied to the request.
func (tl *TokenLimiter) resolveRates(req *http.Request) *RateSet {
// If configuration mapper is not specified for this instance, then return
// the default bucket specs.
if tl.extractRates == nil {
return tl.defaultRates
}
rates, err := tl.extractRates.Extract(req)
if err != nil {
tl.log.Errorf("Failed to retrieve rates: %v", err)
return tl.defaultRates
}
// If the returned rate set is empty then used the default one.
if len(rates.m) == 0 {
return tl.defaultRates
}
return rates
}
type MaxRateError struct {
delay time.Duration
}
func (m *MaxRateError) Error() string {
return fmt.Sprintf("max rate reached: retry-in %v", m.delay)
}
type RateErrHandler struct {
}
func (e *RateErrHandler) ServeHTTP(w http.ResponseWriter, req *http.Request, err error) {
if rerr, ok := err.(*MaxRateError); ok {
w.Header().Set("X-Retry-In", rerr.delay.String())
w.WriteHeader(429)
w.Write([]byte(err.Error()))
return
}
utils.DefaultHandler.ServeHTTP(w, req, err)
}
type TokenLimiterOption func(l *TokenLimiter) error
// Logger sets the logger that will be used by this middleware.
func Logger(l utils.Logger) TokenLimiterOption {
return func(cl *TokenLimiter) error {
cl.log = l
return nil
}
}
// ErrorHandler sets error handler of the server
func ErrorHandler(h utils.ErrorHandler) TokenLimiterOption {
return func(cl *TokenLimiter) error {
cl.errHandler = h
return nil
}
}
func ExtractRates(e RateExtractor) TokenLimiterOption {
return func(cl *TokenLimiter) error {
cl.extractRates = e
return nil
}
}
func Clock(clock timetools.TimeProvider) TokenLimiterOption {
return func(cl *TokenLimiter) error {
cl.clock = clock
return nil
}
}
func Capacity(cap int) TokenLimiterOption {
return func(cl *TokenLimiter) error {
if cap <= 0 {
return fmt.Errorf("bad capacity: %v", cap)
}
cl.capacity = cap
return nil
}
}
var defaultErrHandler = &RateErrHandler{}
func setDefaults(tl *TokenLimiter) {
if tl.log == nil {
tl.log = utils.NullLogger
}
if tl.capacity <= 0 {
tl.capacity = DefaultCapacity
}
if tl.clock == nil {
tl.clock = &timetools.RealTime{}
}
if tl.errHandler == nil {
tl.errHandler = defaultErrHandler
}
}