Xml filter plugin

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  • Plugin version: v4.2.1
  • Released on: 2024-10-29
  • Changelog

For other versions, see the Versioned plugin docs.

Getting Help

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For questions about the plugin, open a topic in the Discuss forums. For bugs or feature requests, open an issue in Github. For the list of Elastic supported plugins, please consult the Elastic Support Matrix.

Description

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XML filter. Takes a field that contains XML and expands it into an actual datastructure.

Xml Filter Configuration Options

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This plugin supports the following configuration options plus the Common Options described later.

Also see Common Options for a list of options supported by all filter plugins.

 

force_array

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  • Value type is boolean
  • Default value is true

By default the filter will force single elements to be arrays. Setting this to false will prevent storing single elements in arrays.

force_content

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  • Value type is boolean
  • Default value is false

By default the filter will expand attributes differently from content inside of tags. This option allows you to force text content and attributes to always parse to a hash value.

namespaces

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  • Value type is hash
  • Default value is {}

By default only namespaces declarations on the root element are considered. This allows to configure all namespace declarations to parse the XML document.

Example:

filter {
  xml {
    namespaces => {
      "xsl" => "http://www.w3.org/1999/XSL/Transform"
      "xhtml" => "http://www.w3.org/1999/xhtml"
    }
  }
}

parse_options

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  • Value type is string
  • There is no default value for this setting.

Setting XML parse options allows for more control of the parsing process. By default the parser is not strict and thus accepts some invalid content. Currently supported options are:

  • strict - forces the parser to fail early instead of accumulating errors when content is not valid xml.

Control characters such as ASCII 0x0 are not allowed and always result in non-valid XML.

When XML content is not valid, it will be tagged as _xmlparsefailure.

XML specs:

remove_namespaces

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  • Value type is boolean
  • Default value is false

Remove all namespaces from all nodes in the document. Of course, if the document had nodes with the same names but different namespaces, they will now be ambiguous.

source

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  • This is a required setting.
  • Value type is string
  • There is no default value for this setting.

Config for xml to hash is:

    source => source_field

For example, if you have the whole XML document in your message field:

    filter {
      xml {
        source => "message"
      }
    }

The above would parse the XML from the message field.

store_xml

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  • Value type is boolean
  • Default value is true

By default the filter will store the whole parsed XML in the destination field as described above. Setting this to false will prevent that.

suppress_empty

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  • Value type is boolean
  • Default value is true

By default, output nothing if the element is empty. If set to false, empty element will result in an empty hash object.

target

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  • Value type is string
  • There is no default value for this setting.

Define target for placing the data

For example if you want the data to be put in the doc field:

    filter {
      xml {
        target => "doc"
      }
    }

XML in the value of the source field will be expanded into a datastructure in the target field. Note: if the target field already exists, it will be overridden. Required if store_xml is true (which is the default).

xpath

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  • Value type is hash
  • Default value is {}

xpath will additionally select string values (non-strings will be converted to strings with Ruby’s to_s function) from parsed XML (using each source field defined using the method above) and place those values in the destination fields. Configuration:

xpath => [ "xpath-syntax", "destination-field" ]

Values returned by XPath parsing from xpath-syntax will be put in the destination field. Multiple values returned will be pushed onto the destination field as an array. As such, multiple matches across multiple source fields will produce duplicate entries in the field.

Additional XPath resources
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For more information on XPath, see https://www.w3schools.com/xml/xml_xpath.asp.

The XPath functions are particularly powerful.

Common Options

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The following configuration options are supported by all filter plugins:

add_field

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  • Value type is hash
  • Default value is {}

If this filter is successful, add any arbitrary fields to this event. Field names can be dynamic and include parts of the event using the %{field}.

Example:

    filter {
      xml {
        add_field => { "foo_%{somefield}" => "Hello world, from %{host}" }
      }
    }
    # You can also add multiple fields at once:
    filter {
      xml {
        add_field => {
          "foo_%{somefield}" => "Hello world, from %{host}"
          "new_field" => "new_static_value"
        }
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would add field foo_hello if it is present, with the value above and the %{host} piece replaced with that value from the event. The second example would also add a hardcoded field.

add_tag

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  • Value type is array
  • Default value is []

If this filter is successful, add arbitrary tags to the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

    filter {
      xml {
        add_tag => [ "foo_%{somefield}" ]
      }
    }
    # You can also add multiple tags at once:
    filter {
      xml {
        add_tag => [ "foo_%{somefield}", "taggedy_tag"]
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would add a tag foo_hello (and the second example would of course add a taggedy_tag tag).

enable_metric

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  • Value type is boolean
  • Default value is true

Disable or enable metric logging for this specific plugin instance. By default we record all the metrics we can, but you can disable metrics collection for a specific plugin.

  • Value type is string
  • There is no default value for this setting.

Add a unique ID to the plugin configuration. If no ID is specified, Logstash will generate one. It is strongly recommended to set this ID in your configuration. This is particularly useful when you have two or more plugins of the same type, for example, if you have 2 xml filters. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

    filter {
      xml {
        id => "ABC"
      }
    }

Variable substitution in the id field only supports environment variables and does not support the use of values from the secret store.

periodic_flush

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  • Value type is boolean
  • Default value is false

Call the filter flush method at regular interval. Optional.

remove_field

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  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary fields from this event. Fields names can be dynamic and include parts of the event using the %{field} Example:

    filter {
      xml {
        remove_field => [ "foo_%{somefield}" ]
      }
    }
    # You can also remove multiple fields at once:
    filter {
      xml {
        remove_field => [ "foo_%{somefield}", "my_extraneous_field" ]
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would remove the field with name foo_hello if it is present. The second example would remove an additional, non-dynamic field.

remove_tag

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  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary tags from the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

    filter {
      xml {
        remove_tag => [ "foo_%{somefield}" ]
      }
    }
    # You can also remove multiple tags at once:
    filter {
      xml {
        remove_tag => [ "foo_%{somefield}", "sad_unwanted_tag"]
      }
    }

If the event has field "somefield" == "hello" this filter, on success, would remove the tag foo_hello if it is present. The second example would remove a sad, unwanted tag as well.