# Elasticsearch

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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`:

def deps do
    {:elasticsearch, "~> 1.0.0"}

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

defmodule MyApp.ElasticsearchCluster do
  use Elasticsearch.Cluster, otp_app: :my_app

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

children = [

Finally, you can issue requests to Elasticsearch using it.

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

## Configuration

See the annotated example configuration below.

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` 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` 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

#### Specifying HTTPoison Options

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`

The example below uses `Ecto`, but you can implement the behaviour on top
of any persistence layer.

defmodule MyApp.ElasticsearchStore do
  @behaviour Elasticsearch.Store

  import Ecto.Query

  alias MyApp.Repo

  @impl true
  def stream(schema) do

  @impl true
  def transaction(fun) do
    {:ok, result} = Repo.transaction(fun, timeout: :infinity)

#### Elasticsearch.Document

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

defimpl Elasticsearch.Document, for: MyApp.Post do
  def id(post), do:
  def routing(_), do: false
  def encode(post) do
      title: post.title,

#### 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:

# config/test.exs
config :my_app, MyApp.ElasticsearchCluster,
  api: MyApp.ElasticsearchMock

Your mock can then stub requests and responses from Elasticsearch.

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"

#### 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:

# Add to deps 
def deps do
    # ...
    {:sigaws, ">= 0.0.0"}

# 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` task to build indexes using a zero-downtime,
hot-swap technique with Elasticsearch aliases.

# This will read the `indexes[posts]` configuration seen above, to build
# an index, `posts-123123123`, which will then be aliased to `posts`.
$ mix 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.

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

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

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

## Querying

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

# Raw query, "/posts/_doc/_search", '{"query": {"match_all": {}}}')

# Using a map, "/posts/_doc/_search", %{"query" => %{"match_all" => %{}}})

See the official Elasticsearch [documentation](
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.

  children = [
    worker(Elasticsearch.Executable, [
      "./vendor/elasticsearch/bin/elasticsearch", # assuming elasticsearch is in your vendor/ dir
    ], id: :elasticsearch),
    worker(Elasticsearch.Executable, [
      "./vendor/kibana/bin/kibana", # assuming kibana is in your vendor/ dir
    ], 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

## Documentation

[Hex Documentation](

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