In-Depth Example¶

Dynamic App with Database¶

Similar to deploying a simple static HTML app, 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 a namespace for your application. In this example, we’ll name the application “helloworldapp2”:

$ dotcloud create helloworldapp2
Created application "helloworldapp2"

Build File with Two Services¶

The 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:

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:

<?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();'));

?>

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 helloworldapp2 .

Set Up Your Database¶

Get your root database credentials:

$ dotcloud info helloworldapp2.db
build_revision: rsync-1308704705.29
cluster: wolverine
config:
    mysql_password: OLZeLLBdKFAiI2lGqSn4
    mysql_serverid: -1
created_at: 1308704715.008709
ports:
-   name: ssh
    url: ssh://dotcloud@fce95d9a.dotcloud.com:8773
-   name: mysql
    url: mysql://root:OLZeLLBdKFAiI2lGqSn4@fce95d9a.dotcloud.com:8774
state: running
type: mysql

Create your database and database access credentials as follows:

$ dotcloud run helloworldapp2.db -- mysql -u root -pOLZeLLBdKFAiI2lGqSn4
mysql> CREATE USER 'helloappuser' IDENTIFIED BY 'helloworldpassword';
Query OK, 0 rows affected (0.02 sec)
mysql> CREATE DATABASE helloworldapp2;
Query OK, 1 row affected (0.00 sec)
mysql> GRANT ALL ON helloworldapp2.* TO 'helloappuser'@'%';
Query OK, 0 rows affected (0.00 sec)
mysql> FLUSH PRIVILEGES;
Query OK, 0 rows affected (0.00 sec)

Restart Your App¶

$ dotcloud restart helloworldapp2.www

Try Your App¶

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

$ dotcloud url helloworldapp2

Deleting Services¶

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

$ dotcloud destroy helloworldapp2.www
Please confirm destruction [yn]: y
Destroy for "helloworldapp2.www" triggered.

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 helloworldapp2
Please confirm destruction [yn]: y
Destroy for "helloworldapp2" triggered.

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. A few seconds after the destroy command is sent, there is no way to recover your data.

How It Works