Make product API versions independently installable

backend/product/sessions/browser/browser.go

@@ -1,9 +1,9 @@
 package browser
 
 import (
+	"context"
 	"net/http"
 	"net/url"
-	"os"
 	"path"
 	"strings"
 	"time"
@@ -86,8 +86,10 @@ func ValidateCSRF(r *http.Request, allowedOrigins []string) error {
 
 func cookiePath(r *http.Request) string {
 	const accountsSegment = "/accounts"
-	if apiEndpoint := strings.TrimSpace(os.Getenv("API_ENDPOINT")); apiEndpoint != "" {
-		return path.Join("/", apiEndpoint, accountsSegment)
+	if r != nil {
+		if mount, ok := r.Context().Value(scopeKey{}).(string); ok {
+			return path.Join(mount, accountsSegment)
+		}
 	}
 	if r != nil && r.URL != nil {
 		if index := strings.Index(r.URL.Path, accountsSegment); index >= 0 {
@@ -119,3 +121,14 @@ func originAllowed(origin string, allowedOrigins []string) bool {
 	}
 	return false
 }
+
+type scopeKey struct{}
+
+// Scope binds cookie creation and deletion to a validated installed API mount.
+func Scope(mount string) func(http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+			next.ServeHTTP(w, r.WithContext(context.WithValue(r.Context(), scopeKey{}, mount)))
+		})
+	}
+}