logstash-filter-augment

logstash-filter-augment Plugin

This is a plugin for Logstash.

It is fully free and fully open source. The license is Apache 2.0, meaning you are pretty much free to use it however you want in whatever way.

It can be used to augment events in logstash from config, CSV file, JSON file, or yaml files. This differs from the translate plugin in that it can add multiple fields to the event based on one lookup. For example say you have a geocode file that maps store numbers to coordinates. Using this plugin you can add a location.latitude and location.longitude to your event based on a simple lookup.

Documentation

logstash-filter-augment is a logstash plugin for augmenting events with data from a config file or exteral file (in CSV, JSON, or YAML format). The filter takes a field parameter that specifies what is being looked up. Based on configuration, it will find the object that is referred to and add the fields of that object to your event.

In the case of a CSV file, you'll want to specify the csv_key to tell it which field of the file is the key (it'll default to the first column in the CSV if you don't specify). If your CSV file doesn't contain a header row, you'll need to set the csv_header to be an array of the column names. If you do have a header, you can still specify the csv_header, but be sure to also specify that you want to csv_first_line => ignore.

In the case of JSON, you can provide a simple dictionary that maps the keys to the objects:

{
  "200": { "color": "green", "message": "ok" }
}

or in Array format:

[
{"code": 200, "color": "green", "message": "ok"}
]

but then you'll have to provide a json_key => "code" parameter in your config file to let it know which field you want to use for lookups.

YAML works the same as JSON -- you can specify either a dictionary or an array:

200:
  color: green
  message: ok
404:
  color: red
  message: not found

or

- code: 200
  color: green
  message: ok
- code: 404
  color: red
  message: not found

but again, you'll need to specify the yaml_key => "code"

Finally you can configure logstash-filter-augment statically with a dictionary:

    dictionary => {
        "200" => {
          "color" => "green"
          "message" => "OK"
        }
        "404" => {
          "color" => "red"
          "message" => "Missing"
        }
      }
      default => {
        "color" => "orange"
        "message" => "not found"
      }
  }

If you choose this route, be careful that you quote your keys or you could end up with weird logstash errors.

config parameters

parameter	required (default)	Description
field	Yes	the field of the event to look up in the dictionary
dictionary_path	Yes if dictionary isn't provided	The list of files to load
dictionary_type	No (auto)	The type of files provided on dictionary_path. Allowed values are auto, csv, json, yaml, and yml
dictionary	Yes if dictionary_path isn't provided	A dictionary to use. See example above
csv_header	No	The header fields of the csv_file
csv_first_line	No (auto)	indicates what to do with the first line of the file. Valid values are ignore, header, data, and auto. auto treats the first line as data if csv_header is set or header if it isn't
csv_key	No	On CSV files, which field name is the key. Defaults to the first column of the file if not set
csv_remove_key	No(true)	Remove the key from the object. You might want to set this to false if you don't have a default set so that you know which records were matched
csv_col_sep	No(,)	Change the column seperator for CSV files. If you need to use tabs, you have to embed a real tab in the quotes
csv_quote_char	No(")	Change the quote character for CSV files
json_key	Yes, if array	The field of the json objects to use as a key for the dictionary
json_remove_key	No	Similar to csv_remove_key
yaml_key	Yes, if array	The field of the YAML objects to use as a key for the dictionary
yaml_remove_key	No	Similar to csv_remove_key
augment_fields	No (all fields)	The fields to copy from the object to the target. If this is specified, only these fields will be copied.
ignore_fields	No	If this list is specified and augment_fields isn't, then these fields will not be copied
default	No	A dictionary of fields to add to the target if the key isn't in the data
target	No ("")	Where to target the fields. If this is left as the default "", it targets the event itself. Otherwise you can specify a valid event selector. For example, [user][location] Would set user.location.{fields from object}
refresh_interval	No (60)	The number of seconds between checking to see if the file has been modified. Set to -1 to disable checking, set to 0 to check on every event (not recommended)

Use Cases

Geocoding by key

If you have a field that can be used to lookup a location and you have a location file, you could configure this way:

   augment {
      field => "store"
      target => "[location]"
      dictionary_path => "geocode.csv"
      csv_header => ["id","lat","lon"]
      csv_key => "id"
      csv_first_line => "data"
   }

and then be sure that your mapping / mapping template changes "location" into a geo_point

Attach multiple pieces of user data based on user key

  augment {
    field => "username"
    dictionary_path => ["users1.csv", "users2.csv"]
    csv_header => ["username","fullName","address1","address2","city","state","zipcode"]
    csv_key => "id"
    csv_first_line => "ignore"
  }

Developing

1. Plugin Developement and Testing

Code

• To get started, you'll need JRuby with the Bundler gem installed.

• Install dependencies

bundle install

Test

• Update your dependencies

bundle install

• Run tests

bundle exec rspec

2. Running your unpublished Plugin in Logstash

2.1 Run in a local Logstash clone

• Edit Logstash Gemfile and add the local plugin path, for example:

gem "logstash-filter-augment", :path => "/your/local/logstash-filter-augment"

• Install plugin

bin/logstash-plugin install --no-verify

• Run Logstash with your plugin

bin/logstash -e 'filter {augment {}}'

At this point any modifications to the plugin code will be applied to this local Logstash setup. After modifying the plugin, simply rerun Logstash.

2.2 Run in an installed Logstash

You can use the same 2.1 method to run your plugin in an installed Logstash by editing its Gemfile and pointing the :path to your local plugin development directory or you can build the gem and install it using:

• Build your plugin gem

gem build logstash-filter-augment.gemspec

• Install the plugin from the Logstash home

bin/logstash-plugin install /your/local/plugin/logstash-filter-augment.gem

• Start Logstash and proceed to test the plugin

Contributing

All contributions are welcome: ideas, patches, documentation, bug reports, complaints, and even something you drew up on a napkin.

Programming is not a required skill. Whatever you've seen about open source and maintainers or community members saying "send patches or die" - you will not see that here.

It is more important to the community that you are able to contribute.

For more information about contributing, see the CONTRIBUTING file.