PHP: Error in creating Server Instance in Google Cloud Compute - php

Question

While using Google Cloud Compute's API in PHP, I am able to start, stop, delete instances as well as create and delete disks.
However, when trying to create an Instance, I keep getting this error
Invalid value for field 'resource.disks'
PHP Fatal error: Uncaught exception 'Google_Service_Exception' with message 'Error calling POST https://www.googleapis.com/compute/v1/projects/project/zones/zone/instances: (400) Invalid value for field 'resource.disks': ''. Boot disk must be specified.' in /var/www/html/google/google-api-php-client/src/Google/Http/REST
Here is the request I am making
self::connectClient();
$computeService = new Google_Service_Compute($this->client);
if ($this->client->getAccessToken())
{
$googleNetworkInterfaceObj = new Google_Service_Compute_NetworkInterface();
$network = self::DEFAULT_NETWORK;
$googleNetworkInterfaceObj->setNetwork($network);
$diskObj = self::getDisk($instance_name);
$new_instance = new Google_Service_Compute_Instance();
$new_instance->setName($instance_name);
$new_instance->setMachineType(self::DEFAULT_MACHINE_TYPE);
$new_instance->setNetworkInterfaces(array($googleNetworkInterfaceObj));
$new_instance->setDisks(array(
"source"=>$diskObj->selfLink,
"boot"=>true,
"type"=>"PERSISTENT",
"deviceName"=>$diskObj->name,
));
$insertInstance = $computeService->instances->insert(self::DEFAULT_PROJECT,self::DEFAULT_ZONE_NAME, $new_instance);
Any help will be highly appreciated, thank you.

Answer 1

Ok the solution was really simple (and silly)
Instead of
$new_instance->setDisks(array(
"source"=>$diskObj->selfLink,
"boot"=>true,
"type"=>"PERSISTENT",
"deviceName"=>$diskObj->name,
));
It's supposed to be
$new_instance->setDisks(array(
array(
'source'=>self::getDisk($instance_name)->selfLink,
'boot'=>true,
'type' => "PERSISTENT",
'deviceName'=>self::getDisk($instance_name)->name,
)
));