Alter filter plugin

Sets the value of field_name to the first nonnull expression among its arguments.

Example:

    filter {
      alter {
        coalesce => [
             "field_name", "value1", "value2", "value3", ...
        ]
      }
    }

Change the content of the field to the specified value if the actual content is equal to the expected one.

Example:

    filter {
      alter {
        condrewrite => [
             "field_name", "expected_value", "new_value",
             "field_name2", "expected_value2", "new_value2",
             ....
           ]
      }
    }

Change the content of the field to the specified value if the content of another field is equal to the expected one.

Example:

    filter {
      alter {
        condrewriteother => [
             "field_name", "expected_value", "field_name_to_change", "value",
             "field_name2", "expected_value2", "field_name_to_change2", "value2",
             ....
        ]
      }
    }

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

# You can also add multiple fields at once:
filter {
  PLUGIN_NAME {
    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.

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 {
  PLUGIN_NAME {
    add_tag => [ "foo_%{somefield}" ]
  }
}

# You can also add multiple tags at once:
filter {
  PLUGIN_NAME {
    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).

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.

Add a unique ID to the plugin instance, this ID is used for tracking information for a specific configuration of the plugin.

output {
 stdout {
   id => "ABC"
 }
}

If you don’t explicitely set this variable Logstash will generate a unique name.

Call the filter flush method at regular interval. Optional.

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 {
  PLUGIN_NAME {
    remove_field => [ "foo_%{somefield}" ]
  }
}

# You can also remove multiple fields at once:
filter {
  PLUGIN_NAME {
    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.

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 {
  PLUGIN_NAME {
    remove_tag => [ "foo_%{somefield}" ]
  }
}

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