Creating index with alias - amazon-web-services

Question

Sorry for the rudimentary question．I'm developing PHP small test class that manipulates AWS Elasticsearch Service.
<?php
namespace MyCompany\Aws;
use Elasticsearch\ClientBuilder;
class ElasticsearchApi {
private $client;
function __construct(string $hosts='', string $username='', string $password=''){
... //configure $this->client
}
/**
* Create index
* #param string $index
* #param array $body
* #return bool
*/
public function createIndex(string $index, array $body = []):bool{
$request = array(
'index' => $index,
'body' => $body
);
$ret = $this->client->indices()->create($request);
return $ret['acknowledged'];
}
}
And call createIndex function specifying alias as described at:
https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-create-index.html
https://www.elastic.co/guide/en/elasticsearch/reference/current/indices-aliases.html
<?php
require 'vendor/autoload.php';
use MyCompany\Aws\ElasticsearchApi as ES;
$es = new ES();
$body = array('aliases'=>array(
'actions'=>array(
'add'=>array(
'alias'=>'sample-alias',
'index'=>'test-index'
)
)
));
$ret = $es->createIndex('test-index',$body);
var_dump($ret);
This operation normally ends:
PS D:\My_Documents\Proj\Elasticsearch\index-gen> php es-lib-test.php
bool(true)
PS D:\My_Documents\Proj\Elasticsearch\index-gen>
However the generated index does not seem to have alias.
What is wrong with createIndex parameter? I'm using version 7.8 of Elasticsearch on AWS.
Addendum
Based on the #Val 's suggestion, I changed the code as follows:
$body = array(
'aliases'=>array(
'sample-alias'=>array()
)
);
$ret = $es->createIndex('test-index',$body);
var_dump($ret);
However I got the following exception. Are there any mistakes?
PS D:\My_Documents\Proj\Elasticsearch\index-gen> php es-lib-test.php
PHP Fatal error: Uncaught Elasticsearch\Common\Exceptions\BadRequest400Exception: {"error":{"root_cause":[{"type":"illegal_argument_exception","reason":"No alias is specified"}],"type":"illegal_argument_exception","reason":"No alias is specified"},"status":400} in D:\My_Documents\Proj\Elasticsearch\index-gen\vendor\elasticsearch\elasticsearch\src\Elasticsearch\Connections\Connection.php:641
Stack trace:
#0 D:\My_Documents\Proj\Elasticsearch\index-gen\vendor\elasticsearch\elasticsearch\src\Elasticsearch\Connections\Connection.php(328): Elasticsearch\Connections\Connection->process4xxError(Array, Array, Array)
#2 D:\My_Documents\Proj\Elasticsearch\index-gen\vendor\ezimuel\ringphp\src\Future\CompletedFutureValue.php(55): React\Promise\FulfilledPromise->then(Object(Closure), NULL, NULL)
#3 D:\My_Documents\Proj\Elasticsearch\index-gen\vendor\ezimuel\ring in D:\My_Documents\Proj\Elasticsearch\index-gen\vendor\elasticsearch\elasticsearch\src\Elasticsearch\Connections\Connection.php on line 641

Answer 1

Your body should simply look like this:
$body = array('aliases' => array('sample-alias' => array()));
The syntax you're using is for the _aliases endpoint not for the index creation one.