fix: update sitemap retrieval logic

- Change from using `get_object` to `head_object` to check if the
  sitemap file exists before attempting to retrieve it.
- Implement a presigned URL for accessing the sitemap, which is valid
  for 15 minutes.
- Set cache headers to allow for 1 hour of caching.
- Improved logging for better error tracking and debugging.

This change enhances the efficiency of sitemap retrieval by reducing
unnecessary data transfer and provides a more secure way to access
the sitemaps through presigned URLs. It also improves error handling
by logging specific errors related to missing sitemaps.

app/controllers/sitemaps_controller.rb

@@ -12,26 +12,39 @@ class SitemapsController < ApplicationController
     Rails.logger.error "S3 Error: #{e.message}"
     render status: :internal_server_error
   end
+
   def show
     path = params[:path]
-    Rails.logger.info "Sitemap: #{path}"
+    key = "sitemaps/#{path}"
+
+    Rails.logger.info "Requesting sitemap: #{path}"
 
     begin
-      response = s3_client.get_object(
+      # 检查文件是否存在
+      s3_client.head_object(
         bucket: @bucket_name,
-        key: "sitemaps/#{path}"
+        key: key
       )
 
-      expires_in 12.hours, public: true
-      content_type = response.content_type || "application/xml"
-
-      send_data(
-        response.body.read,
-        filename: path,
-        type: content_type,
-        disposition: "inline"
+      # 生成预签名URL，设置15分钟有效期
+      signer = Aws::S3::Presigner.new(client: s3_client)
+      url = signer.presigned_url(
+        :get_object,
+        bucket: @bucket_name,
+        key: key,
+        expires_in: 15 * 60, # 15 minutes
+        # response_content_type: 'application/xml', # 确保正确的内容类型
+        response_content_disposition: "inline" # 在浏览器中直接显示
       )
-    rescue Aws::S3::Errors::NoSuchKey
+
+      # 设置缓存头
+      response.headers["Cache-Control"] = "public, max-age=3600" # 1小时缓存
+
+      # 重定向到预签名URL
+      redirect_to url, allow_other_host: true, status: :found
+
+    rescue Aws::S3::Errors::NotFound
+      Rails.logger.error "Sitemap not found: #{path}"
       render status: :not_found
     rescue Aws::S3::Errors::ServiceError => e
       Rails.logger.error "S3 Error: #{e.message}"
@@ -39,6 +52,33 @@ class SitemapsController < ApplicationController
     end
   end
 
+  # def show
+  #  path = params[:path]
+  #  Rails.logger.info "Sitemap: #{path}"
+
+  #  begin
+  #    response = s3_client.get_object(
+  #      bucket: @bucket_name,
+  #      key: "sitemaps/#{path}"
+  #    )
+
+  #    expires_in 12.hours, public: true
+  #    content_type = response.content_type || "application/xml"
+
+  #    send_data(
+  #      response.body.read,
+  #      filename: path,
+  #      type: content_type,
+  #      disposition: "inline"
+  #    )
+  #  rescue Aws::S3::Errors::NoSuchKey
+  #    render status: :not_found
+  #  rescue Aws::S3::Errors::ServiceError => e
+  #    Rails.logger.error "S3 Error: #{e.message}"
+  #    render status: :internal_server_error
+  #  end
+  # end
+
   private
 
   def set_bucket_name