FEATURE: Support backup uploads/downloads directly to/from S3.

This reverts commit 3c59106bac4d79f39981bda3ff9db7786c1a78a0.

lib/backup_restore/s3_backup_store.rb

@@ -0,0 +1,95 @@
+require_dependency "backup_restore/backup_store"
+require_dependency "s3_helper"
+
+module BackupRestore
+  class S3BackupStore < BackupStore
+    DOWNLOAD_URL_EXPIRES_AFTER_SECONDS ||= 15
+    UPLOAD_URL_EXPIRES_AFTER_SECONDS ||= 21_600 # 6 hours
+
+    def initialize(opts = {})
+      s3_options = S3Helper.s3_options(SiteSetting)
+      s3_options.merge!(opts[:s3_options]) if opts[:s3_options]
+      @s3_helper = S3Helper.new(SiteSetting.s3_backup_bucket, '', s3_options)
+    end
+
+    def remote?
+      true
+    end
+
+    def file(filename, include_download_source: false)
+      obj = @s3_helper.object(filename)
+      create_file_from_object(obj, include_download_source) if obj.exists?
+    end
+
+    def delete_file(filename)
+      obj = @s3_helper.object(filename)
+      obj.delete if obj.exists?
+    end
+
+    def download_file(filename, destination_path, failure_message = nil)
+      unless @s3_helper.object(filename).download_file(destination_path)
+        raise failure_message&.to_s || "Failed to download file"
+      end
+    end
+
+    def upload_file(filename, source_path, content_type)
+      obj = @s3_helper.object(filename)
+      raise BackupFileExists.new if obj.exists?
+
+      obj.upload_file(source_path, content_type: content_type)
+    end
+
+    def generate_upload_url(filename)
+      obj = @s3_helper.object(filename)
+      raise BackupFileExists.new if obj.exists?
+
+      presigned_url(obj, :put, UPLOAD_URL_EXPIRES_AFTER_SECONDS)
+    end
+
+    private
+
+    def unsorted_files
+      objects = []
+
+      @s3_helper.list.each do |obj|
+        if obj.key.match?(/\.t?gz$/i)
+          objects << create_file_from_object(obj)
+        end
+      end
+
+      objects
+    rescue Aws::Errors::ServiceError => e
+      Rails.logger.warn("Failed to list backups from S3: #{e.message.presence || e.class.name}")
+      raise StorageError
+    end
+
+    def create_file_from_object(obj, include_download_source = false)
+      BackupFile.new(
+        filename: File.basename(obj.key),
+        size: obj.size,
+        last_modified: obj.last_modified,
+        source: include_download_source ? presigned_url(obj, :get, DOWNLOAD_URL_EXPIRES_AFTER_SECONDS) : nil
+      )
+    end
+
+    def presigned_url(obj, method, expires_in_seconds)
+      ensure_cors!
+      obj.presigned_url(method, expires_in: expires_in_seconds)
+    end
+
+    def ensure_cors!
+      rule = {
+        allowed_headers: ["*"],
+        allowed_methods: ["PUT"],
+        allowed_origins: [Discourse.base_url_no_prefix],
+        max_age_seconds: 3000
+      }
+
+      @s3_helper.ensure_cors!([rule])
+    end
+
+    def cleanup_allowed?
+      !SiteSetting.s3_disable_cleanup
+    end
+  end
+end