feat: 为 Nginx 配置 Docker 内部 DNS 解析器并使用变量代理后端服务

nginx.conf

@@ -25,9 +25,13 @@ server {
         add_header Cache-Control "public, immutable";
     }
 
+    # 使用 Docker 内部 DNS 解析器
+    resolver 127.0.0.11 valid=30s;
+
     # API 代理到后端
     location /api/ {
-        proxy_pass http://backend:2612;
+        set $backend_host "backend:2612";
+        proxy_pass http://$backend_host;
         proxy_http_version 1.1;
         proxy_set_header Upgrade $http_upgrade;
         proxy_set_header Connection 'upgrade';
@@ -45,7 +49,8 @@ server {
 
     # 健康检查端点
     location /health {
-        proxy_pass http://backend:2612/health;
+        set $backend_host "backend:2612";
+        proxy_pass http://$backend_host/health;
         access_log off;
     }