Elasticsearch-php: Error when creating an alias in an index template

[hanneskaeufler]

Hi,

I want to create an index template roughly like so:

        $this->getElasticsearchClient()
            ->indices()
            ->putTemplate([
                'name' => 'my_template',
                'body' => [
                    'template' => 'index-matcher-*',
                    'aliases' => [
                        // register an alias for each new index so that we can
                        // perform index migrations without downtime
                        // only use the read- prefixed indices to query for data
                        'read-{index}' => [],
                    ],
                ],
            ])
        ;

However, I get a 400 BadRequest with the error ElasticsearchIllegalArgumentException[No alias specified]

If I use 'read-{index}' => ['a' => 'b'], instead, it works.
Are options to the index alias mandatory? Specifying dummy options just to have an associative array seems to circumvent that?

[polyfractal]

Ah, this is an unfortunate quirk of PHP and json_encode. You can specify an empty JSON object ({}) by using an explicit empty PHP object. Try this:

 $this->getElasticsearchClient()
            ->indices()
            ->putTemplate([
                'name' => 'my_template',
                'body' => [
                    'template' => 'index-matcher-*',
                    'aliases' => [
                        // register an alias for each new index so that we can
                        // perform index migrations without downtime
                        // only use the read- prefixed indices to query for data
                        'read-{index}' => new \stdClass(),
                    ],
                ],
            ])
        ;

If that doesn't work, I'll break out the debugger and see what's going on. :)

[hanneskaeufler]

Hi, thanks! I figured something like this might be going on. stdClass works.