A trait to ease the process of migrating to a new elastic search index

MigratesElasticSearchIndices.php

<?php

namespace Sparky\Domain;

use Carbon\Carbon;
use Sparky\ElasticSearchModel;

trait MigratesElasticSearchIndices
{
    /**
     * Migrate a new version of an index.
     *
     * @param  \Sparky\ElasticSearchModel  $model
     * @param  int  $version
     * @param  array  $properties
     */
    public function migrateIndex(ElasticSearchModel $model, int $version, array $properties)
    {
        $client = app('elasticsearch');

        $alias = $model->getElasticIndex();
        $type = $model->getElasticType();

        $index = $alias.'-'.$version;

        $currentIndex = $alias.'-'.$version-1;

        $description = [
            'mappings' => [
                $type => [
                    'properties' => $properties,
                ],
            ],
        ];

        $client->indices()->create($description);

        // Reindex the existing data

        $timestamp = null;

        while (true) {

            if ($timestamp) {
                $query = [
                    'filtered' => [
                        'query' => [
                            'match_all' => [],
                        ],
                        'filter' => [
                            'range' => [
                                'created_at' => [
                                    'gte' => $timestamp,
                                ],
                            ],
                        ],
                    ],
                ];
            } else {
                $query = ['match_all' => []];
            }
            $timestamp = Carbon::now()->format('Y-m-d H:i:s');

            $search = $client->search([
                'search_type' => 'scan',
                'scroll'      => '1m',
                'size'        => 1000,
                'index'       => $currentIndex,
                'sort'        => ['_doc'],
                'body'        => [
                    'query' => [
                        $query
                    ]
                ]
            ]);

            $scrollId = $search['_scroll_id'];

            while (true) {
                $response = $client->scroll([
                    'scroll_id' => $scrollId,
                    'scroll' => '1m',
                ]);

                if (! count($response['hits']['hits'])) {
                    break;
                }

                $scrollId = $response['_scroll_id'];

                $results = array_map(function ($result) {
                    return ['create' => $result['_source']];
                }, $response['hits']['hits']);


                $client->bulk([
                    'index' => $index,
                    'type'  => $type,
                    'body'  => $results,
                ]);
            }

            if ($scrollId == $search['_scroll_id']) {
                break;
            }
        }



        $client->indices()->deleteAlias([
            'index' => $currentIndex,
            'name'  => $alias,
        ]);

        $client->indices()->putAlias([
            'index' => $index,
            'name'  => $alias,
        ]);
    }
}