archivingcache

Documentation

Overview

Package archivecache is a CoreDNS plugin that caches lookups and writes. If more than one request for the same resource is in flight, then they are queued to avoid redundant forwarding lookups

Index

• Constants
• Variables
• type ArchivingCache
  • func NewArchivingCache(cache *Cache, lw *LogWriterClient, cw *ContentWriterClient) *ArchivingCache
  • func (a *ArchivingCache) Name() string
  • func (a *ArchivingCache) OnShutdown() (err error)
  • func (a *ArchivingCache) OnStartup() error
  • func (a *ArchivingCache) Ready() bool
  • func (a *ArchivingCache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)
• type Cache
  • func NewCache(lifeWindow time.Duration, maxSizeMb int) (*Cache, error)
  • func (c *Cache) Get(key string) (*CacheEntry, error)
  • func (c *Cache) Len() int
  • func (c *Cache) Reset() error
  • func (c *Cache) Set(key string, entry *CacheEntry) error
• type CacheEntry
  • func (ce *CacheEntry) AddCollectionId(collectionId string) []string
  • func (ce *CacheEntry) HasCollectionId(collectionId string) bool
  • func (ce *CacheEntry) String() string
• type ContentWriterClient
  • func NewContentWriterClient(opts ...serviceconnections.ConnectionOption) *ContentWriterClient
  • func (c *ContentWriterClient) Connect() error
  • func (c *ContentWriterClient) WriteRecord(payload []byte, fetchStart time.Time, requestedHost string, ipAddress string, ...) (*contentwriterV1.WriteReply, error)
• type LogWriterClient
  • func NewLogWriterClient(opts ...serviceconnections.ConnectionOption) *LogWriterClient
  • func (l *LogWriterClient) Connect() error
  • func (l *LogWriterClient) WriteCrawlLog(record *contentwriterV1.WriteResponseMeta_RecordMeta, size int, ...) error
• type Recorder
  • func NewRecorder(w dns.ResponseWriter) *Recorder
  • func (w *Recorder) WriteMsg(res *dns.Msg) error

Constants

const (
	// Success is the class for caching positive caching.
	Success = "success"
	// Denial is the class defined for negative caching.
	Denial = "denial"
)

Variables

var (
	CacheSize = promauto.NewGaugeVec(prometheus.GaugeOpts{
		Namespace: plugin.Namespace,
		Subsystem: "cache",
		Name:      "size",
		Help:      "The number of elements in the cache.",
	}, []string{"server", "type"})

	CacheHits = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: plugin.Namespace,
		Subsystem: "cache",
		Name:      "hits_total",
		Help:      "The count of cache hits.",
	}, []string{"server", "type"})

	CacheMisses = promauto.NewCounterVec(prometheus.CounterOpts{
		Namespace: plugin.Namespace,
		Subsystem: "cache",
		Name:      "misses_total",
		Help:      "The count of cache misses.",
	}, []string{"server"})
)

Types

type ArchivingCache

type ArchivingCache struct {
	Next plugin.Handler

	singleflight.Group
	// contains filtered or unexported fields
}

ArchivingCache is a CoreDNS plugin.

func NewArchivingCache

func NewArchivingCache(cache *Cache, lw *LogWriterClient, cw *ContentWriterClient) *ArchivingCache

NewArchivingCache returns a new instance of ArchivingCache

func (*ArchivingCache) Name

func (a *ArchivingCache) Name() string

Name implements the Handler interface.

func (*ArchivingCache) OnShutdown

func (a *ArchivingCache) OnShutdown() (err error)

OnShutdown closes connections to content writer and log writer.

func (*ArchivingCache) OnStartup

func (a *ArchivingCache) OnStartup() error

OnStartup connects to content writer and log writer.

func (*ArchivingCache) Ready

func (a *ArchivingCache) Ready() bool

func (*ArchivingCache) ServeDNS

func (a *ArchivingCache) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error)

ServeDNS implements the plugin.Handler interface.

type Cache

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

Cache is a wrapper around *bigcache.BigCache which takes care of marshalling and unmarshalling of dns.Msg.

func NewCache

func NewCache(lifeWindow time.Duration, maxSizeMb int) (*Cache, error)

NewCache creates a new Cache

func (*Cache) Get

func (c *Cache) Get(key string) (*CacheEntry, error)

Get reads a DNS response from the cache. It returns an EntryNotFoundError when no entry exists for the given key.

func (*Cache) Len

func (c *Cache) Len() int

func (*Cache) Reset

func (c *Cache) Reset() error

func (*Cache) Set

func (c *Cache) Set(key string, entry *CacheEntry) error

Set writes a DNS response to the cache

type CacheEntry

type CacheEntry struct {
	ProxyAddr     string
	CollectionIds []string
	Msg           *dns.Msg
}

func (*CacheEntry) AddCollectionId

func (ce *CacheEntry) AddCollectionId(collectionId string) []string

func (*CacheEntry) HasCollectionId

func (ce *CacheEntry) HasCollectionId(collectionId string) bool

func (*CacheEntry) String

func (ce *CacheEntry) String() string

type ContentWriterClient

type ContentWriterClient struct {
	*serviceconnections.Connection
	contentwriterV1.ContentWriterClient
}

ContentWriterClient holds the connections for ContentWriterClient and Veidemann database

func NewContentWriterClient

func NewContentWriterClient(opts ...serviceconnections.ConnectionOption) *ContentWriterClient

NewContentWriterClient creates a new ContentWriterClient object

func (*ContentWriterClient) Connect

func (c *ContentWriterClient) Connect() error

Connect establishes connections

func (*ContentWriterClient) WriteRecord

func (c *ContentWriterClient) WriteRecord(payload []byte, fetchStart time.Time, requestedHost string, ipAddress string, executionId string, collectionId string) (*contentwriterV1.WriteReply, error)

WriteRecord writes a WARC record.

type LogWriterClient

type LogWriterClient struct {
	*serviceconnections.Connection
	*logservice.LogWriter
}

func NewLogWriterClient

func NewLogWriterClient(opts ...serviceconnections.ConnectionOption) *LogWriterClient

func (*LogWriterClient) Connect

func (l *LogWriterClient) Connect() error

func (*LogWriterClient) WriteCrawlLog

func (l *LogWriterClient) WriteCrawlLog(record *contentwriterV1.WriteResponseMeta_RecordMeta, size int, requestedHost string, fetchStart time.Time, fetchDurationMs int64, ipAddress string, executionId string) error

WriteCrawlLog stores a crawl log of a dns request/response.

type Recorder

type Recorder struct {
	dns.ResponseWriter
	Rcode int
	Msg   *dns.Msg
}

func NewRecorder

func NewRecorder(w dns.ResponseWriter) *Recorder

NewRecorder makes and returns a new Recorder.

func (*Recorder) WriteMsg

func (w *Recorder) WriteMsg(res *dns.Msg) error

WriteMsg records the message and the response code, but doesn't write anything to the client.