krakendrate

README

KrakenD rate limit

A rate limit middleware for KrakenD

Documentation

1. Official: https://www.krakend.io/docs/throttling/

2. Autogenerated: https://godoc.org/github.com/breathbath/krakend-ratelimit/v3

Documentation

Overview

krakendrate contains a collection of curated rate limit adaptors for the KrakenD framework

Index

• Variables
• func PseudoFNV64a(s string) uint64
• type Backend
• type Clock
• type Hasher
• type Limiter
• type LimiterStore
  • func NewLimiterStore(maxRate float64, capacity int, backend Backend, logger logging.Logger) LimiterStore
  • func NewMemoryStore(maxRate float64, capacity int, logger logging.Logger) LimiterStore
• type MemoryBackend
  • func NewMemoryBackend(ctx context.Context, ttl time.Duration) *MemoryBackend
  • func (m *MemoryBackend) Load(key string, f func() interface{}) interface{}
  • func (m *MemoryBackend) Store(key string, v interface{}) error
• type ShardedMemoryBackend
  • func DefaultShardedMemoryBackend(ctx context.Context) *ShardedMemoryBackend
  • func NewShardedMemoryBackend(ctx context.Context, shards uint64, ttl time.Duration, h Hasher) *ShardedMemoryBackend
  • func (b *ShardedMemoryBackend) Load(key string, f func() interface{}) interface{}
  • func (b *ShardedMemoryBackend) Store(key string, v interface{}) error
• type TokenBucket
  • func NewTokenBucket(rate float64, capacity uint64) *TokenBucket
  • func NewTokenBucketWithClock(rate float64, capacity uint64, c Clock) *TokenBucket
  • func NewTokenBucketWithInitialStock(r float64, capacity, i uint64, c Clock) *TokenBucket
  • func (t *TokenBucket) Allow() bool

Variables

var (
	// ErrLimited is the error returned when the rate limit has been exceded
	ErrLimited = errors.New("rate limit exceded")

	// DataTTL is the default eviction time
	DataTTL = 10 * time.Minute

	// DefaultShards are the number of shards to create by default
	DefaultShards uint64 = 2048
)

Functions

func PseudoFNV64a

func PseudoFNV64a(s string) uint64

Types

type Backend

type Backend interface {
	Load(string, func() interface{}) interface{}
	Store(string, interface{}) error
}

Backend is the interface of the persistence layer

type Clock

type Clock interface {
	Now() time.Time
	Since(time.Time) time.Duration
}

Clock defines the interface for clock sources

type Hasher

type Hasher func(string) uint64

Hasher gets a hash for the received string

type Limiter

type Limiter interface {
	Allow() bool
}

Limiter defines a simple interface for a rate limiter

type LimiterStore

type LimiterStore func(key string, maxRate float64, capacity int) Limiter

LimiterStore defines the interface for a limiter lookup function

func NewLimiterStore

func NewLimiterStore(maxRate float64, capacity int, backend Backend, logger logging.Logger) LimiterStore

NewLimiterStore returns a LimiterStore using the received backend for persistence

func NewMemoryStore

func NewMemoryStore(maxRate float64, capacity int, logger logging.Logger) LimiterStore

NewMemoryStore returns a LimiterStore using the memory backend

type MemoryBackend

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

MemoryBackend implements the backend interface by wrapping a sync.Map

func NewMemoryBackend

func NewMemoryBackend(ctx context.Context, ttl time.Duration) *MemoryBackend

func (*MemoryBackend) Load

func (m *MemoryBackend) Load(key string, f func() interface{}) interface{}

Load implements the Backend interface

func (*MemoryBackend) Store

func (m *MemoryBackend) Store(key string, v interface{}) error

Store implements the Backend interface

type ShardedMemoryBackend

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

ShardedMemoryBackend is a memory backend shardering the data in order to avoid mutex contention

func DefaultShardedMemoryBackend

func DefaultShardedMemoryBackend(ctx context.Context) *ShardedMemoryBackend

DefaultShardedMemoryBackend is a 2018 sharded ShardedMemoryBackend

func NewShardedMemoryBackend

func NewShardedMemoryBackend(ctx context.Context, shards uint64, ttl time.Duration, h Hasher) *ShardedMemoryBackend

NewShardedMemoryBackend returns a ShardedMemoryBackend with 'shards' shards

func (*ShardedMemoryBackend) Load

func (b *ShardedMemoryBackend) Load(key string, f func() interface{}) interface{}

Load implements the Backend interface

func (*ShardedMemoryBackend) Store

func (b *ShardedMemoryBackend) Store(key string, v interface{}) error

Store implements the Backend interface

type TokenBucket

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

TokenBucket is an implementation of the token bucket pattern

func NewTokenBucket

func NewTokenBucket(rate float64, capacity uint64) *TokenBucket

NewTokenBucket returns a token bucket with the given rate and capacity, using the default clock and an initial stock of cap

func NewTokenBucketWithClock

func NewTokenBucketWithClock(rate float64, capacity uint64, c Clock) *TokenBucket

NewTokenBucketWithClock returns a token bucket with the given rate, capacity, and clock and an initial stock of capacity

func NewTokenBucketWithInitialStock

func NewTokenBucketWithInitialStock(r float64, capacity, i uint64, c Clock) *TokenBucket

NewTokenBucketWithInitialStock returns a token bucket with the given rate, capacity, clock and initial stock

func (*TokenBucket) Allow

func (t *TokenBucket) Allow() bool

Allow flags if the current request can be processed or not. It updates the internal state if the request can be processed