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.
Add elasticsearch
to your list of dependencies in mix.exs
:
def deps do
[
{:elasticsearch, "~> 1.0.0"}
]
end
Then, create an Elasticsearch.Cluster
in your application:
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:
children = [
MyApp.ElasticsearchCluster
]
Finally, you can issue requests to Elasticsearch using it.
Elasticsearch.get(MyApp.ElasticsearchCluster, "/_cat/health")
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 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"
}
}
config :my_app, MyApp.ElasticsearchCluster,
default_options: [
timeout: 5_000,
recv_timeout: 5_000,
hackney: [pool: :pool_name]
]
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.
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
Each result returned by your store must implement the Elasticsearch.Document
protocol.
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
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"
}
}}
end
end
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"}
]
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"
]
]
Use the mix elasticsearch.build
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 elasticsearch.build posts --cluster MyApp.ElasticsearchCluster
See the docs on Mix.Tasks.Elasticsearch.Build
and Elasticsearch.Index
for more details.
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")
You can query Elasticsearch the post/3
function:
# 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 for how to write queries.
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, [ "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) ]
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".
Run mix docs
to generate local documentation.
To contribute code to this project, you'll need to:
- Fork the repo
- Clone your fork
- Run
bin/setup
- Create a branch
- Commit your changes
- Open a PR