Elasticsearch::API

This library is part of the elasticsearch-ruby package; please refer to it, unless you want to use this library standalone.

The elasticsearch-api library provides a Ruby implementation of the Elasticsearch REST API.

It does not provide an Elasticsearch client; see the elastic-transport library.

We follow Ruby’s own maintenance policy and officially support all currently maintained versions per Ruby Maintenance Branches.

Language clients are forward compatible; meaning that clients support communicating with greater minor versions of Elasticsearch. Elastic language clients are also backwards compatible with lesser supported minor Elasticsearch versions.

Installation

Install the package from Rubygems:

gem install elasticsearch-api

To use an unreleased version, either add it to your Gemfile for Bundler:

gem 'elasticsearch-api', git: 'git://github.com/elasticsearch/elasticsearch-ruby.git'

or install it from a source code checkout:

git clone https://github.com/elasticsearch/elasticsearch-ruby.git
cd elasticsearch-ruby/elasticsearch-api
bundle install
rake install

Usage

The library is designed as a group of standalone Ruby modules, which can be mixed into a class providing connection to Elasticsearch -- an Elasticsearch client.

Usage with the `elasticsearch` gem

When you use the client from the elasticsearch-ruby package, the library modules have been already included, so you just call the API methods:

require 'elasticsearch'

client = Elasticsearch::Client.new(log: true)

client.index(index: 'myindex', type: 'mytype', id: 1, body: { title: 'Test' })
# => {"_index"=>"myindex", ... "created"=>true}

client.search(index: 'myindex', body: { query: { match: { title: 'test' } } })
# => {"took"=>2, ..., "hits"=>{"total":5, ...}}

Full documentation and examples are included as RDoc annotations in the source code and available online at http://rubydoc.info/gems/elasticsearch-api.

Usage with a custom client

When you want to mix the library into your own client, it must conform to a following contract:

It responds to a perform_request(method, path, params, body, headers) method,
the method returns an object with status, body and headers methods.

A simple client could look like this (with a dependency on active_support to parse the query params):

require 'multi_json'
require 'faraday'
require 'elasticsearch/api'
require 'active_support'

class MySimpleClient
  include Elasticsearch::API

  CONNECTION = ::Faraday::Connection.new url: 'http://localhost:9200'

  def perform_request(method, path, params, body, headers = nil)
    puts "--> #{method.upcase} #{path} #{params} #{body} #{headers}"

    CONNECTION.run_request \
      method.downcase.to_sym,
      path_with_params(path, params),
      ( body ? MultiJson.dump(body): nil ),
      {'Content-Type' => 'application/json'}
  end

  private

  def path_with_params(path, params)
    return path if params.blank?

    case params
    when String
      "#{path}?#{params}"
    when Hash
      "#{path}?#{params.to_query}"
    else
      raise ArgumentError, "Cannot parse params: '#{params}'"
    end
  end
end

client = MySimpleClient.new

p client.cluster.health
# --> GET _cluster/health {}
# => "{"cluster_name":"elasticsearch" ... }"

p client.index index: 'myindex', type: 'mytype', id: 'custom', body: { title: "Indexing from my client" }
# --> PUT myindex/mytype/custom {} {:title=>"Indexing from my client"}
# => "{"ok":true, ... }"

Using JSON Builders

Instead of passing the :body argument as a Ruby Hash, you can pass it as a String, potentially taking advantage of JSON builders such as JBuilder or Jsonify:

require 'jbuilder'

query = Jbuilder.encode do |json|
  json.query do
    json.match do
      json.title do
        json.query    'test 1'
        json.operator 'and'
      end
    end
  end
end

client.search index: 'myindex', body: query

# 2013-06-25 09:56:05 +0200: GET http://localhost:9200/myindex/_search [status:200, request:0.015s, query:0.011s]
# 2013-06-25 09:56:05 +0200: > {"query":{"match":{"title":{"query":"test 1","operator":"and"}}}}
# ...
# => {"took"=>21, ..., "hits"=>{"total"=>1, "hits"=>[{ "_source"=>{"title"=>"Test 1", ...}}]}}

Using Hash Wrappers

For a more comfortable access to response properties, you may wrap it in one of the Hash "object access" wrappers, such as Hashie::Mash:

require 'hashie'

response = client.search index: 'myindex',
                         body: {
                           query: { match: { title: 'test' } },
                           aggregations: { tags: { terms: { field: 'tags' } } }
                         }

mash = Hashie::Mash.new response

mash.hits.hits.first._source.title
# => 'Test'

mash.aggregations.tags.terms.first
# => #<Hashie::Mash count=3 term="z">

Using a Custom JSON Serializer

The library uses the MultiJson gem by default, but allows you to set a custom JSON library, provided it uses the standard load/dump interface:

Elasticsearch::API.settings[:serializer] = JrJackson::Json
Elasticsearch::API.serializer.dump({foo: 'bar'})
# => {"foo":"bar"}

Development

To work on the code, clone and bootstrap the main repository first -- please see instructions in the main README.

To run tests, launch a testing cluster -- again, see instructions in the main README -- and use the Rake tasks:

time rake test:unit
time rake test:integration

We run the test suite for Elasticsearch's Rest API tests. You can read more about this in the test runner README.

The rest_api needs the test files from Elasticsearch. You can run the rake task to download the test artifacts in the root folder of the project. This task needs a running cluster to determine which version and build hash of Elasticsearch to use and test against. TEST_ES_SERVER=http://localhost:9200 rake elasticsearch:download_artifacts. This will download the necessary files used for the integration tests to ./tmp.

License

This software is licensed under the Apache 2 license.