:title: In-Depth Example
:description: Deploy a more advanced, database-backed application with just a few steps on dotCloud.
:keywords: dotCloud, Getting started, dotCloud documentation, dynamic app, Php and MySQL, helloworldapp2, dotCloud.yml, connect database, push code, set up database, restart app, try your app, deleting services

.. rst-class:: next

:doc:`how-it-works`


In-Depth Example
================

.. include:: ../dotcloud2note.inc

Dynamic App with Database
-------------------------

Similar to deploying a :doc:`simple static HTML app <quickstart>`,
deploying a dynamic app with a database takes just a few steps. Instead
of using the static service, we will be choosing a service based on the
language of the app we will deploy. In addition, we will add a database
that will back the app. For this example, we are using PHP and MySQL.

To get ready, create your application in the flavor of your choice. In this
example, we'll name the application "helloworldapp2" and use the default
flavor::

  dotcloud create helloworldapp2

Build File with Two Services
----------------------------

The dotCloud Build File defines the services that exist within your application.
In our previous example, we had one service named "www" that hosted
static HTML files. In this example, we will change the "www" service to
a different technology, and add a database service.

Create your dotcloud.yml file at the root of your application:

.. code-block:: yaml

  www:
    type: php
  db:
    type: mysql


Connecting the Database
-----------------------

To connect your front-end web service to your database, you will need to
add some code that detects the presence of the dotCloud environment and
imports the database URL.

For example, to access a MySQL database using the PHP mysqli module,
create a file named index.php with the following. This sample app prints
some information about the database connection:

.. code-block:: php

  <?php

  # Import environment settings from dotCloud
  $envjson = json_decode(file_get_contents("/home/dotcloud/environment.json"),true);

  # Create MySQL Connection
  $mysqli = new mysqli($envjson['DOTCLOUD_DB_MYSQL_HOST'],
                       'helloappuser',         # username
                       'helloworldpassword',   # password
                       'helloworldapp2',       # db name
                       $envjson['DOTCLOUD_DB_MYSQL_PORT']);

  print_r($mysqli->query('SELECT now();')->fetch_row());

  ?>


Push Your Code
--------------

Now that you have prepared your code by creating a Build File, you can
push the code to dotCloud with the following command::

  dotcloud push


Set Up Your Database
--------------------

Create your database with access credentials as follows::

  dotcloud run db -- mysql

This command will open up a command prompt for mysql. There you can enter the following commands::

  CREATE USER 'helloappuser' IDENTIFIED BY 'helloworldpassword';
  CREATE DATABASE helloworldapp2;
  GRANT ALL ON helloworldapp2.* TO 'helloappuser'@'%';
  FLUSH PRIVILEGES;
  quit


Restart Your PHP Frontend
-------------------------

::

  dotcloud restart www.0


Try Your App
------------

Get the URL to access it with the ``url`` command. Open it in a browser!

::

  dotcloud url

Or, you can open up your application in a web browser directly from the
command line with the ``open`` command::

  dotcloud open www


Deleting Services
-----------------

If you don't need a service anymore, you can delete it with the ``destroy``
command::

  dotcloud destroy www

Note, however, that it will be recreated automatically on the next ``push``,
unless you remove it from ``dotcloud.yml``.

You can also destroy a whole application::

  dotcloud destroy

.. note::

  The destruction is asynchronous; so don't be surprised if your service
  or application still shows up in ``dotcloud list`` for a while. It should
  go away after a few minutes.

.. warning::

  Service or application destruction is permanent, and cannot be undone.
  After the ``destroy`` command is sent, there is no way to recover your data.


.. rst-class:: next

:doc:`how-it-works`