# Databases

A **cloud database** is a MySQL relational database service that allows
customers to programatically provision database instances of varying virtual
resource sizes without the need to maintain and/or update MySQL.

## Getting started

### 1. Instantiate a Rackspace client.

```php
use OpenCloud\Rackspace;
use OpenCloud\Common\Constants\State;

$client = new Rackspace(Rackspace::US_IDENTITY_ENDPOINT, array(
    'username' => '<YOUR RACKSPACE CLOUD ACCOUNT USERNAME>',
    'apiKey'   => '<YOUR RACKSPACE CLOUD ACCOUNT API KEY>'
));
```

### 2. Create a database server instance.

```php
$databaseService = $client->databaseService('cloudDatabases', 'DFW');

$twoGbFlavor = $databaseService->flavor(3);

$dbInstance = $databaseService->instance();
$dbInstance->name = 'Demo database instance';
$dbInstance->volume = new stdClass();
$dbInstance->volume->size = 20; // GB
$dbInstance->flavor = $twoGbFlavor;
$dbInstance->create();

$dbInstance->waitFor(State::ACTIVE, null, function ($dbInstance) {

    printf("Database instance build status: %s\n", $dbInstance->status);

});
```

The example above creates a database server instance with 20GB of disk space and
2GB of memory, then waits for it to become ACTIVE.

### 3. Create a database on the database server instance.

```php
$db = $dbInstance->database();
$db->name = 'demo_db';

$db->create();
```

The example above creates a database named `demo_db` on the database server
instance created in the previous step.

### 4. Create database user and give it access to database.

```php
$user = $dbInstance->user();
$user->name = 'demo_user';
$user->password = 'h@X0r!';
$user->databases = array('demo_db');

$user->create();
```

The example above creates a database user named `demo_user`, sets its password
and gives it access to the `demo_db` database created in the previous step.

### 5. Optional step: Create a load balancer to allow access to the database from the Internet.

The database created in the previous step can only be accessed from the Rackspace
private network (aka `SERVICENET`). If you have a cloud server instance in the same
region as the database server instance, you will be able to connect to the database
from that cloud server instance.

If, however, you would like to access the database from the Internet, you will 
need  to create a load balancer with an IP address that is routable from the 
Internet and attach the database server instance as a back-end node of this load
balancer.

```php
$loadBalancerService = $client->loadBalancerService('cloudLoadBalancers', 'DFW');

$loadBalancer = $loadBalancerService->loadBalancer();

$loadBalancer->name = 'Load balancer - DB';
$loadBalancer->addNode($dbInstance->hostname, 3306);
$loadBalancer->port = 3306;
$loadBalancer->protocol = 'MYSQL';
$loadBalancer->addVirtualIp('PUBLIC');

$loadBalancer->create();

$loadBalancer->waitFor(State::ACTIVE, null, function ($lb) {
    printf("Load balancer build status: %s\n", $lb->status);
});

foreach ($loadBalancer->virtualIps as $vip) {
    if ($vip->type == 'PUBLIC') {
        printf("Load balancer public %s address: %s\n", $vip->ipVersion, $vip->address);
    }
}
```

In the example above, a load balancer is created with the database server
instance as its only back-end node. Further, this load balancer is configured
to listen for MySQL connections on port 3306. Finally a virtual IP address (VIP)
is configured in the `PUBLIC` network address space so that this load balancer
may receive connections from the Internet. 

Once the load balancer is created and becomes `ACTIVE`, it's Internet-accessible
IP addresses are printed out. If you connect to any of these IP addresses on port
3306 using the MySQL protocol, you will be connected to the database created in
step 3.