Appsync's graphql subscription not working with PHP5

Question

Can anyone help me with a working example of graphql subscription with php5 and AWS Appsync or php5 WebSocket client which works with Appsync? I am trying textalk but haven't got any success.

<?php
require(dirname(dirname(__FILE__)) . '/graphql/vendor/autoload.php');

use WebSocket\Client;

$query = <<<'GRAPHQL'
subscription onCreateProfile{
  onCreateBatch {
    hotelId
    batchId
    profiles {
      id
    }
  }
}
GRAPHQL;

$appSyncURL = 'wss://pbnblnr7xxxxxxxxxxxx.appsync-realtime-api.ap-south-1.amazonaws.com/graphql';
$context = stream_context_create();
stream_context_set_option($context, 'ssl', 'verify_peer', false);
stream_context_set_option($context, 'ssl', 'verify_peer_name', false);
$client = new WebSocket\Client($appSyncURL, [
    'timeout' => 60, // 1 minute time out
    'context' => $context,
    'headers' => [
        'x-api-key' => 'APIKEY',
    ],
]);
$client->send($query);
echo $client->receive();
$client->close();

Running above snippet gives below error:

$ php subscription.php
{"payload":{"errors":[{"message":"NoProtocolError","errorCode":400}]},"type":"connection_error"}PHP Fatal error:  Uncaught WebSocket\ConnectionException: Empty read; connection dead?  Stream state: {"crypto":{"protocol":"UNKNOWN","cipher_name":"TLS_AES_256_GCM_SHA384","cipher_bits":256,"cipher_version":"TLSv1.3"},"timed_out":false,"blocked":true,"eof":true,"stream_type":"tcp_socket\/ssl","mode":"r+","unread_bytes":0,"seekable":false} in /var/www/html/demo/graphql/vendor/textalk/websocket/lib/Base.php:316
Stack trace:
#0 /var/www/html/demo/graphql/vendor/textalk/websocket/lib/Base.php(299): WebSocket\Base->throwException('Empty read; con...')
#1 /var/www/html/demo/graphql/vendor/textalk/websocket/lib/Base.php(159): WebSocket\Base->read(2)
#2 /var/www/html/demo/graphql/vendor/textalk/websocket/lib/Base.php(149): WebSocket\Base->receiveFragment()
#3 /var/www/html/demo/graphql/vendor/textalk/websocket/lib/Base.php(272): WebSocket\Base->receive()
#4 /var/www/html/demo/graphql/subscription.php(31): WebSocket\Base->close()
#5 {main}
  thrown in /var/www/html/demo/graphql/vendor/textalk/websocket/lib/Base.php on line 316

So has anyone tried graphQL subscriptions with php5? My requirement is to consume Graphql Subscription in PHP application (in backend). I know graphQL subscription would work fine in frontend through javascript WebSocket client. But I've to use graphql subscriptions in PHP5 application.

Any help will be appreciated!

Answer 1

I've figured it out and now it is working fine with >= PHP 5.6.

Here is the working example of the same, in case anyone needs it.

https://github.com/roshanlabh/php-appsync-consumer-example/blob/master/appsync-subscription.php