How To: PHP with Astra

One of the reasons I created my blog here was to be able to quickly create public content for tasks that I have in various stages of completion. Normally this kind of information I create would stay in cryptic files that most people would not be able to understand. Yesterday Legacy Driver section was added to Astra Docs including the PHP Driver. Now in a successful fashion I am able to quickly go back and get some PHP Driver work I had created early on in my journey here at DataStax. Be sure to get comfortable with the Prerequisites and Procedures before continuing.

Fun Fact: PHP is the 3rd programming language I learned and I have used PHP since the 90s.

Why PHP and Astra?

Well, because we all still have legacy apps and now you want to move them to cassandra. Astra is the perfect place to work on that migration and you can do it for free on the free tier. Since PHP is used in tons of websites and usually coupled with mysql under the hood this is a great data modeling and astra experience. I wont get into data modeling too much here, but reach out if you want to have that discussion. I do not work with PHP anymore, but for the purpose of this blog, I am going to expose some work I have done to hook PHP to Astra.

You can leverage Astra with PHP in three ways:

Convert the PHP insert/update/delete/select to curl.
Minimally convert code and implement the driver.
Stop using php server side and use rest api with js/jquery. #winning

What Environment?

Node History for Php 7.1 w/ Cassandra on a Centos 7.4 Vagrant VM:

wget -q http://rpms.remirepo.net/enterprise/remi-release-7.rpm
wget -q https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
rpm -i remi-release-7.rpm epel-release-latest-7.noarch.rpm
yum install yum-utils
yum-config-manager --enable remi-php71
yum install php php-devel php-pear
yum install automake cmake gcc-c++ git libtool pcre-devel 
yum install gmp gmp-devel

wget http://downloads.datastax.com/cpp-driver/centos/7/dependencies/libuv/v1.8.0/libuv-1.8.0-1.el7.centos.x86_64.rpm
wget http://downloads.datastax.com/cpp-driver/centos/7/dependencies/libuv/v1.8.0/libuv-devel-1.8.0-1.el7.centos.x86_64.rpm
rpm -ivh libuv-1.8.0-1.el7.centos.x86_64.rpm
rpm -ivh libuv-devel-1.8.0-1.el7.centos.x86_64.rpm
yum install libuv libuv-devel
wget https://downloads.datastax.com/cpp-driver/centos/7/cassandra/v2.7.0/cassandra-cpp-driver-2.7.0-1.el7.centos.x86_64.rpm
wget https://downloads.datastax.com/cpp-driver/centos/7/cassandra/v2.7.0/cassandra-cpp-driver-devel-2.7.0-1.el7.centos.x86_64.rpm
rpm -ivh cassandra-cpp-driver-2.7.0-1.el7.centos.x86_64.rpm 
rpm -ivh cassandra-cpp-driver-devel-2.7.0-1.el7.centos.x86_64.rpm 
pecl install cassandra
php -r "echo php_ini_loaded_file();"
nano /etc/php.ini 

Add this to php.ini:

; DataStax PHP Driver for Apache Cassandra
extension=cassandra.so

With the above environment working for cassandra driver and php I can execute our test script against astra:

<?php 

$ssl = Cassandra::ssl()
	->withTrustedCerts('/vagrant/ca.crt')
	->withClientCert('/vagrant/cert')
	->withPrivateKey('/vagrant/key', 'passphrase')
	->build();
$cluster = Cassandra::cluster()
	->withSSL($ssl)
	->withCredentials("demo", "demo2020")
	->withContactPoints('[databaseid]-us-east1.db.astra.datastax.com')
	->withPort(31025)
	->build();
$session = $cluster->connect();
$result = $session->execute('SELECT * FROM demo');
foreach ($result as $row) {
    printf("The result is \"%s\".\n", $row['result']);
}
 
?>

What Code Changes?

Now that the environment and demo works, lets look at some code changes i had to make in the application:

BEFORE:

function register($_INPUT) {

if(
	isset($_INPUT['registerSubmit']) && 
	$_INPUT['password'] == $_INPUT['confirm']
) {
	$query = "INSERT INTO `users` (`sessionid`,`usertype`,`password`,`email`,`ip`) VALUES('".session_id()."', 'member', PASSWORD('".$_POST['password']."'), '".$_POST['email']."', '".$_SERVER['REMOTE_ADDR']."');";
	$result = mysql_query($query) or mail('me',"register query fail",$query);
	$insert_id = mysql_insert_id();
	$_SESSION['userid'] = $insert_id;	
}

AFTER:

function register($_INPUT) {
	if(
	   	isset($_INPUT['registerSubmit']) &&
	    $_INPUT['password'] == $_INPUT['confirm']
	) {
	   	$query = "INSERT INTO demo.users (id,sessionid,usertype,password,email,ip) VALUES(uuid(), '".session_id()."', 'member', '".$_POST['password']."', '".$_POST['email']."', '".$_SERVER['REMOTE_ADDR']."');";

	// astra cassandra php settings
	$ssl = Cassandra::ssl()
		->withTrustedCerts('/vagrant/ca.crt')
		->withClientCert('/vagrant/cert')
		->withPrivateKey('/vagrant/key', 'passphrase')
	   	->build();
	$cluster = Cassandra::cluster()
		->withSSL($ssl)
		->withCredentials("demo", "demo2020")
		->withContactPoints('[databaseid]-us-east1.db.astra.datastax.com')
		->withPort(31025)
		->build$
	$options = new Cassandra\ExecutionOptions(array('consistency' => Cassandra::CONSISTENCY_ALL));
	$session = $cluster->connect();
	$result = $session->execute($query,$options);
}

Notice anything different other than inherit differences for the cassandra driver? Yup, no mysql_insert_id() here and uuid() function in the insert. When migrating a legacy app to cassandra, not only do you have to think outside of the box for data modeling, you also have to be mindful in the application layer. To solve this problem, I completely removed the dependency on a user id in the application. We dont need no stinking incremental ids in cassandra!!

What’s Next?

Are you still using PHP? Reach out, I can show you how to modernize your application experience with futureproof modern and serverless applications. If you are unable to modernize your app completely and you want to migrate to Astra or Cassandra using this Legacy PHP Driver, I can help out with that too.

How can I help you with Astra?

SRM

Find me over on the Astra Slack to ask me any questions about Astra. Also let’s chat if you have something kewl you did with Astra and you want me to feature it in my blog. Look below or to the right for more ways to find me.

Astra + PHP