Use hashicorp's LRU cache for DNS & certificates

DNS caching is also limited to 30 seconds now instead of 5 minutes

go.mod

@@ -10,6 +10,7 @@ require (
 	github.com/creasty/defaults v1.7.0
 	github.com/go-acme/lego/v4 v4.5.3
 	github.com/go-sql-driver/mysql v1.6.0
+	github.com/hashicorp/golang-lru/v2 v2.0.7
 	github.com/joho/godotenv v1.4.0
 	github.com/lib/pq v1.10.7
 	github.com/mattn/go-sqlite3 v1.14.16

go.sum

@@ -323,6 +323,8 @@ github.com/hashicorp/go-version v1.6.0/go.mod h1:fltr4n8CU8Ke44wwGCBoEymUuxUHl09
 github.com/hashicorp/go.net v0.0.1/go.mod h1:hjKkEWcCURg++eb33jQU7oqQcI9XDCnUzHA0oac0k90=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/golang-lru/v2 v2.0.7 h1:a+bsQ5rvGLjzHuww6tVxozPZFVghXaHOwFs4luLUK2k=
+github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/hashicorp/logutils v1.0.0/go.mod h1:QIAnNjmIWmVIIkWDTG1z5v++HQmx9WQRO+LraFDTW64=
 github.com/hashicorp/mdns v1.0.0/go.mod h1:tL+uN++7HEJ6SQLQ2/p+z2pH24WQKWjBPkE0mNTz8vQ=

server/certificates/certificates.go

@@ -10,6 +10,8 @@ import (
 	"strings"
 	"time"
 
+	lru "github.com/hashicorp/golang-lru/v2"
+
 	"github.com/go-acme/lego/v4/certcrypto"
 	"github.com/go-acme/lego/v4/certificate"
 	"github.com/go-acme/lego/v4/challenge/tlsalpn01"
@@ -26,12 +28,14 @@ import (
 
 var ErrUserRateLimitExceeded = errors.New("rate limit exceeded: 10 certificates per user per 24 hours")
 
+var keyCache *lru.Cache[string, tls.Certificate]
+
 // TLSConfig returns the configuration for generating, serving and cleaning up Let's Encrypt certificates.
 func TLSConfig(mainDomainSuffix string,
 	giteaClient *gitea.Client,
 	acmeClient *AcmeClient,
 	firstDefaultBranch string,
-	keyCache, challengeCache, dnsLookupCache, canonicalDomainCache cache.ICache,
+	challengeCache cache.ICache, canonicalDomainCache cache.ICache,
 	certDB database.CertDB,
 	noDNS01 bool,
 	rawDomain string,
@@ -86,7 +90,7 @@ func TLSConfig(mainDomainSuffix string,
 				}
 			} else {
 				var targetRepo, targetBranch string
-				targetOwner, targetRepo, targetBranch = dnsutils.GetTargetFromDNS(domain, mainDomainSuffix, firstDefaultBranch, dnsLookupCache)
+				targetOwner, targetRepo, targetBranch = dnsutils.GetTargetFromDNS(domain, mainDomainSuffix, firstDefaultBranch)
 				if targetOwner == "" {
 					// DNS not set up, return main certificate to redirect to the docs
 					domain = mainDomainSuffix
@@ -105,9 +109,17 @@ func TLSConfig(mainDomainSuffix string,
 				}
 			}
 
+			if keyCache == nil {
+				var err error
+				keyCache, err = lru.New[string, tls.Certificate](4096)
+				if err != nil {
+					panic(err) // This should only happen if 4096 < 0 at the time of writing, which should be reason enough to panic.
+				}
+			}
+
 			if tlsCertificate, ok := keyCache.Get(domain); ok {
 				// we can use an existing certificate object
-				return tlsCertificate.(*tls.Certificate), nil
+				return &tlsCertificate, nil
 			}
 
 			var tlsCertificate *tls.Certificate
@@ -132,9 +144,7 @@ func TLSConfig(mainDomainSuffix string,
 				}
 			}
 
-			if err := keyCache.Set(domain, tlsCertificate, 15*time.Minute); err != nil {
-				return nil, err
-			}
+			keyCache.Add(domain, *tlsCertificate)
 			return tlsCertificate, nil
 		},
 		NextProtos: []string{

server/dns/dns.go

@@ -5,22 +5,35 @@ import (
 	"strings"
 	"time"
 
-	"codeberg.org/codeberg/pages/server/cache"
+	lru "github.com/hashicorp/golang-lru/v2"
 )
 
-// lookupCacheTimeout specifies the timeout for the DNS lookup cache.
-var lookupCacheTimeout = 15 * time.Minute
+type lookupCacheEntry struct {
+	cachedName string
+	timestamp  time.Time
+}
+
+var lookupCacheValidity = 30 * time.Second
+
+var lookupCache *lru.Cache[string, lookupCacheEntry]
 
 var defaultPagesRepo = "pages"
 
 // GetTargetFromDNS searches for CNAME or TXT entries on the request domain ending with MainDomainSuffix.
 // If everything is fine, it returns the target data.
-func GetTargetFromDNS(domain, mainDomainSuffix, firstDefaultBranch string, dnsLookupCache cache.ICache) (targetOwner, targetRepo, targetBranch string) {
+func GetTargetFromDNS(domain, mainDomainSuffix, firstDefaultBranch string) (targetOwner, targetRepo, targetBranch string) {
 	// Get CNAME or TXT
 	var cname string
 	var err error
-	if cachedName, ok := dnsLookupCache.Get(domain); ok {
-		cname = cachedName.(string)
+
+	if lookupCache == nil {
+		lookupCache, err = lru.New[string, lookupCacheEntry](4096)
+		if err != nil {
+			panic(err) // This should only happen if 4096 < 0 at the time of writing, which should be reason enough to panic.
+		}
+	}
+	if entry, ok := lookupCache.Get(domain); ok && time.Now().Before(entry.timestamp.Add(lookupCacheValidity)) {
+		cname = entry.cachedName
 	} else {
 		cname, err = net.LookupCNAME(domain)
 		cname = strings.TrimSuffix(cname, ".")
@@ -38,7 +51,10 @@ func GetTargetFromDNS(domain, mainDomainSuffix, firstDefaultBranch string, dnsLo
 				}
 			}
 		}
-		_ = dnsLookupCache.Set(domain, cname, lookupCacheTimeout)
+		_ = lookupCache.Add(domain, lookupCacheEntry{
+			cname,
+			time.Now(),
+		})
 	}
 	if cname == "" {
 		return

server/handler/handler.go

@@ -23,7 +23,7 @@ const (
 func Handler(
 	cfg config.ServerConfig,
 	giteaClient *gitea.Client,
-	dnsLookupCache, canonicalDomainCache, redirectsCache cache.ICache,
+	canonicalDomainCache, redirectsCache cache.ICache,
 ) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
 		log.Debug().Msg("\n----------------------------------------------------------")
@@ -108,7 +108,7 @@ func Handler(
 				trimmedHost,
 				pathElements,
 				cfg.PagesBranches[0],
-				dnsLookupCache, canonicalDomainCache, redirectsCache)
+				canonicalDomainCache, redirectsCache)
 		}
 	}
 }

server/handler/handler_custom_domain.go

@@ -19,10 +19,10 @@ func handleCustomDomain(log zerolog.Logger, ctx *context.Context, giteaClient *g
 	trimmedHost string,
 	pathElements []string,
 	firstDefaultBranch string,
-	dnsLookupCache, canonicalDomainCache, redirectsCache cache.ICache,
+	canonicalDomainCache, redirectsCache cache.ICache,
 ) {
 	// Serve pages from custom domains
-	targetOwner, targetRepo, targetBranch := dns.GetTargetFromDNS(trimmedHost, mainDomainSuffix, firstDefaultBranch, dnsLookupCache)
+	targetOwner, targetRepo, targetBranch := dns.GetTargetFromDNS(trimmedHost, mainDomainSuffix, firstDefaultBranch)
 	if targetOwner == "" {
 		html.ReturnErrorPage(ctx,
 			"could not obtain repo owner from custom domain",
@@ -53,7 +53,7 @@ func handleCustomDomain(log zerolog.Logger, ctx *context.Context, giteaClient *g
 			return
 		} else if canonicalDomain != trimmedHost {
 			// only redirect if the target is also a codeberg page!
-			targetOwner, _, _ = dns.GetTargetFromDNS(strings.SplitN(canonicalDomain, "/", 2)[0], mainDomainSuffix, firstDefaultBranch, dnsLookupCache)
+			targetOwner, _, _ = dns.GetTargetFromDNS(strings.SplitN(canonicalDomain, "/", 2)[0], mainDomainSuffix, firstDefaultBranch)
 			if targetOwner != "" {
 				ctx.Redirect("https://"+canonicalDomain+"/"+targetOpt.TargetPath, http.StatusTemporaryRedirect)
 				return

server/handler/handler_test.go

@@ -29,7 +29,7 @@ func TestHandlerPerformance(t *testing.T) {
 		AllowedCorsDomains: []string{"raw.codeberg.org", "fonts.codeberg.org", "design.codeberg.org"},
 		PagesBranches:      []string{"pages"},
 	}
-	testHandler := Handler(serverCfg, giteaClient, cache.NewInMemoryCache(), cache.NewInMemoryCache(), cache.NewInMemoryCache())
+	testHandler := Handler(serverCfg, giteaClient, cache.NewInMemoryCache(), cache.NewInMemoryCache())
 
 	testCase := func(uri string, status int) {
 		t.Run(uri, func(t *testing.T) {

server/startup.go

@@ -66,12 +66,9 @@ func Serve(ctx *cli.Context) error {
 	}
 	defer closeFn()
 
-	keyCache := cache.NewInMemoryCache()
 	challengeCache := cache.NewInMemoryCache()
 	// canonicalDomainCache stores canonical domains
 	canonicalDomainCache := cache.NewInMemoryCache()
-	// dnsLookupCache stores DNS lookups for custom domains
-	dnsLookupCache := cache.NewInMemoryCache()
 	// redirectsCache stores redirects in _redirects files
 	redirectsCache := cache.NewInMemoryCache()
 	// clientResponseCache stores responses from the Gitea server
@@ -104,7 +101,7 @@ func Serve(ctx *cli.Context) error {
 		giteaClient,
 		acmeClient,
 		cfg.Server.PagesBranches[0],
-		keyCache, challengeCache, dnsLookupCache, canonicalDomainCache,
+		challengeCache, canonicalDomainCache,
 		certDB,
 		cfg.ACME.NoDNS01,
 		cfg.Server.RawDomain,
@@ -134,7 +131,7 @@ func Serve(ctx *cli.Context) error {
 	}
 
 	// Create ssl handler based on settings
-	sslHandler := handler.Handler(cfg.Server, giteaClient, dnsLookupCache, canonicalDomainCache, redirectsCache)
+	sslHandler := handler.Handler(cfg.Server, giteaClient, canonicalDomainCache, redirectsCache)
 
 	// Start the ssl listener
 	log.Info().Msgf("Start SSL server using TCP listener on %s", listener.Addr())