ratelimit

Documentation

Overview

Package ratelimit Tokenbucket based request rate limiter

Index

• Constants
• func FromCli(c *cli.Context) (plugin.Middleware, error)
• func FromOther(o RateLimit) (plugin.Middleware, error)
• func GetSpec() *plugin.MiddlewareSpec
• type MaxRateError
  • func (m *MaxRateError) Error() string
• type RateErrHandler
  • func (e *RateErrHandler) ServeHTTP(w http.ResponseWriter, req *http.Request, err error)
• type RateExtractor
• type RateExtractorFunc
  • func (e RateExtractorFunc) Extract(r *http.Request) (*RateSet, error)
• type RateLimit
  • func (r *RateLimit) NewHandler(next http.Handler) (http.Handler, error)
  • func (rl *RateLimit) String() string
• type RateSet
  • func NewRateSet() *RateSet
  • func (rs *RateSet) Add(period time.Duration, average int64, burst int64) error
  • func (rs *RateSet) String() string
• type TokenBucketSet
  • func NewTokenBucketSet(rates *RateSet, clock timetools.TimeProvider) *TokenBucketSet
  • func (tbs *TokenBucketSet) Consume(tokens int64) (time.Duration, error)
  • func (tbs *TokenBucketSet) GetMaxPeriod() time.Duration
  • func (tbs *TokenBucketSet) Update(rates *RateSet)
• type TokenLimiter
  • func New(next http.Handler, extract utils.SourceExtractor, defaultRates *RateSet, ...) (*TokenLimiter, error)
  • func (tl *TokenLimiter) ServeHTTP(w http.ResponseWriter, req *http.Request)
  • func (tl *TokenLimiter) Wrap(next http.Handler)
• type TokenLimiterOption
  • func Capacity(cap int) TokenLimiterOption
  • func Clock(clock timetools.TimeProvider) TokenLimiterOption
  • func ErrorHandler(h utils.ErrorHandler) TokenLimiterOption
  • func ExtractRates(e RateExtractor) TokenLimiterOption
  • func Logger(l *log.Logger) TokenLimiterOption

Constants

const DefaultCapacity = 65536

DefaultCapacity default capacity

const UndefinedDelay = -1

UndefinedDelay default delay

Functions

func FromCli

func FromCli(c *cli.Context) (plugin.Middleware, error)

FromCli constructs a middleware instance from the command line parameters.

func FromOther

func FromOther(o RateLimit) (plugin.Middleware, error)

func GetSpec

func GetSpec() *plugin.MiddlewareSpec

Spec is an entry point of a plugin and will be called to register this middleware plugin withing vulcand

Types

type MaxRateError

type MaxRateError struct {
	// contains filtered or unexported fields
}

MaxRateError max rate error

func (*MaxRateError) Error

func (m *MaxRateError) Error() string

type RateErrHandler

type RateErrHandler struct{}

RateErrHandler error handler

func (*RateErrHandler) ServeHTTP

func (e *RateErrHandler) ServeHTTP(w http.ResponseWriter, req *http.Request, err error)

type RateExtractor

type RateExtractor interface {
	Extract(r *http.Request) (*RateSet, error)
}

RateExtractor rate extractor

type RateExtractorFunc

type RateExtractorFunc func(r *http.Request) (*RateSet, error)

RateExtractorFunc rate extractor function type

func (RateExtractorFunc) Extract

func (e RateExtractorFunc) Extract(r *http.Request) (*RateSet, error)

Extract extract from request

type RateLimit

type RateLimit struct {
	// Period in seconds, e.g. 3600 to set up hourly rates
	PeriodSeconds int64
	// Allowed average requests
	Requests int64
	// Burst count, allowes some extra variance for requests exceeding the average rate
	Burst int64
	// Variable defines how the limiting should be done. e.g. 'client.ip' or 'request.header.X-My-Header'
	Variable string
	// RateVar defines the source of rates configuration that should be used to
	// process a particular request. E.g. 'request.header.X-Rates'
	RateVar string
	// contains filtered or unexported fields
}

Rate controls how many requests per period of time is allowed for a location. Existing implementation is based on the token bucket algorightm http://en.wikipedia.org/wiki/Token_bucket

func (*RateLimit) NewHandler

func (r *RateLimit) NewHandler(next http.Handler) (http.Handler, error)

Returns vulcan library compatible middleware

func (*RateLimit) String

func (rl *RateLimit) String() string

type RateSet

type RateSet struct {
	// contains filtered or unexported fields
}

RateSet maintains a set of rates. It can contain only one rate per period at a time.

func NewRateSet

func NewRateSet() *RateSet

NewRateSet crates an empty `RateSet` instance.

func (*RateSet) Add

func (rs *RateSet) Add(period time.Duration, average int64, burst int64) error

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 (*RateSet) String

func (rs *RateSet) String() string

type TokenBucketSet

type TokenBucketSet struct {
	// contains filtered or unexported fields
}

TokenBucketSet represents a set of TokenBucket covering different time periods.

func NewTokenBucketSet

func NewTokenBucketSet(rates *RateSet, clock timetools.TimeProvider) *TokenBucketSet

NewTokenBucketSet creates a `TokenBucketSet` from the specified `rates`.

func (*TokenBucketSet) Consume

func (tbs *TokenBucketSet) Consume(tokens int64) (time.Duration, error)

Consume consume tokens

func (*TokenBucketSet) GetMaxPeriod

func (tbs *TokenBucketSet) GetMaxPeriod() time.Duration

GetMaxPeriod returns the max period

func (*TokenBucketSet) Update

func (tbs *TokenBucketSet) Update(rates *RateSet)

Update brings the buckets in the set in accordance with the provided `rates`.

type TokenLimiter

type TokenLimiter struct {
	// contains filtered or unexported fields
}

TokenLimiter implements rate limiting middleware.

func New

func New(next http.Handler, extract utils.SourceExtractor, defaultRates *RateSet, opts ...TokenLimiterOption) (*TokenLimiter, error)

New constructs a `TokenLimiter` middleware instance.

func (*TokenLimiter) ServeHTTP

func (tl *TokenLimiter) ServeHTTP(w http.ResponseWriter, req *http.Request)

func (*TokenLimiter) Wrap

func (tl *TokenLimiter) Wrap(next http.Handler)

Wrap sets the next handler to be called by token limiter handler.

type TokenLimiterOption

type TokenLimiterOption func(l *TokenLimiter) error

TokenLimiterOption token limiter option type

func Capacity

func Capacity(cap int) TokenLimiterOption

Capacity sets the capacity

func Clock

func Clock(clock timetools.TimeProvider) TokenLimiterOption

Clock sets the clock

func ErrorHandler

func ErrorHandler(h utils.ErrorHandler) TokenLimiterOption

ErrorHandler sets error handler of the server

func ExtractRates

func ExtractRates(e RateExtractor) TokenLimiterOption

ExtractRates sets the rate extractor

func Logger

func Logger(l *log.Logger) TokenLimiterOption

Logger defines the logger the token limiter will use.

It defaults to logrus.StandardLogger(), the global logger used by logrus.