Sunday, December 18, 2011

Configuring Zend Framework apps for Windows Azure

Building web applications is nothing new anymore, as we've been doing it since the early days of the internet, but we've always done this on a single system. Even when Zend Framework came round, we kept doing the same thing and build apps for a single environment.
But as I've discussed already in my previous article, developing for the cloud requires another approach.

As you can see, your system now falls appart into all different components that are systems by themselves. And each system has its own purpose, completely independent from each other.

With Zend Framework developing applications running on these separate compontents becomes really easy. It's like having your cloud toolbox right in your pocket.

Databases

With Zend Framework, connecting to databases is really easy and swapping out a database brand is just a matter of modifying your configuration application/configs/application.ini.

resources.db.adapter = "pdo_mysql"
resources.db.params.host = "10.20.30.40"
resources.db.params.username = "user1"
resources.db.params.password = "secret"
resources.db.params.dbname = "db1"
resources.db.isDefaultTableAdapter = true

Even if you need to connect to multiple databases, you can just pile them up as configuration setting and be done with it.

resources.multidb.server1.adapter = "pdo_mysql"
resources.multidb.server1.host = "10.20.30.40"
resources.multidb.server1.username = "user1"
resources.multidb.server1.password = "secret1"
resources.multidb.server1.dbname = "db1"
resources.multidb.server1.default = true
resources.multidb.server2.adapter = "pdo_pgsql"
resources.multidb.server2.host = "10.20.30.41"
resources.multidb.server2.username = "user2"
resources.multidb.server2.password = "secret2"
resources.multidb.server2.dbname = "db2"

resources.multidb.server3.adapter = "pdo_sqlite"
resources.multidb.server3.dbname = APPLICATION_PATH "/files/db/project.db"

But this is just the basics. When dealing with the cloud you often get a connection string for the host, so it's real easy to hook up to an relational database in the cloud. Here's an example to connecting to SQL Azure.

resources.db.adapter = "SQLSRV"
resources.db.params.host = "abcdefghijk.database.windows.net"
resources.db.params.port = 1234
resources.db.params.username = "user1"
resources.db.params.password = "secret"
resources.db.params.dbname = "db1"
resources.db.isDefaultTableAdapter = true

Bottom line, no worries connecting to a cloud database. Zend Framework has your back!

Sessions

As you want to assist your visitors as much as possible, you probably want to use sessions in your application. If you don't configure anything, PHP stores session on your filesystem by default and so does Zend Framework.

For the cloud, you don't want to write to your local filesystem, so you set up session storage. I chose to use the SQL Azure server I already had setup using the following settings.

resources.session.use_only_cookies = true
resources.session.gc_maxlifetime = 864000
resources.session.remember_me_seconds = 864000
resources.session.saveHandler.class = "Zend_Session_SaveHandler_DbTable"
resources.session.saveHandler.options.name = "session"
resources.session.saveHandler.options.primary = "id"
resources.session.saveHandler.options.modifiedColumn = "modified"
resources.session.saveHandler.options.dataColumn = "data"
resources.session.saveHandler.options.lifetimeColumn = "lifetime"

No further changes need to be done as all fields are defined and this Zend_Session_SaveHandler_DbTable takes care of all the rest.

Caching

Just like databases, providing caching for your application requires just a few simple configuration settings, this example sets up a memcache service.

resources.cachemanager.memcached.frontend.name = Core
resources.cachemanager.memcached.frontend.options.automatic_serialization = On
resources.cachemanager.memcached.backend.name = Libmemcached
resources.cachemanager.memcached.backend.options.servers.one.host = localhost
resources.cachemanager.memcached.backend.options.servers.one.port = 11211
resources.cachemanager.memcached.backend.options.servers.one.persistent = On

Caching on the cloud requires a little different approach as most cloud services offer their own flavor of caching, making it difficult to find a PHP driver that is capable to access this cloud caching layer. But don't let this stop you in moving to the cloud. Windows Azure provides a superb caching platform, and I'll show you later in these series how to modify your application as it requires a little tweek on the configuration of your Windows Azure installation.

Storage

Uploading and distributing files can be considered as an importan part of any application, and with Zend Framework you can manage file uploads relatively simple using Zend_Form and Zend_File.

An example would be to upload a small image.

public function uploadAction()
{
$adapter = new Zend_File_Transfer_Adapter_Http();

$adapter->setDestination(APPLICATION_PATH '/files/upload');

if (!$adapter->receive()) {
$messages = $adapter->getMessages();
echo implode("\n", $messages);
}
$this->view->filename = $adapter->getFileName('avatar', false);
}

Saving into a specific location is done with $adapter->setDestination(), but this still requires the usage of a local location! And we know that in the cloud saving locally has no use! Luckily for you, Zend Framework has a bunch of components that will allow you to store files onto a Windows Azure Storage instance.

 public function uploadAction()
{
$config = new Zend_Config_Ini(APPLICATION_PATH . '/configs/api.ini', APPLICATION_ENV);

$azure = new My_Cloud_WindowsAzure_AzureStorage(
$config->azure->storage->account,
$config->azure->storage->primkey);

$container = $config->azure->storage->container;

$adapter = new Zend_File_Transfer_Adapter_Http();
$adapter->setDestination(APPLICATION_PATH '/files/upload');

if (!$adapter->receive()) {
$messages = $adapter->getMessages();
echo implode("\n", $messages);
}

$storageClient = new Zend_Service_WindowsAzure_Storage_Blob(
My_Cloud_WindowsAzure_AzureStorage::AZURE_STORAGE_HOST,
$azure->getAccountName(), $azure->getPrimaryKey());

$result = null;

if (!$storageClient->containerExists($container)) {
$result = $storageClient->createContainer($container);
$storageClient->setContainerAcl($container,
Zend_Service_WindowsAzure_Storage_Blob::ACL_PUBLIC_CONTAINER);
}

$fileName = $adapter->getFileName('resume', true);
$result = $storageClient->putBlob(
$container, basename($fileName), $fileName
);

$this->view->filename = basename($fileName);
$this->view->location = sprintf('http://%s.%s/%s/%s',
$azure->getAccountName(),
My_Cloud_WindowsAzure_AzureStorage::AZURE_STORAGE_HOST,
$config->azure->storage->container,
$result->Name);
}

As you can see, you only need to add a little more functionality to the first example. But once you have everything in place, nothing can stop you achieving your goals.

; These are local configuration settings
; Primarily used to access API's using credential tokens
[production]
...
azure.storage.account = "myblobstorageaccount1"
azure.storage.primkey = "fjldjljdlfjadladjsljdfljfdljd/akjddfjldfjjd22kajdajfei3234ajldjfjklajlajd=="
azure.storage.container = "myblobstoragecontainer"
...

[staging: production]
[testing: production]
[development: production]

In this example I used an api.ini which is very convenient to store your most import settings like account names, api keys and passwords to various api services. It's just a file containing key-value pairs for easy configuration. In this case my INI settings look like the following listing.

Next

Now that we've talked about the specific settings in your Zend Framework application it's about time we set up our environment, download all the tools, register for a Windows Azure account and get started with running our Zend Framework app in the cloud. So stay tuned for more.

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.