常見的處理器使用案例

剖析 JSON 日誌、標準化欄位名稱，以及新增環境資訊：

processor:
  - parse_json: {}
  - rename_keys:
      entries:
        - from_key: "timestamp"
          to_key: "@timestamp"
        - from_key: "log_level"
          to_key: "level"
  - add_entries:
      entries:
        - key: "environment"
          value: "production"
        - key: "application"
          value: "payment-service"

標準化狀態碼並移除敏感資料：

processor:
  - uppercase_string:
      with_keys: ["status", "method"]
  - delete_entries:
      with_keys: ["credit_card", "password"]
  - substitute_string:
      entries:
        - source: "status"
          from: "SUCCESS"
          to: "OK"

擷取用於分析的使用者資訊和格式：

processor:
  - extract_value:
      entries:
        - source: "user_agent"
          target: "browser"
          from: "(?<browser>Chrome|Firefox|Safari)"
          to: "${browser}"
  - lowercase_string:
      with_keys: ["browser"]
  - move_keys:
      entries:
        - from_key: "browser"
          to_key: "user_data.browser"

使用入門級when條件根據日誌嚴重性新增不同的中繼資料：

processor:
  - add_entries:
      entries:
        - key: "alert_level"
          value: "critical"
          when: "log.level == 'ERROR'"
        - key: "alert_level"
          value: "info"
          when_else: "log.level == 'ERROR'"

從第三方來源篩選除錯和追蹤日誌項目，以減少雜訊和儲存成本：

processor:
  - drop_events:
      when: "log.level in {'DEBUG', 'TRACE'}"
      handle_expression_failure: "skip"

僅在環境為生產環境時移除敏感欄位：

processor:
  - delete_entries:
      with_keys: ["password", "api_key", "ssn"]
      when: "environment in {'prod', 'staging'}"