Accessing an Elasticsearch Cluster Using PHP

Prerequisites

• The target Elasticsearch cluster is available.
• The server that runs the PHP code can communicate with the Elasticsearch cluster.
• Depending on the network configuration method used, obtain the cluster access address. For details, see Network Configuration.
• The Elasticsearch PHP client has been installed on the server. For details, see Elasticsearch PHP Client.

  In this document, the installed PHP version is 8.0.30, the Composer version is 2.9.2, the Elasticsearch PHP client version is 7.17.2, and the connected Elasticsearch cluster version is 7.10.2.

Installing the PHP Client Library

Install the PHP client library on the server that runs the PHP code.

yum install -y php

Accessing a Cluster

The sample code varies depending on the security mode settings of the target Elasticsearch cluster. Select the right reference document based on your service scenario.

Connecting to a Non-Security Mode Cluster with the Elasticsearch PHP Client

Use the Elasticsearch PHP client to connect to a non-security mode Elasticsearch cluster, and obtain the cluster health status.

The following is an example of the code for creating a client instance using the cluster connection information:

<?php
require 'vendor/autoload.php';

use Elasticsearch\ClientBuilder;

class ElasticsearchClient
{
    private $client;

    public function __construct($config)
    {
        $this->client = ClientBuilder::create()
            ->setHosts($config['hosts'])
            ->setConnectionPool('\Elasticsearch\ConnectionPool\SimpleConnectionPool', [])
            ->setRetries($config['retries'] ?? 3)
            ->setConnectionParams([
                'client' => [
                    'timeout' => 10,
                    'connect_timeout' => 5
                ]
            ])
            ->build();
    }

    public function getClusterHealth()
    {
        return $this->client->cluster()->health();
    }
}

$config = [
    'hosts' => [
        'http://IP:9200',
        'http://IP:9200'
    ],
    'retries' => 2
];

$es = new ElasticsearchClient($config);
print_r($es->getClusterHealth());
?>

The code obtains the cluster health status. If a result similar to the following is returned, the cluster is connected.

1
2
3
4
5
6

Array
(
    [cluster_name] => css-xxxx-php
    [status] => green
    ...
)

Connecting to a Security-Mode+HTTP Cluster with the Elasticsearch PHP Client

Use the Elasticsearch PHP client to connect to a security-mode Elasticsearch cluster that uses HTTP, and obtain the cluster health status.

The following is an example of the code for creating a client instance using the cluster connection information:

<?php
require 'vendor/autoload.php';

use Elasticsearch\ClientBuilder;

class ElasticsearchClient
{
    private $client;

    public function __construct($config)
    {
        $this->client = ClientBuilder::create()
            ->setHosts($config['hosts'])
            ->setBasicAuthentication($config['username'], $config['password'])
            ->setConnectionPool('\Elasticsearch\ConnectionPool\SimpleConnectionPool', [])
            ->setRetries($config['retries'] ?? 3)
            ->setConnectionParams([
                'client' => [
                    'timeout' => 10,
                    'connect_timeout' => 5
                ]
            ])
            ->build();
    }

    public function getClusterHealth()
    {
        return $this->client->cluster()->health();
    }
}

$config = [
    'hosts' => [
        'http://IP:9200',
        'http://IP:9200'
    ],
    'username' => 'USERNAME',
    'password' => 'PASSWORD',
    'retries' => 2
];

$es = new ElasticsearchClient($config);
print_r($es->getClusterHealth());
?>

The code obtains the cluster health status. If a result similar to the following is returned, the cluster is connected.

1
2
3
4
5
6

Array
(
    [cluster_name] => css-xxxx-php
    [status] => green
    ...
)

Connecting to a Security-Mode+HTTPS Cluster with the Elasticsearch PHP Client (Without a Certificate)

Use the Elasticsearch PHP client to connect to a security-mode Elasticsearch cluster that uses HTTPS without loading a security certificate, and obtain the cluster health status.

The following is an example of the code for creating a client instance using the cluster connection information:

<?php
require 'vendor/autoload.php';

use Elasticsearch\ClientBuilder;

class ElasticsearchClient
{
    private $client;

    public function __construct($config)
    {
        $this->client = ClientBuilder::create()
            ->setHosts($config['hosts'])
            ->setBasicAuthentication($config['username'], $config['password'])
            ->setSSLVerification($config['ssl_verify'] ?? false)
            ->setConnectionPool('\Elasticsearch\ConnectionPool\SimpleConnectionPool', [])
            ->setRetries($config['retries'] ?? 3)
            ->setConnectionParams([
                'client' => [
                    'timeout' => 10,
                    'connect_timeout' => 5
                ]
            ])
            ->build();
    }

    public function getClusterHealth()
    {
        return $this->client->cluster()->health();
    }
}

$config = [
    'hosts' => [
        'https://IP:9200',
        'https://IP:9200'
    ],
    'username' => 'USERNAME',
    'password' => 'PASSWORD',
    'ssl_verify' => false,
    'retries' => 2
];

$es = new ElasticsearchClient($config);
print_r($es->getClusterHealth());
?>

The code obtains the cluster health status. If a result similar to the following is returned, the cluster is connected.

1
2
3
4
5
6

Array
(
    [cluster_name] => css-xxxx-php
    [status] => green
    ...
)

Connecting to a Security-Mode+HTTPS Cluster with the Elasticsearch PHP Client (With a Certificate)

Use the Elasticsearch PHP client to connect to a security-mode Elasticsearch cluster that uses HTTPS while loading a security certificate, and obtain the cluster health status.

For how to obtain and upload a security certificate, see Obtaining and Uploading a Security Certificate.

The following is an example of the code for creating a client instance using the cluster connection information:

<?php
require 'vendor/autoload.php';

use Elasticsearch\ClientBuilder;

class ElasticsearchClient
{
    private $client;

    public function __construct($config)
    {
        $this->client = ClientBuilder::create()
            ->setHosts($config['hosts'])
            ->setBasicAuthentication($config['username'], $config['password'])
            ->setSSLVerification($config['ssl_verify'] ?? true)
            ->setConnectionPool('\Elasticsearch\ConnectionPool\SimpleConnectionPool', [])
            ->setRetries($config['retries'] ?? 3)
            ->setConnectionParams([
                'client' => [
                    'timeout' => 10,
                    'connect_timeout' => 5
                ]
            ])
            ->build();
    }

    public function getClusterHealth()
    {
        return $this->client->cluster()->health();
    }
}

$config = [
    'hosts' => [
        'https://IP:9200',
        'https://IP:9200'
    ],
    'username' => 'USERNAME',
    'password' => 'PASSWORD',
    'ssl_verify' => true,
    'retries' => 2
];

$es = new ElasticsearchClient($config);
print_r($es->getClusterHealth());
?>

The code obtains the cluster health status. If a result similar to the following is returned, the cluster is connected.

1
2
3
4
5
6

Array
(
    [cluster_name] => css-xxxx-php
    [status] => green
    ...
)

Obtaining and Uploading a Security Certificate

To access a security-mode Elasticsearch cluster that uses HTTPS, perform the following steps to obtain the security certificate if it is required, and upload it to the client.

1. Obtain the security certificate CloudSearchService.cer.
   1. Log in to the CSS management console.
   2. In the navigation pane on the left, choose Clusters > Elasticsearch.
   3. In the cluster list, click the name of the target cluster. The cluster information page is displayed.
   4. Click the Overview tab. In the Network Information area, click Download Certificate below HTTPS Access.
      Figure 1 Downloading a security certificate
      
2. Upload the downloaded certificate to the server.
3. Find the PHP installation directory on the server and modify the php.ini file.

   curl.cainfo="/tmp/CloudSearchService" // Replace it with the full absolute path of the security certificate.