remove cacheddns

CHANGELOG.md

@@ -16,7 +16,7 @@ The following emojis are used to highlight certain changes:
 
 ### Added
 
-* `gateway` now includes `NewRemoteBlocksBackend` which allows you to create a gateway backend that uses one or multiple other gateways as backend. These gateways must support RAW block requests, as well as IPNS Record requests. With this, we also introduced a `NewCacheBlockStore`, `NewCachedDNS`, `NewRemoteBlockstore` and `NewRemoteValueStore`. 
+* `gateway` now includes `NewRemoteBlocksBackend` which allows you to create a gateway backend that uses one or multiple other gateways as backend. These gateways must support RAW block requests, as well as IPNS Record requests. With this, we also introduced a `NewCacheBlockStore`, `NewRemoteBlockstore` and `NewRemoteValueStore`. 
 
 ### Changed
 

examples/go.mod

@@ -125,7 +125,6 @@ require (
 	github.com/quic-go/quic-go v0.40.1 // indirect
 	github.com/quic-go/webtransport-go v0.6.0 // indirect
 	github.com/raulk/go-watchdog v1.3.0 // indirect
-	github.com/rs/dnscache v0.0.0-20230804202142-fc85eb664529 // indirect
 	github.com/samber/lo v1.39.0 // indirect
 	github.com/spaolacci/murmur3 v1.1.0 // indirect
 	github.com/ucarion/urlpath v0.0.0-20200424170820-7ccc79b76bbb // indirect

examples/go.sum

@@ -403,8 +403,6 @@ github.com/raulk/go-watchdog v1.3.0/go.mod h1:fIvOnLbF0b0ZwkB9YU4mOW9Did//4vPZtD
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
-github.com/rs/dnscache v0.0.0-20230804202142-fc85eb664529 h1:18kd+8ZUlt/ARXhljq+14TwAoKa61q6dX8jtwOf6DH8=
-github.com/rs/dnscache v0.0.0-20230804202142-fc85eb664529/go.mod h1:qe5TWALJ8/a1Lqznoc5BDHpYX/8HU60Hm2AwRmqzxqA=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/samber/lo v1.39.0 h1:4gTz1wUhNYLhFSKl6O+8peW0v2F4BCY034GRpU9WnuA=

gateway/blockstore.go

@@ -155,14 +155,14 @@ type remoteBlockstore struct {
 // specification for more details.
 //
 // [Trustless Gateway]: https://specs.ipfs.tech/http-gateways/trustless-gateway/
-func NewRemoteBlockstore(gatewayURL []string, cdns *CachedDNS) (blockstore.Blockstore, error) {
+func NewRemoteBlockstore(gatewayURL []string) (blockstore.Blockstore, error) {
 	if len(gatewayURL) == 0 {
 		return nil, errors.New("missing gateway URLs to which to proxy")
 	}
 
 	return &remoteBlockstore{
 		gatewayURL: gatewayURL,
-		httpClient: newRemoteHTTPClient(cdns),
+		httpClient: newRemoteHTTPClient(),
 		rand:       rand.New(rand.NewSource(time.Now().Unix())),
 		// Enables block validation by default. Important since we are
 		// proxying block requests to untrusted gateways.

gateway/dns.go

@@ -1,16 +1,12 @@
 package gateway
 
 import (
-	"context"
 	"fmt"
-	"net"
 	"strings"
-	"time"
 
 	"github.com/libp2p/go-doh-resolver"
 	dns "github.com/miekg/dns"
 	madns "github.com/multiformats/go-multiaddr-dns"
-	"github.com/rs/dnscache"
 )
 
 var defaultResolvers = map[string]string{
@@ -94,58 +90,3 @@ func NewDNSResolver(resolvers map[string]string, dohOpts ...doh.Option) (*madns.
 
 	return madns.NewResolver(opts...)
 }
-
-// CachedDNS implements [http.Transport.DialContext], allowing to cache DNS
-// requests for a specified amount of time.
-type CachedDNS struct {
-	resolver  *dnscache.Resolver
-	refresher *time.Ticker
-}
-
-func NewCachedDNS(refreshInterval time.Duration) *CachedDNS {
-	cache := &CachedDNS{
-		resolver:  &dnscache.Resolver{},
-		refresher: time.NewTicker(refreshInterval),
-	}
-
-	// Configure DNS cache to not remove stale records to protect gateway from
-	// catastrophic failures like https://github.com/ipfs/bifrost-gateway/issues/34
-	options := dnscache.ResolverRefreshOptions{}
-	options.ClearUnused = false
-	options.PersistOnFailure = true
-
-	// Every refreshInterval we check for updates, but if there is
-	// none, or if domain disappears, we keep the last cached version
-	go func(cdns *CachedDNS) {
-		defer cdns.refresher.Stop()
-		for range cdns.refresher.C {
-			cdns.resolver.RefreshWithOptions(options)
-		}
-	}(cache)
-
-	return cache
-}
-func (cdns *CachedDNS) DialContext(ctx context.Context, network string, addr string) (conn net.Conn, err error) {
-	host, port, err := net.SplitHostPort(addr)
-	if err != nil {
-		return nil, err
-	}
-	ips, err := cdns.resolver.LookupHost(ctx, host)
-	if err != nil {
-		return nil, err
-	}
-	// Try all IPs returned by DNS
-	for _, ip := range ips {
-		var dialer net.Dialer
-		conn, err = dialer.DialContext(ctx, network, net.JoinHostPort(ip, port))
-		if err == nil {
-			break
-		}
-	}
-	return
-}
-
-func (cdns *CachedDNS) Close() error {
-	cdns.refresher.Stop()
-	return nil
-}

gateway/remote_blocks_backend.go

@@ -19,13 +19,13 @@ const getBlockTimeout = time.Second * 60
 // If you want to create a more custom [BlocksBackend] with only remote IPNS
 // Record resolution, or only remote block fetching, we recommend using
 // [NewBlocksBackend] directly.
-func NewRemoteBlocksBackend(gatewayURL []string, cdns *CachedDNS, opts ...BlocksBackendOption) (*BlocksBackend, error) {
-	blockStore, err := NewRemoteBlockstore(gatewayURL, cdns)
+func NewRemoteBlocksBackend(gatewayURL []string, opts ...BlocksBackendOption) (*BlocksBackend, error) {
+	blockStore, err := NewRemoteBlockstore(gatewayURL)
 	if err != nil {
 		return nil, err
 	}
 
-	valueStore, err := NewRemoteValueStore(gatewayURL, cdns)
+	valueStore, err := NewRemoteValueStore(gatewayURL)
 	if err != nil {
 		return nil, err
 	}
@@ -36,7 +36,7 @@ func NewRemoteBlocksBackend(gatewayURL []string, cdns *CachedDNS, opts ...Blocks
 
 // newRemoteHTTPClient creates a new [http.Client] that is optimized for retrieving
 // multiple blocks from a single gateway concurrently.
-func newRemoteHTTPClient(cdns *CachedDNS) *http.Client {
+func newRemoteHTTPClient() *http.Client {
 	transport := &http.Transport{
 		MaxIdleConns:        1000,
 		MaxConnsPerHost:     100,
@@ -45,10 +45,6 @@ func newRemoteHTTPClient(cdns *CachedDNS) *http.Client {
 		ForceAttemptHTTP2:   true,
 	}
 
-	if cdns != nil {
-		transport.DialContext = cdns.DialContext
-	}
-
 	return &http.Client{
 		Timeout:   getBlockTimeout,
 		Transport: otelhttp.NewTransport(transport),

gateway/value_store.go

@@ -25,14 +25,14 @@ type remoteValueStore struct {
 // specification for more details.
 //
 // [Trustless Gateway]: https://specs.ipfs.tech/http-gateways/trustless-gateway/
-func NewRemoteValueStore(gatewayURL []string, cdns *CachedDNS) (routing.ValueStore, error) {
+func NewRemoteValueStore(gatewayURL []string) (routing.ValueStore, error) {
 	if len(gatewayURL) == 0 {
 		return nil, errors.New("missing gateway URLs to which to proxy")
 	}
 
 	return &remoteValueStore{
 		gatewayURL: gatewayURL,
-		httpClient: newRemoteHTTPClient(cdns),
+		httpClient: newRemoteHTTPClient(),
 		rand:       rand.New(rand.NewSource(time.Now().Unix())),
 	}, nil
 }

go.mod

@@ -54,7 +54,6 @@ require (
 	github.com/pkg/errors v0.9.1
 	github.com/polydawn/refmt v0.89.0
 	github.com/prometheus/client_golang v1.18.0
-	github.com/rs/dnscache v0.0.0-20230804202142-fc85eb664529
 	github.com/samber/lo v1.39.0
 	github.com/spaolacci/murmur3 v1.1.0
 	github.com/stretchr/testify v1.8.4

go.sum

@@ -415,8 +415,6 @@ github.com/raulk/go-watchdog v1.3.0/go.mod h1:fIvOnLbF0b0ZwkB9YU4mOW9Did//4vPZtD
 github.com/rogpeppe/go-internal v1.3.0/go.mod h1:M8bDsm7K2OlrFYOpmOWEs/qY81heoFRclV5y23lUDJ4=
 github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/rogpeppe/go-internal v1.10.0/go.mod h1:UQnix2H7Ngw/k4C5ijL5+65zddjncjaFoBhdsK/akog=
-github.com/rs/dnscache v0.0.0-20230804202142-fc85eb664529 h1:18kd+8ZUlt/ARXhljq+14TwAoKa61q6dX8jtwOf6DH8=
-github.com/rs/dnscache v0.0.0-20230804202142-fc85eb664529/go.mod h1:qe5TWALJ8/a1Lqznoc5BDHpYX/8HU60Hm2AwRmqzxqA=
 github.com/russross/blackfriday v1.5.2/go.mod h1:JO/DiYxRf+HjHt06OyowR9PTA263kcR/rfWxYHBV53g=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/samber/lo v1.39.0 h1:4gTz1wUhNYLhFSKl6O+8peW0v2F4BCY034GRpU9WnuA=