Deploying PHP applications in tsuru

Overview

This document is a hands-on guide to deploying a simple PHP application in Tsuru. The example application will be a very simple Wordpress project associated to a MySQL service. It’s applicable to any php over apache application.

Creating the app within tsuru

To create an app, you use app-create command:

$ tsuru app-create <app-name> <app-platform>

For PHP, the app platform is, guess what, php! Let’s be over creative and develop a never-developed tutorial-app: a blog, and its name will also be very creative, let’s call it “blog”:

$ tsuru app-create blog php

To list all available platforms, use platform-list command.

You can see all your applications using app-list command:

$ tsuru app-list
+-------------+-------------------------+---------+--------+
| Application | Units State Summary     | Address | Ready? |
+-------------+-------------------------+---------+--------+
| blog        | 0 of 0 units in-service |         | No     |
+-------------+-------------------------+---------+--------+

Once your app is ready, you will be able to deploy your code, e.g.:

$ tsuru app-list
+-------------+-------------------------+-------------+--------+
| Application | Units State Summary     | Address     | Ready? |
+-------------+-------------------------+-------------+--------+
| blog        | 0 of 1 units in-service |             | Yes    |
+-------------+-------------------------+-------------+--------+

Application code

This document will not focus on how to write a php blog, you can download the entire source direct from wordpress: http://wordpress.org/latest.zip. Here is all you need to do with your project:

# Download and unpack wordpress
$ wget http://wordpress.org/latest.zip
$ unzip latest.zip
# Preparing wordpress for tsuru
$ cd wordpress
# Notify tsuru about the necessary packages
$ echo php5-mysql > requirements.apt
# Preparing the application to receive the tsuru environment related to the mysql service
$ sed "s/'database_name_here'/getenv('MYSQL_DATABASE_NAME')/; \
            s/'username_here'/getenv('MYSQL_USER')/; \
            s/'localhost'/getenv('MYSQL_HOST')/; \
            s/'password_here'/getenv('MYSQL_PASSWORD')/" \
            wp-config-sample.php  > wp-config.php
# Creating a local git repository
$ git init
$ git add .
$ git commit -m 'initial project version'

Git deployment

When you create a new app, tsuru will display the Git remote that you should use. You can always get it using app-info command:

$ tsuru app-info --app blog
Application: blog
Repository: git@git.tsuru.io:blog.git
Platform: php
Teams: tsuruteam
Address:

The git remote will be used to deploy your application using git. You can just push to tsuru remote and your project will be deployed:

$ git push git@git.tsuru.io:blog.git master
Counting objects: 119, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (53/53), done.
Writing objects: 100% (119/119), 16.24 KiB, done.
Total 119 (delta 55), reused 119 (delta 55)
remote:
remote:  ---> Tsuru receiving push
remote:
remote: From git://cloud.tsuru.io/blog.git
remote:  * branch            master     -> FETCH_HEAD
remote:
remote:  ---> Installing dependencies
#####################################
#          OMIT (see below)         #
#####################################
remote:  ---> Restarting your app
remote:
remote:  ---> Deploy done!
remote:
To git@git.tsuru.io:blog.git
   a211fba..bbf5b53  master -> master

If you get a “Permission denied (publickey).”, make sure you’re member of a team and have a public key added to tsuru. To add a key, use key-add command:

$ tsuru key-add ~/.ssh/id_dsa.pub

You can use git remote add to avoid typing the entire remote url every time you want to push:

$ git remote add tsuru git@git.tsuru.io:blog.git

Then you can run:

$ git push tsuru master
Everything up-to-date

And you will be also able to omit the --app flag from now on:

$ tsuru app-info
Application: blog
Repository: git@git.tsuru.io:blog.git
Platform: php
Teams: tsuruteam
Address: blog.cloud.tsuru.io
Units:
+--------------+---------+
| Unit         | State   |
+--------------+---------+
| 9e70748f4f25 | started |
+--------------+---------+

For more details on the --app flag, see “Guessing app names” section of tsuru command documentation.

Listing dependencies

In the last section we omitted the dependencies step of deploy. In tsuru, an application can have two kinds of dependencies:

• Operating system dependencies, represented by packages in the package manager of the underlying operating system (e.g.: yum and apt-get);
• Platform dependencies, represented by packages in the package manager of the platform/language (e.g. in Python, pip).

All apt-get dependencies must be specified in a requirements.apt file, located in the root of your application, and pip dependencies must be located in a file called requirements.txt, also in the root of the application. Since we will use MySQL with PHP, we need to install the package depends on just one apt-get package: php5-mysql, so here is how requirements.apt looks like:

php5-mysql

You can see the complete output of installing these dependencies bellow:

% git push tsuru master
#####################################
#                OMIT               #
#####################################
Counting objects: 1155, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (1124/1124), done.
Writing objects: 100% (1155/1155), 4.01 MiB | 327 KiB/s, done.
Total 1155 (delta 65), reused 0 (delta 0)
remote: Cloning into '/home/application/current'...
remote: Reading package lists...
remote: Building dependency tree...
remote: Reading state information...
remote: The following extra packages will be installed:
remote:   libmysqlclient18 mysql-common
remote: The following NEW packages will be installed:
remote:   libmysqlclient18 mysql-common php5-mysql
remote: 0 upgraded, 3 newly installed, 0 to remove and 0 not upgraded.
remote: Need to get 1042 kB of archives.
remote: After this operation, 3928 kB of additional disk space will be used.
remote: Get:1 http://archive.ubuntu.com/ubuntu/ quantal/main mysql-common all 5.5.27-0ubuntu2 [13.7 kB]
remote: Get:2 http://archive.ubuntu.com/ubuntu/ quantal/main libmysqlclient18 amd64 5.5.27-0ubuntu2 [949 kB]
remote: Get:3 http://archive.ubuntu.com/ubuntu/ quantal/main php5-mysql amd64 5.4.6-1ubuntu1 [79.0 kB]
remote: Fetched 1042 kB in 1s (739 kB/s)
remote: Selecting previously unselected package mysql-common.
remote: (Reading database ... 23874 files and directories currently installed.)
remote: Unpacking mysql-common (from .../mysql-common_5.5.27-0ubuntu2_all.deb) ...
remote: Selecting previously unselected package libmysqlclient18:amd64.
remote: Unpacking libmysqlclient18:amd64 (from .../libmysqlclient18_5.5.27-0ubuntu2_amd64.deb) ...
remote: Selecting previously unselected package php5-mysql.
remote: Unpacking php5-mysql (from .../php5-mysql_5.4.6-1ubuntu1_amd64.deb) ...
remote: Processing triggers for libapache2-mod-php5 ...
remote:  * Reloading web server config
remote:    ...done.
remote: Setting up mysql-common (5.5.27-0ubuntu2) ...
remote: Setting up libmysqlclient18:amd64 (5.5.27-0ubuntu2) ...
remote: Setting up php5-mysql (5.4.6-1ubuntu1) ...
remote: Processing triggers for libc-bin ...
remote: ldconfig deferred processing now taking place
remote: Processing triggers for libapache2-mod-php5 ...
remote:  * Reloading web server config
remote:    ...done.
remote: sudo: unable to resolve host 8cf20f4da877
remote: sudo: unable to resolve host 8cf20f4da877
remote: debconf: unable to initialize frontend: Dialog
remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
remote: debconf: falling back to frontend: Readline
remote: debconf: unable to initialize frontend: Dialog
remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
remote: debconf: falling back to frontend: Readline
remote:
remote: Creating config file /etc/php5/mods-available/mysql.ini with new version
remote: debconf: unable to initialize frontend: Dialog
remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
remote: debconf: falling back to frontend: Readline
remote:
remote: Creating config file /etc/php5/mods-available/mysqli.ini with new version
remote: debconf: unable to initialize frontend: Dialog
remote: debconf: (Dialog frontend will not work on a dumb terminal, an emacs shell buffer, or without a controlling terminal.)
remote: debconf: falling back to frontend: Readline
remote:
remote: Creating config file /etc/php5/mods-available/pdo_mysql.ini with new version
remote:
remote:  ---> App will be restarted, please check its log for more details...
remote:
To git@git.tsuru.io:ingress.git
 * [new branch]      master -> master

Running the application

As you can see, in the deploy output there is a step described as “App will be restarted”. In this step, tsuru will restart your app if it’s running, or start it if it’s not. Now that the app is deployed, you can access it from your browser, getting the IP or host listed in app-list and opening it. For example, in the list below:

$ tsuru app-list
+-------------+-------------------------+---------------------+--------+
| Application | Units State Summary     | Address             | Ready? |
+-------------+-------------------------+---------------------+--------+
| blog        | 1 of 1 units in-service | blog.cloud.tsuru.io | Yes    |
+-------------+-------------------------+---------------------+--------+

Using services

Now that php is running, we can accesss the application in the browser, but we get a database connection error: “Error establishing a database connection”. This error means that we can’t connect to MySQL. That’s because we should not connect to MySQL on localhost, we must use a service. The service workflow can be resumed to two steps:

1. Create a service instance
2. Bind the service instance to the app

But how can I see what services are available? Easy! Use service-list command:

$ tsuru service-list
+----------------+-----------+
| Services       | Instances |
+----------------+-----------+
| mongodb        |           |
| mysql          |           |
+----------------+-----------+

The output from service-list above says that there are two available services: “elastic-search” and “mysql”, and no instances. To create our MySQL instance, we should run the service-add command:

$ tsuru service-add mysql blogsql
Service successfully added.

Now, if we run service-list again, we will see our new service instance in the list:

$ tsuru service-list
+----------------+-----------+
| Services       | Instances |
+----------------+-----------+
| elastic-search |           |
| mysql          | blogsql   |
+----------------+-----------+

To bind the service instance to the application, we use the bind command:

$ tsuru bind blogsql
Instance blogsql is now bound to the app blog.

The following environment variables are now available for use in your app:

- MYSQL_PORT
- MYSQL_PASSWORD
- MYSQL_USER
- MYSQL_HOST
- MYSQL_DATABASE_NAME

For more details, please check the documentation for the service, using service-doc command.

As you can see from bind output, we use environment variables to connect to the MySQL server. Next step would be update the wp-config.php to use these variables to connect in the database:

$ grep getenv wp-config.php
define('DB_NAME', getenv('MYSQL_DATABASE_NAME'));
define('DB_USER', getenv('MYSQL_USER'));
define('DB_PASSWORD', getenv('MYSQL_PASSWORD'));
define('DB_HOST', getenv('MYSQL_HOST'));

You can extend your wordpress installing plugins into your repository. In the example bellow, we are adding the Amazon S3 capability to wordpress, just installing 2 more plugins: Amazon S3 and Cloudfront + Amazon Web Services. It’s the right way to store content files into Tsuru.

$ cd wp-content/plugins/
$ wget http://downloads.wordpress.org/plugin/amazon-web-services.0.1.zip
$ wget http://downloads.wordpress.org/plugin/amazon-s3-and-cloudfront.0.6.1.zip
$ unzip amazon-web-services.0.1.zip
$ unzip amazon-s3-and-cloudfront.0.6.1.zip
$ rm -f amazon-web-services.0.1.zip amazon-s3-and-cloudfront.0.6.1.zip
$ git add amazon-web-services/ amazon-s3-and-cloudfront/

Now you need to add the amazon AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environments support into wp-config.php. You could add these environments right after the WP_DEBUG as bellow:

$ grep -A2 define.*WP_DEBUG  wp-config.php
define('WP_DEBUG', false);
define('AWS_ACCESS_KEY_ID', getenv('AWS_ACCESS_KEY_ID'));
define('AWS_SECRET_ACCESS_KEY', getenv('AWS_SECRET_ACCESS_KEY'));
$ git add wp-config.php
$ git commit -m 'adding plugins for S3'
$ git push tsuru master

Now, just inject the right values for these environments with tsuru env-set as bellow:

$ tsuru env-set AWS_ACCESS_KEY_ID="xxx" AWS_SECRET_ACCESS_KEY="xxxxx" -a blog

It’s done! Now we have a PHP project deployed on tsuru, with S3 support using a MySQL service.

Going further

For more information, you can dig into tsuru docs, or read complete instructions of use for the tsuru command.