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Environment filter plugin

Environment filter plugin

Plugin version: v3.0.3
Released on: 2017-11-07
Changelog

For other versions, see the Versioned plugin docs.

Installation

For plugins not bundled by default, it is easy to install by running bin/logstash-plugin install logstash-filter-environment. See Working with plugins for more details.

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

This filter stores environment variables as subfields in the @metadata field. You can then use these values in other parts of the pipeline.

Adding environment variables is as easy as: filter { environment { add_metadata_from_env ⇒ { "field_name" ⇒ "ENV_VAR_NAME" } } }

Accessing stored environment variables is now done through the @metadata field:

["@metadata"]["field_name"]

This would reference field field_name, which in the above example references the ENV_VAR_NAME environment variable.

Previous versions of this plugin put the environment variables as fields at the root level of the event. Current versions make use of the @metadata field, as outlined. You have to change add_field_from_env in the older versions to add_metadata_from_env in the newer version.

Environment Filter Configuration Options

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

Setting	Input type	Required
`add_metadata_from_env`	hash	No

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

`add_metadata_from_env`

Value type is hash
Default value is {}

Specify a hash of field names and the environment variable name with the value you want imported into Logstash. For example:

add_metadata_from_env => { "field_name" => "ENV_VAR_NAME" }

or

add_metadata_from_env => {
  "field1" => "ENV1"
  "field2" => "ENV2"
  # "field_n" => "ENV_n"
}

Common options

These configuration options are supported by all filter plugins:

Setting	Input type	Required
`add_field`	hash	No
`add_tag`	array	No
`enable_metric`	boolean	No
`id`	string	No
`periodic_flush`	boolean	No
`remove_field`	array	No
`remove_tag`	array	No

`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 {
      environment {
        add_field => { "foo_%{somefield}" => "Hello world, from %{host}" }
      }
    }

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

    # You can also add multiple tags at once:
    filter {
      environment {
        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 environment filters. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

    filter {
      environment {
        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`

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. Fields names can be dynamic and include parts of the event using the %{field} Example:

    filter {
      environment {
        remove_field => [ "foo_%{somefield}" ]
      }
    }

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

    # You can also remove multiple tags at once:
    filter {
      environment {
        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.

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