Lumen Elasticsearch

Simple wrapper of Elasticsearch-PHP for the Lumen PHP framework.

Version support

Requirements

• 3.x requires PHP 7.1 or newer
• 2.x requires PHP 5.6 or newer

Usage

Installation

Run the following command to install the package through Composer:

composer require nordsoftware/lumen-elasticsearch

Copy the configuration template in config/elasticsearch.php to your application's config directory and modify it to suit your needs.

Add the following line to bootstrap/app.php:

$app->register(Nord\Lumen\Elasticsearch\ElasticsearchServiceProvider::class);

You can now get the service instance using app(ElasticsearchServiceContract::class) or inject the ElasticsearchServiceContract where needed.

Configuring your indices

You can create and delete indices using the provided console commands. Start by adding the commands to your console kernel:

protected $commands = [
	...
	CreateCommand::class,
	DeleteCommand::class,
];

To create an index you need a configuration file that describes how the index should look. To create an index called my-index, create a file named my-index.php in the config/elasticsearch directory (create the directory if it doesn't exist) with the following contents:

<?php

return [
    'index' => 'my-index',
    'body' => [
        'mappings' => [
            'my-model' => [
                'properties' => [
                    'id' => ['type' => 'string', 'index' => 'not_analyzed'],
                    'name' => ['type' => 'string'],
                ],
            ],
        ],
        'settings' => [
            'analysis' => [
                'filter' => [
                    'finnish_stop' => [
                        'type' => 'stop',
                        'stopwords' => '_finnish_',
                    ],
                    'finnish_stemmer' => [
                        'type' => 'stemmer',
                        'language' => 'finnish',
                    ],
                ],
                'analyzer' => [
                    'finnish' => [
                        'tokenizer' => 'standard',
                        'filter' => [
                            'lowercase',
                            'finnish_stop',
                            'finnish_stemmer',
                        ],
                    ],
                ],
            ],
        ],
    ],
];

Please refer to the official Elasticsearch documentation for more information on how to define indices.

Now that you have a configuration file for your index, create it by running php artisan elastic:index:create config/elasticsearch/my-index.php.

To delete the index, run php artisan elastic:index:delete my-index.

Indexing your data

To index data into your newly created indices you need to create a new console command that extends Nord\Lumen\Elasticsearch\Console\IndexCommand, then register that command in your console kernel. A sample implementation can look like this:

<?php

use Nord\Lumen\Elasticsearch\Console\IndexCommand;

class IndexPersonsCommand extends IndexCommand
{

    protected $signature = 'app:index:persons';

    protected $description = 'Indexes all persons into the search index';

    public function getData()
    {
        return [
            new Person('Joe'),
            new Person('Jane'),
        ];
    }

    public function getIndex()
    {
        return 'persons';
    }

    public function getType()
    {
        return 'person';
    }

    public function getItemBody($item)
    {
        // Item is an instance of Person in this case
        return $item->getName();
    }

    public function getItemId($item)
    {
        // Item is an instance of Person in this case
        return $item->getId();
    }

    public function getItemParent($item)
    {
        // Return null if your objects don't have any parent/child relationship
        return $item->getParent();
    }

}

Now, run php artisan app:index:persons to index the data. You can now create additional commands for your other data types that need to be indexed.

In addition to IndexCommand there is an AbstractMultiIndexCommand that can be used if you need to index the same data into multiple indices. This can be useful if you're migrating Elasticsearch 5.x indices to Elasticsearch 6.x, which doesn't support indices with multiple different document types.

Indexing single items

The console commands are useful when you want to index all items of a particular type, e.g. all persons in your database. However, if you update a single person you probably want to reindex just that person.

Here's an example:

$service = app(ElasticsearchServiceContract::class);

$service->index([
	'index' => 'persons',
	'type'  => 'person',
	'id'    => $person->getId(),
	'body'  => $person->getName(),
]);

Running queries

Queries against the search index are run by creating a query, then creating a search using the query and finally executing the query using the provided service.

Here's an example:

// Get an instance of ElasticSearchService
$service = app(ElasticsearchServiceContract::class);

// Create the query
$query = (new BoolQuery())
    ->addMust(
        (new TermQuery())
            ->setField('user')
            ->setValue('kimchy'))
    ->addFilter(
        (new TermQuery())
            ->setField('tag')
            ->setValue('tech'))
    ->addMustNot(
        (new RangeQuery())
            ->setField('age')
            ->setGreaterThanOrEquals(18)
            ->setLessThanOrEquals(40))
    ->addShould(
        (new TermQuery())
            ->setField('tag')
            ->setValue('wow'))
    ->addShould(
        (new TermQuery())
            ->setField('tag')
            ->setValue('elasticsearch'));

// Create the search
$search = $service->createSearch()
    ->setIndex('index')
    ->setType('document')
    ->setQuery($query)
    ->setSize(50)
    ->setPage(1);

// Execute the search to retrieve the results
$result = $service->execute($search);

You can also perform raw queries:

$service = app(ElasticsearchServiceContract::class);

$result = $service->search([
    'index' => 'index',
    'type'  => 'document',
    'body'  => [
        'query' => [
            'bool' => [
                'must' => [
                    'term' => ['user' => 'kimchy']
                ],
                'filter' => [
                    'term' => ['tag' => 'tech']
                ],
                'must_not' => [
                    'range' => [
                        'age' => ['gte' => 10, 'lte' => 20]
                    ]
                ],
                'should' => [
                    [
                        'term' => ['tag' => 'wow']
                    ],
                    [
                        'term' => ['tag' => 'elasticsearch']
                    ]
                ],
            ]
        ],
        'size' => 50,
        'from' => 0
    ],
]);

Creating and applying index migrations

Sometimes you need to make a change to an index mapping that requires data to be re-indexed. However, most of the time you don't need to actually index everything into Elasticsearch again, instead it is enough to just copy the data internally from your original index to a new one. This process can be performed seamlessly without downtime.

Requirements

• You must add the CreateMigrationCommand and ApplyMigrationCommand commands to your console kernel
• Your Elasticsearch instance must support the /_reindex API. This is normally the case, however, Amazon Elasticsearch Service doesn't support it if you're using Elasticsearch 2.3 or older.

Creating a migration

• Change your index definition (e.g. config/search/your-index.php) according to your needs
• Run php artisan elastic:migrations:create config/search/your-index.php)

This will create a directory named versions as well as a timestamped copy of your index definition file.

Applying a migration

• Run php artisan elastic:migrations:migrate config/search/your-index.php

If you haven't run migrations before, your index will be replaced by an alias of the same name once the new index has been created. The next time you apply a migration, the alias will simply be updated.

If your documents are very large you may want to decrease the batch size used during re-indexing to prevent Elasticsearch from running out of memory. You can do so by passing --batchSize=X to the elastic:migrations:migrate command. If the option is omitted, the default value of 1000 is used.

Updating dynamic index settings

There is a console command (elastic:index:settings:update) that you can use to update certain dynamic index settings such as the refresh interval or the number of replicas. Simply register it in your console kernel to start using it.

Using index prefixes

This library supports specifying a prefix for index names, similarly to how many frameworks support cache prefixes in order to allow multiple applications to share the same cache. This means you can use a single Elasticsearch cluster for multiple projects (or for example a shared one for the "dev" and "staging" environment).

The prefix used is specified by the configuration file (config/elasticsearch.php). The default behavior is to read the prefix from the ELASTICSEARCH_INDEX_PREFIX environment variable.

If you have an index named content and you specify foo as a prefix, the index will be named foo_content. If you need custom logic you can override getPrefixedIndexName() in ElasticsearchService.

Prefixing is supported for index migrations too, in which case the both the indices and the aliases created are prefixed.

Pagerfanta integration

There is a Pagerfanta adapter included for easy pagination. However, it is optional, so if you intend to use it you must require the pagerfanta/pagerfanta package explicitly.

Contributing

Please read the guidelines.

Running tests

Clone the project and install its dependencies by running:

composer install

Run the following command to run the test suite:

composer test

License

See LICENSE.