fix(ogtags): cache SNI clients and simplify request handling

internal/ogtags/fetch.go

@@ -2,7 +2,6 @@ package ogtags
 
 import (
 	"context"
-	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
@@ -28,42 +27,26 @@ func (c *OGTagCache) fetchHTMLDocumentWithCache(ctx context.Context, urlStr stri
 	}
 
 	// Set the Host header to the original host
+	var hostForRequest string
 	switch {
 	case c.targetHost != "":
-		req.Host = c.targetHost
+		hostForRequest = c.targetHost
 	case originalHost != "":
-		req.Host = originalHost
+		hostForRequest = originalHost
+	}
+	if hostForRequest != "" {
+		req.Host = hostForRequest
 	}
 
 	// Add proxy headers
 	req.Header.Set("X-Forwarded-Proto", "https")
 	req.Header.Set("User-Agent", "Anubis-OGTag-Fetcher/1.0") // For tracking purposes
 
-	client := c.client
-
-	if c.targetSNIAuto {
-		serverName := originalHost
-		if c.targetHost != "" {
-			serverName = c.targetHost
-		}
-
-		if serverName != "" {
-			transport := c.transport.Clone()
-			if transport.TLSClientConfig == nil {
-				transport.TLSClientConfig = &tls.Config{}
-			}
-			transport.TLSClientConfig.ServerName = serverName
-			if c.insecureSkipVerify {
-				transport.TLSClientConfig.InsecureSkipVerify = true
-			}
-
-			client = &http.Client{
-				Timeout:   httpTimeout,
-				Transport: transport,
-			}
-			defer transport.CloseIdleConnections()
-		}
+	serverName := hostForRequest
+	if serverName == "" {
+		serverName = req.URL.Hostname()
 	}
+	client := c.clientForSNI(serverName)
 
 	// Send the request
 	resp, err := client.Do(req)

internal/ogtags/ogtags.go

@@ -8,6 +8,7 @@ import (
 	"net/http"
 	"net/url"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/TecharoHQ/anubis/lib/policy/config"
@@ -40,6 +41,8 @@ type OGTagCache struct {
 	targetSNI           string
 	targetSNIAuto       bool
 	insecureSkipVerify  bool
+	sniClients          map[string]*http.Client
+	transportMu         sync.RWMutex
 }
 
 type TargetOptions struct {
@@ -124,6 +127,7 @@ func NewOGTagCache(target string, conf config.OpenGraph, backend store.Interface
 		targetSNI:           targetOpts.SNI,
 		targetSNIAuto:       targetSNIAuto,
 		insecureSkipVerify:  targetOpts.InsecureSkipVerify,
+		sniClients:          make(map[string]*http.Client),
 	}
 }
 

internal/ogtags/sni.go

@@ -0,0 +1,42 @@
+package ogtags
+
+import (
+	"crypto/tls"
+	"net/http"
+)
+
+// clientForSNI returns a cached client for the given server name, creating one if needed.
+func (c *OGTagCache) clientForSNI(serverName string) *http.Client {
+	if !c.targetSNIAuto || serverName == "" {
+		return c.client
+	}
+
+	c.transportMu.RLock()
+	cli, ok := c.sniClients[serverName]
+	c.transportMu.RUnlock()
+	if ok {
+		return cli
+	}
+
+	c.transportMu.Lock()
+	defer c.transportMu.Unlock()
+	if cli, ok := c.sniClients[serverName]; ok {
+		return cli
+	}
+
+	tr := c.transport.Clone()
+	if tr.TLSClientConfig == nil {
+		tr.TLSClientConfig = &tls.Config{}
+	}
+	tr.TLSClientConfig.ServerName = serverName
+	if c.insecureSkipVerify {
+		tr.TLSClientConfig.InsecureSkipVerify = true
+	}
+
+	cli = &http.Client{
+		Timeout:   httpTimeout,
+		Transport: tr,
+	}
+	c.sniClients[serverName] = cli
+	return cli
+}