runECSTask.php

 $client = new EcsClient([
  'version' => 'latest',
  'region'  => 'ap-southeast-2'
]);

$client->runTask([
   'cluster'              => self::CONFIG[$environment]['cluster'],
   'launchType'           => 'FARGATE',
   'count'                => 1,
   'taskDefinition'       => self::CONFIG[$environment]['taskDefinition'],
   'networkConfiguration' => [
   'awsvpcConfiguration' => [
   'assignPublicIp' => 'ENABLED',
   'securityGroups' => self::CONFIG[$environment]['securityGroups'],
   'subnets'        => self::CONFIG[$environment]['subnets']
    ],
  ],
  'startedBy'            => $event->info
]);