Query Elasticsearch Data Using the OData SDK for PHP

The CData API Server, when paired with the ADO.NET Provider for Elasticsearch, exposes Elasticsearch data (or data from any of 200+ other ADO.NET Providers) as Web services. You can follow the procedure below to work with Elasticsearch data as PHP objects.

Getting Started

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Set Up the API Server

Follow the steps below to begin producing secure Elasticsearch OData services:

Deploy

The API Server runs on your own server. On Windows, you can deploy using the stand-alone server or IIS. On a Java servlet container, drop in the API Server WAR file. See the help documentation for more information and how-tos.

The API Server is also easy to deploy on Microsoft Azure, Amazon EC2, and Heroku.

Connect to Elasticsearch

After you deploy the API Server and the ADO.NET Provider for Elasticsearch, provide authentication values and other connection properties needed to connect to Elasticsearch by clicking Settings -> Connections and adding a new connection in the API Server administration console.

Set the Server and Port connection properties to connect. To authenticate, set the User and Password properties, PKI (public key infrastructure) properties, or both. To use PKI, set the SSLClientCert, SSLClientCertType, SSLClientCertSubject, and SSLClientCertPassword properties.

The data provider uses X-Pack Security for TLS/SSL and authentication. To connect over TLS/SSL, prefix the Server value with 'https://'. Note: TLS/SSL and client authentication must be enabled on X-Pack to use PKI.

Once the data provider is connected, X-Pack will then perform user authentication and grant role permissions based on the realms you have configured.

You can then choose the Elasticsearch entities you want to allow the API Server access to by clicking Settings -> Resources.

Additionally, configure the API Server for compatibility with the OData SDK for PHP: Click Server -> Settings and in the OData section set Default Version to 2.0.

Authorize API Server Users

After determining the OData services you want to produce, authorize users by clicking Settings -> Users. The API Server uses authtoken-based authentication and supports the major authentication schemes. You can authenticate as well as encrypt connections with SSL. Access can also be restricted based on IP address; by default, only connections from the local machine are allowed.

For simplicity, we will authenticate to the API Server by setting the authtoken in the URL. This is not enabled by default; you will need to add the following lines to the API Server configuration file, settings.cfg.

The settings.cfg file is located in the data directory. In the .NET edition, the data directory is the app_data folder under the www folder. In the Java edition, the data directory's location depends on the operation system:

• Windows: C:\ProgramData\CData\Elasticsearch\
• Unix or Mac OS X: ~/cdata/Elasticsearch/

Work with Elasticsearch Entities as PHP Objects

Follow the steps below to use the ODataPHP SDK to create a proxy class that will connect to the Web services exposed by the API Server.

1. Pass the URL to a command like the one below:

   php C:\PHPLib\ODataphp\PHPDataSvcUtil.php /uri=https://your-server:8032/api.rsc/@your-authtoken/ /out=C:\PHPLib\ODataphp\ElasticsearchEntities.php

   The preceding command defines classes from the metadata returned in the response from the OData endpoint, then outputs the class definitions to the specified folder.

   Both the API Server and the OData SDK for PHP support forms and Windows authentication. The API Server uses authtokens to authenticate users authorized to access the OData endpoint. You can supply authtokens in HTTP Basic authentication or append them to the OData URL.

   You can configure authorized users in the Settings -> Users section of the API Server administration console.

2. You can now start accessing Elasticsearch data using an object-oriented interface in PHP. The code below creates a record of the Orders table and then retrieves the live data, showing the newly created record.

   require_once 'ElasticsearchEntities.php'; try{ $svc = new CData(); $orders = new Orders(); $orders->ShipCity = 'New York'; $svc->AddToOrders($orders); $svc->SetSaveChangesOptions(SaveChangesOptions::None); $svc->SaveChanges(); $response = $svc->orders()->Execute(); foreach($response->Result as $orders) echo $orders->OrderName."
"; } catch (Exception $e) { //catch errors from the API Server echo $e->getError(), "\n"; }