ZIO Elasticsearch

Overview

ZIO Elasticsearch is a type-safe and streaming-friendly ZIO native Elasticsearch client.

The library depends on sttp as an HTTP client for executing requests, and other ZIO libraries such as ZIO Schema and ZIO Prelude.

The following versions are supported:

• Scala: 2.12, 2.13 and 3
• ZIO: 2
• Elasticsearch: 7
• JVM 11+

Installation

To use ZIO Elasticsearch in your project, add the following line to your build.sbt file:

libraryDependencies += "io.lambdaworks" %% "zio-elasticsearch" % "0.1.0"

Usage

In order to execute an Elasticsearch request we can rely on the Elasticsearch layer which offers an execute method accepting an ElasticRequest. In order to build the Elasticsearch layer we need to provide the following layers:

• ElasticExecutor: if you provide ElasticExecutor.local, it will run on localhost:9200. Otherwise, if you want to use ElasticExecutor.live, you must also provide ElasticConfig.
• HttpClientZioBackend

import sttp.client3.httpclient.zio.HttpClientZioBackend
import zio.elasticsearch._
import zio._

object ZIOElasticsearchExample extends ZIOAppDefault {
  val indexName = IndexName("index")
  val result: RIO[Elasticsearch, CreationOutcome] = 
    Elasticsearch.execute(ElasticRequest.createIndex(indexName))

  override def run =
    result.provide(
      ElasticExecutor.local,
      Elasticsearch.layer,
      HttpClientZioBackend.layer()
    )
}

Type-safety with ZIO Prelude's Newtype

The library uses ZIO Prelude's Newtype for IndexName, DocumentId and Routing in order to preserve type-safety.

val indexName: IndexName   = IndexName("index")
val documentId: DocumentId = DocumentId("documentId")

Usage of ZIO Schema and its accessors for type-safety

To provide type-safety in your Elasticsearch requests, ZIO Elasticsearch uses ZIO Schema. Here is an example of creating a schema for the custom type User and using an implicit schema to create accessors that result in type-safe requests.

final case class Address(street: String, number: Int)

object Address {
  implicit val schema: Schema.CaseClass2[String, Int, Address] =
    DeriveSchema.gen[Address]

  val (street, number) = schema.makeAccessors(FieldAccessorBuilder)
}

final case class User(id: Int, address: Address)

object User {
  implicit val schema: Schema.CaseClass2[String, Address, User] =
    DeriveSchema.gen[User]

  val (id, address) = schema.makeAccessors(FieldAccessorBuilder)
}

val query: BoolQuery[User] =
  ElasticQuery
    .must(ElasticQuery.range(User.id).gte(7).lt(10))
    .should(ElasticQuery.startsWith(User.address / Address.street, "ZIO"))

val aggregation: TermsAggregation =
  ElasticAggregation
    .termsAggregation("termsAgg", User.address / Address.street)

val request: SearchAndAggregateRequest =
  ElasticRequest
    .search(IndexName("index"), query)
    .aggregate(aggregation)

val result: RIO[Elasticsearch, SearchResult] = Elasticsearch.execute(request)

Fluent API

ZIO Elastic requests and queries offer a fluent API, allowing us to provide optional parameters in chained method calls for each request or query. For example, if we wanted to add routing and refresh parameters to a deleteById request:

ElasticRequest.deleteById(IndexName("index"), DocumentId("documentId")).routing(Routing("routing")).refreshTrue

Creating complex queries can be created in the following manner:

ElasticQuery.must(ElasticQuery.range("version").gte(7).lt(10)).should(ElasticQuery.startsWith("name", "ZIO"))

If we want to specify lower and upper bounds for a range query, we can do the following:

ElasticQuery.range(User.age).gte(18).lt(100)

Bulkable

ZIO Elastic requests like Create, CreateOrUpdate, CreateWithId, and DeleteById are bulkable requests. For bulkable requests, you can use bulk API that accepts request types that inherit the Bulkable trait.

ElasticRequest.bulk(
  ElasticRequest.create[User](indexName, User(1, "John Doe")),
  ElasticRequest.create[User](indexName, DocumentId("documentId2"), User(2, "Jane Doe")),
  ElasticRequest.upsert[User](indexName, DocumentId("documentId3"), User(3, "Richard Roe")),
  ElasticRequest.deleteById(indexName, DocumentId("documentId2"))
)

Streaming

ZIO Elasticsearch is a streaming-friendly library, and it provides specific APIs for creating ZIO streams. When using the stream API, the result will be an Item, which is a case class that contains only one field, raw, that represents your response as raw JSON. Additionally, it is important to note that you can use StreamConfig to customize your settings when creating a stream. If you don't use StreamConfig, the default settings (StreamConfig.Default) will be used.

val request: SearchRequest =
  ElasticRequest.search(IndexName("index"), ElasticQuery.range(User.id).gte(5))

val defaultStream: ZStream[Elasticsearch, Throwable, Item] =
  Elasticsearch.stream(request)

val scrollStream: ZStream[Elasticsearch, Throwable, Item]  =
  Elasticsearch.stream(request, StreamConfig.Scroll)

val searchAfterStream: ZStream[Elasticsearch, Throwable, User] =
  Elasticsearch.streamAs[User](request, StreamConfig.SearchAfter)

Example

For a full-fledged example using this library, you can check out the example module, which contains an application with both a description and instructions on how to run it.

Documentation

Learn more on the ZIO Elasticsearch homepage!

Contributing

For the general guidelines, see ZIO Elasticsearch contributor's guide.

Code of Conduct

See the Code of Conduct.

License

License