[Awesome Ruby Gem] Use elasticsearch gems to provide Elasticsearch integrations for ActiveModel/Record and Ruby on Rails

Posted on 2021-08-14 Edited on 2024-09-12 In Programming Language , Ruby , Awesome Ruby Gem Views: Word count in article: 4.5k Reading time ≈ 4 mins.

Elasticsearch

The elasticsearch gems provides a low-level client for communicating with an Elasticsearch cluster, fully compatible with other official clients.

This repository contains various Ruby and Rails integrations for Elasticsearch:

ActiveModel integration with adapters for ActiveRecord and Mongoid
Repository pattern based persistence layer for Ruby objects
Enumerable-based wrapper for search results
ActiveRecord::Relation-based wrapper for returning search results as records
Convenience model methods such as search, mapping, import, etc
Rake tasks for importing the data
Support for Kaminari and WillPaginate pagination
Integration with Rails’ instrumentation framework
Templates for generating example Rails application
Elasticsearch client and Ruby API is provided by the elasticsearch-ruby project.

This project is split into three separate gems:

elasticsearch-modelelasticsearch-rails/README.md at master · elastic/elasticsearch-rails - https://github.com/elastic/elasticsearch-rails/blob/master/elasticsearch-model/README.md, which contains search integration for Ruby/Rails models such as ActiveRecord::Base and Mongoid,
elasticsearch-persistence elasticsearch-rails/elasticsearch-persistence at master · elastic/elasticsearch-rails - https://github.com/elastic/elasticsearch-rails/tree/master/elasticsearch-persistence, which provides a standalone persistence layer for Ruby/Rails objects and models
elasticsearch-rails elasticsearch-rails/elasticsearch-model at master · elastic/elasticsearch-rails - https://github.com/elastic/elasticsearch-rails/tree/master/elasticsearch-model, which contains various features for Ruby on Rails applications

Installation

You can install it as a gem:

1	$ gem install elasticsearch-rails

or add it into a Gemfile (Bundler):

# Gemfile

# elastic/elasticsearch-rails: Elasticsearch integrations for ActiveModel/Record and Ruby on Rails
# https://github.com/elastic/elasticsearch-rails
gem 'elasticsearch-rails', '7.2.0'

Then, run bundle install.

1	$ bundle install

Usages

Example of a basic integration into an ActiveRecord-based model:

require 'elasticsearch/model'

class Article < ActiveRecord::Base
  include Elasticsearch::Model
  include Elasticsearch::Model::Callbacks
end

# Index creation right at import time is not encouraged.
# Typically, you would call create_index! asynchronously (e.g. in a cron job)
# However, we are adding it here so that this usage example can run correctly.
Article.__elasticsearch__.create_index!
Article.import

@articles = Article.search('foobar').records

You can generate a simple Ruby on Rails application with a single command (see the other available templates). You’ll need to have an Elasticsearch cluster running on your system before generating the app. The easiest way of getting this set up is by running it with Docker with this command:

$ docker run \
    --name elasticsearch-rails-searchapp \
    --publish 9200:9200 \
    --env "discovery.type=single-node" \
    --env "cluster.name=elasticsearch-rails" \
    --env "cluster.routing.allocation.disk.threshold_enabled=false" \
    --rm \
    docker.elastic.co/elasticsearch/elasticsearch-oss:7.6.0

Once Elasticsearch is running, you can generate the simple app with this command:

1	$ rails new searchapp --skip --skip-bundle --template https://raw.github.com/elasticsearch/elasticsearch-rails/master/elasticsearch-rails/lib/rails/templates/01-basic.rb

Example of using Elasticsearch as a repository for a Ruby domain object:

class Article
  attr_accessor :title
end

require 'elasticsearch/persistence'
repository = Elasticsearch::Persistence::Repository.new

repository.save Article.new(title: 'Test')
# POST http://localhost:9200/repository/article
# => {"_index"=>"repository", "_type"=>"article", "_id"=>"Ak75E0U9Q96T5Y999_39NA", ...}