How To Setup Elasticsearch In Your Rails Application In Development

August 16, 2014

Step 1 – Install elasticsearch

If you haven’t installed elasticsearch on your local development machine, this article tells you how to do so in Linux

Step 2 – Add the right ruby gems for the Ruby elasticsearch client in your Gemfile and bundle install

gem 'elasticsearch-rails'
gem 'elasticsearch-model'
gem 'elasticsearch-extensions'

Step 3 – Configure indexes in your Rails model(s)

class User < ActiveRecord::Base
  include Elasticsearch::Model
  include Elasticsearch::Model::Callbacks
  settings index: { number_of_shards: 2 } do
    mappings dynamic: 'false' do
      indexes :name, analyzer: 'english', index_options: 'offsets'
      indexes :email, analyzer: 'english', index_options: 'offsets'
      indexes :hobbies, analyzer: 'english', index_options: 'offsets'
    end
  end
  def self.search_users(search_words)
    User.import
    response = User.search(
      size: 20,
      query: {
            match: {
                "_all" => {
                  "query" => search_words,
                  "operator" => "or"
                }
            }
        }
    )
    response.records
  end
end

Step 4 – Create / refresh the index

Start up the rails console in development mode and issue the following commands:

User.__elasticsearch__.create_index! force: true
User.__elasticsearch__.refresh_index!

These commands will setup a search index with your desired configuration in the User model above. If you ever change your settings, you’ll need to reissue these commands. I hope to come back and update these instructions with a more automated process soon.

Choosing the query type

In the User model, I called the search method on the User model to return 20 results (see the size: 20 setting). The _all keyword tells elasticsearch to match all documents using the query search_words and “or” logic. For example if search_words is “Joe Smith”, elasticsearch searches for documents with the words Joe OR Smith. The query I use above should provide you what you need for simple searches.