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https://github.com/danielberkompas/elasticsearch-elixir

No-nonsense Elasticsearch library for Elixir
https://github.com/danielberkompas/elasticsearch-elixir

elasticsearch elixir

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No-nonsense Elasticsearch library for Elixir

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README 

        
# Elasticsearch



[![Hex.pm](https://img.shields.io/hexpm/v/elasticsearch.svg)](https://hex.pm/packages/elasticsearch)

[![Build Status](https://danielberkompas.semaphoreci.com/badges/elasticsearch-elixir/branches/master.svg?style=shields)](https://danielberkompas.semaphoreci.com/projects/elasticsearch-elixir)

[![Coverage Status](https://coveralls.io/repos/github/danielberkompas/elasticsearch-elixir/badge.svg?branch=master)](https://coveralls.io/github/danielberkompas/elasticsearch-elixir?branch=master)



A simple, no-nonsense Elasticsearch library for Elixir. Highlights include:



- **No DSLs.** Interact directly with the `Elasticsearch` JSON API.

- **Zero-downtime index (re)building.** Via `Mix.Tasks.Elasticsearch.Build` task.

- **Dev Tools**. Helpers for running Elasticsearch as part of your supervision

  tree during development.



## Installation



Add `elasticsearch` to your list of dependencies in `mix.exs`:



```elixir

def deps do

  [

    {:elasticsearch, "~> 1.0.0"}

  ]

end

```



Then, create an `Elasticsearch.Cluster` in your application:



```elixir

defmodule MyApp.ElasticsearchCluster do

  use Elasticsearch.Cluster, otp_app: :my_app

end

```



Once you have created your cluster, add it to your application's supervision tree:



```elixir

children = [

  MyApp.ElasticsearchCluster

]

```



Finally, you can issue requests to Elasticsearch using it.



```elixir

Elasticsearch.get(MyApp.ElasticsearchCluster, "/_cat/health")

```



## Configuration



See the annotated example configuration below.



```elixir

config :my_app, MyApp.ElasticsearchCluster,

  # The URL where Elasticsearch is hosted on your system

  url: "http://localhost:9200",



  # If your Elasticsearch cluster uses HTTP basic authentication,

  # specify the username and password here:

  username: "username",

  password: "password",



  # If you want to mock the responses of the Elasticsearch JSON API

  # for testing or other purposes, you can inject a different module

  # here. It must implement the Elasticsearch.API behaviour.

  api: Elasticsearch.API.HTTP,



  # Customize the library used for JSON encoding/decoding.

  json_library: Poison, # or Jason



  # You should configure each index which you maintain in Elasticsearch here.

  # This configuration will be read by the `mix elasticsearch.build` task,

  # described below.

  indexes: %{

    # This is the base name of the Elasticsearch index. Each index will be

    # built with a timestamp included in the name, like "posts-5902341238".

    # It will then be aliased to "posts" for easy querying.

    posts: %{

      # This file describes the mappings and settings for your index. It will

      # be posted as-is to Elasticsearch when you create your index, and

      # therefore allows all the settings you could post directly.

      settings: "priv/elasticsearch/posts.json",



      # This store module must implement a store behaviour. It will be used to

      # fetch data for each source in each indexes' `sources` list, below:

      store: MyApp.ElasticsearchStore,



      # This is the list of data sources that should be used to populate this

      # index. The `:store` module above will be passed each one of these

      # sources for fetching.

      #

      # Each piece of data that is returned by the store must implement the

      # Elasticsearch.Document protocol.

      sources: [MyApp.Post],



      # When indexing data using the `mix elasticsearch.build` task,

      # control the data ingestion rate by raising or lowering the number

      # of items to send in each bulk request.

      bulk_page_size: 5000,



      # Likewise, wait a given period between posting pages to give

      # Elasticsearch time to catch up.

      bulk_wait_interval: 15_000, # 15 seconds



      # By default bulk indexing uses the "create" action. To allow existing

      # documents to be replaced, use the "index" action instead.

      bulk_action: "create"

    }

  }

```



#### Specifying HTTPoison Options



```elixir

config :my_app, MyApp.ElasticsearchCluster,

  default_options: [

    timeout: 5_000,

    recv_timeout: 5_000,

    hackney: [pool: :pool_name]

  ]

```



## Protocols and Behaviours



#### Elasticsearch.Store



Your app must provide a `Store` module, which will fetch data to upload to

Elasticsearch. This module must implement the `Elasticsearch.Store`

behaviour.



The example below uses `Ecto`, but you can implement the behaviour on top

of any persistence layer.



```elixir

defmodule MyApp.ElasticsearchStore do

  @behaviour Elasticsearch.Store



  import Ecto.Query



  alias MyApp.Repo



  @impl true

  def stream(schema) do

    Repo.stream(schema)

  end



  @impl true

  def transaction(fun) do

    {:ok, result} = Repo.transaction(fun, timeout: :infinity)

    result

  end

end

```



#### Elasticsearch.Document



Each result returned by your store must implement the `Elasticsearch.Document`

protocol.



```elixir

defimpl Elasticsearch.Document, for: MyApp.Post do

  def id(post), do: post.id

  def routing(_), do: false

  def encode(post) do

    %{

      title: post.title,

      author: post.author

    }

  end

end

```



#### Elasticsearch.API



You can plug in a different module to make API requests, as long as it

implements the `Elasticsearch.API` behaviour.



This can be used in test mode, for example:



```elixir

# config/test.exs

config :my_app, MyApp.ElasticsearchCluster,

  api: MyApp.ElasticsearchMock

```



Your mock can then stub requests and responses from Elasticsearch.



```elixir

defmodule MyApp.ElasticsearchMock do

  @behaviour Elasticsearch.API



  @impl true

  def request(_config, :get, "/posts/1", _data, _opts) do

    {:ok, %HTTPoison.Response{

      status_code: 404,

      body: %{

        "status" => "not_found"

      }

    }}

  end

end

```



#### Elasticsearch.API.AWS



As AWS does not provide credentials' based http authentication, you can use the `Elasticsearch.API.AWS` module if you want to use AWS Elasticsearch Service with AWS Signature V4 signed HTTP connections.



To use this, just add `sigaws` to your dependencies and add this to your configuration:



```elixir

# Add to deps 

def deps do

  [          

    # ...

    {:sigaws, ">= 0.0.0"}

  ]

end



# config/prod.exs

config :my_app, MyApp.ElasticsearchCluster,

  api: Elasticsearch.API.AWS,

  default_options: [

    aws: [

      region: "us-east-1",

      service: "es",

      access_key: "aws_access_key_id",

      secret: "aws_secret_access_key"

    ]

  ]

```



## Indexing



#### Bulk



Use the `mix elasticsearch.build` task to build indexes using a zero-downtime,

hot-swap technique with Elasticsearch aliases.



```bash

# This will read the `indexes[posts]` configuration seen above, to build

# an index, `posts-123123123`, which will then be aliased to `posts`.

$ mix elasticsearch.build posts --cluster MyApp.ElasticsearchCluster

```



See the docs on `Mix.Tasks.Elasticsearch.Build` and `Elasticsearch.Index`

for more details.



#### Individual Documents



Use `Elasticsearch.put_document/3` to upload a document to a particular index.



```elixir

# MyApp.Post must implement Elasticsearch.Document

Elasticsearch.put_document(MyApp.ElasticsearchCluster, %MyApp.Post{}, "index-name")

```



To remove documents, use `Elasticsearch.delete_document/3`:



```elixir

Elasticsearch.delete_document(MyApp.ElasticsearchCluster, %MyApp.Post{}, "index-name")

```



## Querying



You can query Elasticsearch the `post/3` function:



```elixir

# Raw query

Elasticsearch.post(MyApp.ElasticsearchCluster, "/posts/_doc/_search", '{"query": {"match_all": {}}}')



# Using a map

Elasticsearch.post(MyApp.ElasticsearchCluster, "/posts/_doc/_search", %{"query" => %{"match_all" => %{}}})

```



See the official Elasticsearch [documentation](https://www.elastic.co/guide/en/elasticsearch/reference/6.x/index.html)

for how to write queries.



## Dev Tools



This package provides two utilities for developing with Elasticsearch:



- `mix elasticsearch.install`: A mix task to install Elasticsearch and Kibana

  to a folder of your choosing.



- `Elasticsearch.Executable`. Use this to start and stop Elasticsearch as part

  of your supervision tree.



  ```elixir

  children = [

    worker(Elasticsearch.Executable, [

      "Elasticsearch",

      "./vendor/elasticsearch/bin/elasticsearch", # assuming elasticsearch is in your vendor/ dir

      9200

    ], id: :elasticsearch),

    worker(Elasticsearch.Executable, [

      "Kibana",

      "./vendor/kibana/bin/kibana", # assuming kibana is in your vendor/ dir

      5601

    ], id: :kibana)

  ]

  ```



## Elasticsearch 5.x Support



As of version `0.3.0` of this client library, multiple document types are not

supported, because support for these was removed in Elasticsearch 6.x. You

can still use this library with Elasticsearch 5.x, but you must design your

indexes in the Elasticsearch 6.x style.



Read more about this in Elasticsearch's guide, ["Removal of Mapping

Types"](https://www.elastic.co/guide/en/elasticsearch/reference/6.2/removal-of-types.html).



## Documentation



[Hex Documentation](https://hexdocs.pm/elasticsearch)



Run `mix docs` to generate local documentation.



## Contributing



To contribute code to this project, you'll need to:



1. Fork the repo

2. Clone your fork

3. Run `bin/setup`

4. Create a branch

5. Commit your changes

6. Open a PR