Translate filter plugin v3.2.2

  • Plugin version: v3.2.2
  • Released on: 2018-08-28
  • Changelog

For other versions, see the overview list.

To learn more about Logstash, see the Logstash Reference.

Getting Help

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

A general search and replace tool that uses a configured hash and/or a file to determine replacement values. Currently supported are YAML, JSON, and CSV files. Each dictionary item is a key value pair.

The dictionary entries can be specified in one of two ways: First, the dictionary configuration item may contain a hash representing the mapping. Second, an external file (readable by logstash) may be specified in the dictionary_path configuration item. These two methods may not be used in conjunction; it will produce an error.

Operationally, for each event, the value from the field setting is tested against the dictionary and if it matches exactly (or matches a regex when regex configuration item has been enabled), the matched value is put in the destination field, but on no match the fallback setting string is used instead.

Example:

    filter {
      translate {
        field => "[http_status]"
        destination => "[http_status_description]"
        dictionary => {
          "100" => "Continue"
          "101" => "Switching Protocols"
          "200" => "OK"
          "500" => "Server Error"
        }
        fallback => "I'm a teapot"
      }
    }

Occasionally, people find that they have a field with a variable sized array of values or objects that need some enrichment. The iterate_on setting helps in these cases.

Alternatively, for simple string search and replacements for just a few values you might consider using the gsub function of the mutate filter.

It is possible to provide multi-valued dictionary values. When using a YAML or JSON dictionary, you can have the value as a hash (map) or an array datatype. When using a CSV dictionary, multiple values in the translation must be extracted with another filter e.g. Dissect or KV. Note that the fallback is a string so on no match the fallback setting needs to formatted so that a filter can extract the multiple values to the correct fields.

File based dictionaries are loaded in a separate thread using a scheduler. If you set a refresh_interval of 300 seconds (5 minutes) or less then the modified time of the file is checked before reloading. Very large dictionaries are supported, internally tested at 100 000 key/values, and we minimise the impact on throughput by having the refresh in the scheduler thread. Any ongoing modification of the dictionary file should be done using a copy/edit/rename or create/rename mechanism to avoid the refresh code from processing half-baked dictionary content.

Translate Filter Configuration Options

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.

 

destination

  • Value type is string
  • Default value is "translation"

The destination field you wish to populate with the translated code. The default is a field named translation. Set this to the same value as source if you want to do a substitution, in this case filter will allways succeed. This will clobber the old value of the source field!

dictionary

  • Value type is hash
  • Default value is {}

The dictionary to use for translation, when specified in the logstash filter configuration item (i.e. do not use the @dictionary_path file).

Example:

    filter {
      translate {
        dictionary => {
          "100"         => "Continue"
          "101"         => "Switching Protocols"
          "merci"       => "thank you"
          "old version" => "new version"
        }
      }
    }
Note

It is an error to specify both dictionary and dictionary_path.

dictionary_path

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

The full path of the external dictionary file. The format of the table should be a standard YAML, JSON, or CSV. Make sure you specify any integer-based keys in quotes. For example, the YAML file should look something like this:

    "100": Continue
    "101": Switching Protocols
    merci: gracias
    old version: new version
Note

It is an error to specify both dictionary and dictionary_path.

The currently supported formats are YAML, JSON, and CSV. Format selection is based on the file extension: json for JSON, yaml or yml for YAML, and csv for CSV. The CSV format expects exactly two columns, with the first serving as the original text (lookup key), and the second column as the translation.

exact

  • Value type is boolean
  • Default value is true

When exact => true, the translate filter will populate the destination field with the exact contents of the dictionary value. When exact => false, the filter will populate the destination field with the result of any existing destination field’s data, with the translated value substituted in-place.

For example, consider this simple translation.yml, configured to check the data field:

    foo: bar

If logstash receives an event with the data field set to foo, and exact => true, the destination field will be populated with the string bar. If exact => false, and logstash receives the same event, the destination field will be also set to bar. However, if logstash receives an event with the data field set to foofing, the destination field will be set to barfing.

Set both exact => true AND regex => `true if you would like to match using dictionary keys as regular expressions. A large dictionary could be expensive to match in this case.

fallback

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

In case no translation occurs in the event (no matches), this will add a default translation string, which will always populate field, if the match failed.

For example, if we have configured fallback => "no match", using this dictionary:

    foo: bar

Then, if logstash received an event with the field foo set to bar, the destination field would be set to bar. However, if logstash received an event with foo set to nope, then the destination field would still be populated, but with the value of no match. This configuration can be dynamic and include parts of the event using the %{field} syntax.

field

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

The name of the logstash event field containing the value to be compared for a match by the translate filter (e.g. message, host, response_code).

If this field is an array, only the first value will be used.

iterate_on

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

When the value that you need to perform enrichment on is a variable sized array then specify the field name in this setting. This setting introduces two modes, 1) when the value is an array of strings and 2) when the value is an array of objects (as in JSON object). In the first mode, you should have the same field name in both field and iterate_on, the result will be an array added to the field specified in the destination setting. This array will have the looked up value (or the fallback value or nil) in same ordinal position as each sought value. In the second mode, specify the field that has the array of objects in iterate_on then specify the field in each object that provides the sought value with field and the field to write the looked up value (or the fallback value) to with destination.

For a dictionary of:

  100,Yuki
  101,Rupert
  102,Ahmed
  103,Kwame

Example of Mode 1

filter {
  translate {
    iterate_on => "[collaborator_ids]"
    field      => "[collaborator_ids]"
    destination => "[collaborator_names]"
    fallback => "Unknown"
  }
}

Before

{
  "collaborator_ids": [100,103,110,102]
}

After

{
  "collaborator_ids": [100,103,110,102],
  "collabrator_names": ["Yuki","Kwame","Unknown","Ahmed"]
}

Example of Mode 2

filter {
  translate {
    iterate_on => "[collaborators]"
    field      => "[id]"
    destination => "[name]"
    fallback => "Unknown"
  }
}

Before

{
  "collaborators": [
    {
      "id": 100
    },
    {
      "id": 103
    },
    {
      "id": 110
    },
    {
      "id": 101
    }
  ]
}

After

{
  "collaborators": [
    {
      "id": 100,
      "name": "Yuki"
    },
    {
      "id": 103,
      "name": "Kwame"
    },
    {
      "id": 110,
      "name": "Unknown"
    },
    {
      "id": 101,
      "name": "Rupert"
    }
  ]
}

override

  • Value type is boolean
  • Default value is false

If the destination (or target) field already exists, this configuration item specifies whether the filter should skip translation (default) or overwrite the target field value with the new translation value.

refresh_interval

  • Value type is number
  • Default value is 300

When using a dictionary file, this setting will indicate how frequently (in seconds) logstash will check the dictionary file for updates. A value of zero or less will disable refresh.

regex

  • Value type is boolean
  • Default value is false

If you’d like to treat dictionary keys as regular expressions, set regex => true. Note: this is activated only when exact => true.

refresh_behaviour

  • Value type is string
  • Default value is merge

When using a dictionary file, this setting indicates how the update will be executed. Setting this to merge causes the new dictionary to be merged into the old one. This means same entry will be updated but entries that existed before but not in the new dictionary will remain after the merge; replace causes the whole dictionary to be replaced with a new one (deleting all entries of the old one on update).

Common Options

The following configuration options are supported by all filter plugins:

add_field

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

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

  • 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.

id

  • 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 translate filters. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

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

periodic_flush

  • Value type is boolean
  • Default value is false

Call the filter flush method at regular interval. Optional.

remove_field

  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary fields from this event. Example:

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

  • 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 {
  translate {
    remove_tag => [ "foo_%{somefield}" ]
  }
}
# You can also remove multiple tags at once:
filter {
  translate {
    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. :plugin: translate :type: filter