Add Elasticsearch Capabilities to Application

[npendery]

Files it is used in:

• Skill_controller.ex

Possible clients to use:
Tirexs

[joshsmith]

To clarify a little here, the Rails implementation using searchkick looks something like this:

class Skill < ApplicationRecord
  searchkick match: :word_start, searchable: [:title]

  def self.autocomplete(query)
    results = search query
    results.take(5)
  end
end

class SkillsController < ApplicationController
  before_action :doorkeeper_authorize!, only: [:create, :update]

  def index
    if search_params.present?
      skills = Skill.autocomplete(search_params)
    end
  end
end

Thus a query like rub should provide results like Ruby and Ruby on Rails. Similarly, a query like rab would also provide Ruby and Ruby on Rails (assuming no other relevant results), because the fuzziness of the query allows for some fat-fingering on the user side.

I had done some work awhile back to do this manually, and had come up with this:

  def self.query(query)
    terms = query.split(" ")
    terms = terms.map do |term|
      { term: { title: term } }
    end
    results = search query: {
      bool: {
        should: terms
      }
    }
    results.records.take(5)
  end

  settings index: {
    number_of_shards: 1,
    number_of_replicas: 0,
    analysis: {
      filter: {
        autocomplete_filter: {
          type: "nGram",
          min_gram: 1,
          max_gram: 3
        }
      },
      analyzer: {
        autocomplete: {
          type: "custom",
          tokenizer: "standard",
          filter: [ "lowercase", "autocomplete_filter" ]
        }
      }
    }
  } do
    mappings do
      indexes :title, analyzer: "autocomplete", search_analyzer: "standard"
    end
  end

Was not able to get much of it to work, though.

We should look more deeply into the code behind searchkick and figure out precisely what our working code in searchkick is doing behind-the-scenes in ElasticSearch itself.

[paulsullivanjr]

I wanted to have a PR ready by Monday night but didn't have enough time. I've been using the tiresx library. It wasn't to hard to get a simple example working but as I tried to add analyzers I ran into issues. Not huge issues but it did slow me down and there almost no documentation on the library. If time is allowed I almost think it's worth writing a module to handle instead of using a library. The API is well documented and since it's being used in one controller it should be pretty easy to do. Let me know your thoughts.

Also I did my development outside of the API code. I need a better understanding of how elastic search works within docker. I noticed in the documentation that the default port used by elasticsearch is blocked.

Thanks
Paul

[joshsmith]

@paulsullivanjr sounds good! Let me know if you want any help on getting the Docker side up and running.

If you think calling out to Elasticsearch is easier via a module, then I'm happy to take that approach. It seems reasonable to me, honestly.

[paulsullivanjr]

@joshsmith Sounds good. I'll get started on the development. I'll touch base with you about the docker stuff when I'm ready for it. Thanks.

[joshsmith]

Okay thanks. I'll be around if you need me.