dnscache

Documentation

Index

• type DialContextFunc
• type DnsCacheItem
• type DnsCacheManager
  • func NewDnsCacheManager(multipleIPsHandleStrategy config.IPsHandleStrategy) *DnsCacheManager
  • func (m *DnsCacheManager) CacheStorage() IDnsCacheStorage
  • func (m *DnsCacheManager) DisposeCache()
  • func (m *DnsCacheManager) InitDNSCaching(ttl, checkInterval time.Duration)
  • func (m *DnsCacheManager) IsCacheEnabled() bool
  • func (m *DnsCacheManager) SetCacheStorage(cache IDnsCacheStorage)
  • func (m *DnsCacheManager) WrapDialer(dialer *net.Dialer) DialContextFunc
• type DnsCacheStorage
  • func NewDnsCacheStorage(expiration, checkInterval time.Duration) *DnsCacheStorage
  • func (dc *DnsCacheStorage) Clear()
  • func (dc *DnsCacheStorage) Delete(key string)
  • func (dc *DnsCacheStorage) FetchItem(hostName string) ([]string, error)
  • func (dc *DnsCacheStorage) Get(key string) (DnsCacheItem, bool)
  • func (dc *DnsCacheStorage) Items(includeExpired bool) map[string]DnsCacheItem
  • func (dc *DnsCacheStorage) Set(key string, addrs []string)
• type IDnsCacheManager
• type IDnsCacheStorage
• type MockStorage
  • func (ms *MockStorage) Clear()
  • func (ms *MockStorage) Delete(key string)
  • func (ms *MockStorage) FetchItem(key string) ([]string, error)
  • func (ms *MockStorage) Get(key string) (DnsCacheItem, bool)
  • func (ms *MockStorage) Set(key string, addrs []string)

Types

type DialContextFunc

type DialContextFunc func(ctx context.Context, network, address string) (net.Conn, error)

type DnsCacheItem

type DnsCacheItem struct {
	Addrs []string
}

DnsCacheItem represents single record in cache

type DnsCacheManager

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

DnsCacheManager is responsible for in-memory dns query records cache. It allows to init dns caching and to hook into net/http dns resolution chain in order to cache query response ip records.

func NewDnsCacheManager

func NewDnsCacheManager(multipleIPsHandleStrategy config.IPsHandleStrategy) *DnsCacheManager

NewDnsCacheManager returns new empty/non-initialized DnsCacheManager

func (*DnsCacheManager) CacheStorage

func (m *DnsCacheManager) CacheStorage() IDnsCacheStorage

func (*DnsCacheManager) DisposeCache

func (m *DnsCacheManager) DisposeCache()

DisposeCache clear all entries from cache and disposes/disables caching of dns queries

func (*DnsCacheManager) InitDNSCaching

func (m *DnsCacheManager) InitDNSCaching(ttl, checkInterval time.Duration)

InitDNSCaching initializes manager's cache storage if it wasn't initialized before with provided ttl, checkinterval values Initialized cache storage enables caching of previously hoooked net.Dialer DialContext calls

Otherwise leave storage as is.

func (*DnsCacheManager) IsCacheEnabled

func (m *DnsCacheManager) IsCacheEnabled() bool

func (*DnsCacheManager) SetCacheStorage

func (m *DnsCacheManager) SetCacheStorage(cache IDnsCacheStorage)

func (*DnsCacheManager) WrapDialer

func (m *DnsCacheManager) WrapDialer(dialer *net.Dialer) DialContextFunc

WrapDialer returns wrapped version of net.Dialer#DialContext func with hooked up caching of dns queries.

Actual dns server call occures in net.Resolver#LookupIPAddr method, linked to net.Dialer instance by net.Dialer#Resolver field

type DnsCacheStorage

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

DnsCacheStorage is an in-memory cache of auto-purged dns query ip responses

func NewDnsCacheStorage

func NewDnsCacheStorage(expiration, checkInterval time.Duration) *DnsCacheStorage

func (*DnsCacheStorage) Clear

func (dc *DnsCacheStorage) Clear()

Clear deletes all records from cache

func (*DnsCacheStorage) Delete

func (dc *DnsCacheStorage) Delete(key string)

func (*DnsCacheStorage) FetchItem

func (dc *DnsCacheStorage) FetchItem(hostName string) ([]string, error)

FetchItem returns list of ips from cache or resolves them and add to cache

func (*DnsCacheStorage) Get

func (dc *DnsCacheStorage) Get(key string) (DnsCacheItem, bool)

Get returns non expired item from cache

func (*DnsCacheStorage) Items

func (dc *DnsCacheStorage) Items(includeExpired bool) map[string]DnsCacheItem

Items returns map of non expired dns cache items

func (*DnsCacheStorage) Set

func (dc *DnsCacheStorage) Set(key string, addrs []string)

type IDnsCacheManager

type IDnsCacheManager interface {
	InitDNSCaching(ttl, checkInterval time.Duration)
	WrapDialer(dialer *net.Dialer) DialContextFunc
	SetCacheStorage(cache IDnsCacheStorage)
	CacheStorage() IDnsCacheStorage
	IsCacheEnabled() bool
	DisposeCache()
}

IDnsCacheManager is an interface for abstracting interaction with dns cache. Implemented by DnsCacheManager

type IDnsCacheStorage

type IDnsCacheStorage interface {
	FetchItem(key string) ([]string, error)
	Get(key string) (DnsCacheItem, bool)
	Set(key string, addrs []string)
	Delete(key string)
	Clear()
}

IDnsCacheStorage is an interface for working with cached storage of dns record. Wrapped by IDnsCacheManager/DnsCacheManager. Implemented by DnsCacheStorage

type MockStorage

type MockStorage struct {
	MockFetchItem func(key string) ([]string, error)
	MockGet       func(key string) (DnsCacheItem, bool)
	MockSet       func(key string, addrs []string)
	MockDelete    func(key string)
	MockClear     func()
}

func (*MockStorage) Clear

func (ms *MockStorage) Clear()

func (*MockStorage) Delete

func (ms *MockStorage) Delete(key string)

func (*MockStorage) FetchItem

func (ms *MockStorage) FetchItem(key string) ([]string, error)

func (*MockStorage) Get

func (ms *MockStorage) Get(key string) (DnsCacheItem, bool)

func (*MockStorage) Set

func (ms *MockStorage) Set(key string, addrs []string)