Getting Started with PHP on Heroku

Introduction

This tutorial will have you deploying a PHP app in minutes.

Hang on for a few more minutes to learn how it all works, so you can make the most out of Heroku.

The tutorial assumes that you have:

• a free Heroku account
• PHP installed
• Composer installed

Set up

In this step you will install the Heroku Toolbelt. This provides you access to the Heroku Command Line utility, as well as git and Foreman, tools you’ll use in later steps.

Download the Heroku Toolbelt

Once installed, you can use the heroku command from your command shell.

Log in using the email address and password you used when creating your Heroku account:

$ heroku login
Enter your Heroku credentials.
Email: dz@example.com
Password:
Authentication successful.

Authenticating is required to allow both the heroku and git commands to operate.

Note that if you’re behind a firewall that requires use of a proxy to connect with external HTTP/HTTPS services, you can set the HTTP_PROXY or HTTPS_PROXY environment variables before running the heroku command.

Prepare the app

In this step, you will prepare a simple application that can be deployed.

Execute the following commands to clone the sample application:

$ git clone https://github.com/heroku/php-getting-started.git
$ cd php-getting-started

You now have a functioning git repository that contains a simple application as well as a composer.json file. Make sure you’ve installed Composer. Heroku uses Composer for dependency management in PHP projects, and the composer.json file indicates to Heroku that your application is written in PHP.

Deploy the app

In this step you will deploy the app to Heroku.

Create an app on Heroku, which prepares Heroku to receive your source code:

$ heroku create
Creating sharp-rain-871... done, stack is cedar-14
http://sharp-rain-871.herokuapp.com/ | https://git.heroku.com/sharp-rain-871.git
Git remote heroku added

When you create an app, a git remote (called heroku) is also created and associated with your local git repository.

Heroku generates a random name (in this case sharp-rain-871) for your app - you can pass a parameter to specify your own, or rename it later with heroku apps:rename.

Now deploy your code:

$ git push heroku master
Initializing repository, done.
Counting objects: 7, done.
Delta compression using up to 4 threads.
Compressing objects: 100% (4/4), done.
Writing objects: 100% (7/7), 1.66 KiB | 0 bytes/s, done.
Total 7 (delta 0), reused 0 (delta 0)

-----> PHP app detected
-----> Setting up runtime environment...
       - PHP 5.5.12
       - Apache 2.4.9
       - Nginx 1.4.6
-----> Installing PHP extensions:
       - opcache (automatic; bundled, using 'ext-opcache.ini')
-----> Installing dependencies...
       Composer version 64ac32fca9e64eb38e50abfadc6eb6f2d0470039 2014-05-24 20:57:50
       Loading composer repositories with package information
       Installing dependencies from lock file
...
         - Installing monolog/monolog (1.9.1)
       Generating optimized autoload files
-----> Building runtime environment...
-----> Discovering process types
       Procfile declares types -> web
-----> Compressing... done, 57.4MB
-----> Launching... done, v3
       http://sharp-rain-871.herokuapp.com/ deployed to Heroku

To git@heroku.com:sharp-rain-871.git
 * [new branch]      master -> master

The application is now deployed. Ensure that at least one instance of the app is running:

$ heroku ps:scale web=1

Now visit the app at the URL generated by its app name. As a handy shortcut, you can open the website as follows:

$ heroku open

View logs

Heroku treats logs as streams of time-ordered events aggregated from the output streams of all your app and Heroku components, providing a single channel for all of the events.

View information about your running app using one of the logging commands, heroku logs:

$ heroku logs --tail
014-05-27T11:03:21.033331+00:00 app[web.1]: Booting on port 28661...
2014-05-27T11:03:21.127050+00:00 app[web.1]: Using Apache2 configuration file 'vendor/heroku/heroku-buildpack-php/conf/apache2/heroku.conf'
2014-05-27T11:03:21.068192+00:00 app[web.1]: Using PHP configuration (php.ini) file 'vendor/heroku/heroku-buildpack-php/conf/php/php.ini'
...
2014-05-27T11:03:23.883157+00:00 heroku[web.1]: State changed from starting to up

Visit your application in the browser again, and you’ll see another log message generated.

2014-05-30T13:18:13.581545+00:00 app[web.1]: [30-May-2014 13:18:13] WARNING: [pool www] child 59 said into stderr: "[2014-05-30 13:18:13] myapp.DEBUG: logging output. [] []"

Logging, then, is simply a matter of directing output to stdout or stderr - Heroku does the work of aggregating this across all the app and system components. View the web/index.php file to see how the Monolog service is configured to write its output to stderr.

Press Control+C to stop streaming the logs.

Define a Procfile

Use a Procfile, a text file in the root directory of your application, to explicitly declare what command should be executed to start your app.

The Procfile in the example app you deployed looks like this:

web: vendor/bin/heroku-php-apache2 web/

This declares a single process type, web, and the command needed to run it. The name web: is important here. It declares that this process type will be attached to the HTTP routing stack of Heroku, and receive web traffic when deployed.

Procfiles can contain additional process types. For example, you might declare one for a background worker process that processes items off of a queue.

Scale the app

Right now, your app is running on a single web dyno. Think of a dyno as a lightweight container that runs the command specified in the Procfile.

You can check how many dynos are running using the ps command:

$ heroku ps
=== web (1X): `vendor/bin/heroku-php-apache2`
web.1: up 2014/05/27 12:03:23 (~ 11m ago)

Having only a single web dyno running will result in the dyno going to sleep after one hour of inactivity. This causes a delay of a few seconds for the first request upon waking. Subsequent requests will perform normally.

To avoid this, you can scale to more than one web dyno. For example:

$ heroku ps:scale web=2

For abuse prevention, scaling the application may require account verification. If your account has not been verified, you will be directed to visit the verification site.

For each application, Heroku provides 750 free dyno-hours. Running your app at 2 dynos would exceed this free, monthly allowance, so scale back:

$ heroku ps:scale web=1

Declare app dependencies

Heroku recognizes an app as PHP by the existence of a composer.json file in the root directory.

The demo app you deployed already has a composer.json, and it looks something like this:

{
  "require" : {
    "silex/silex": "~1.1",
    "monolog/monolog": "~1.7"
  },
  "require-dev": {
    "heroku/heroku-buildpack-php": "*"
  }
}

The composer.json file specifies the dependencies that should be installed with your application. When an app is deployed, Heroku reads this file and installs the appropriate dependencies into the vendor directory.

Your PHP app can then make use of the dependencies after a simple require:

require('../vendor/autoload.php');

Run the following command to install the dependencies, preparing your system for running the app locally:

$ composer update
Loading composer repositories with package information
Updating dependencies (including require-dev)
  - Installing psr/log (1.0.0)
    Loading from cache
...
Writing lock file
Generating autoload files

You should always check composer.json and composer.lock into your git repo. The vendor directory should be included in your .gitignore file.

Push local changes

In this step you’ll learn how to propagate a local change to the application through to Heroku. As an example, you’ll modify the application to add an additional dependency (the Twig template engine) and the code to use it.

Modify composer.json to include a dependency for twig:

  "require" : {
    "silex/silex": "~1.1",
    "monolog/monolog": "~1.7",
    "twig/twig": "~1.0"
  }

As you’ve introduced a new dependency, ensure it’s fetched:

$ composer update

Modify index.php so that it uses Twig to render a template. Do this by first adding some code to register a Twig service provider:

// Register the Twig templating engine
$app->register(new Silex\Provider\TwigServiceProvider(), array(
  'twig.path' => __DIR__.'/../views',
));

Then introduce a new route:

$app->get('/twig/{name}', function ($name) use ($app) {
    return $app['twig']->render('index.twig', array(
        'name' => $name,
    ));
});

When that route is visited, it will pass the name to the Twig renderer, together with the index.twig template.

Now create a views subdirectory to store the templates:

$ mkdir views
$ cd views

Create a file within the views directory, index.twig, which looks something like this:

<p>
  This is a Twig template
</p>
<p>
  Rendering name attribute: <b>{{name}}</b>
</p>

If you get lost making these changes, take a look at the step-2 branch of the sample app.

Now deploy. Almost every deploy to Heroku follows this same pattern.

First, add the modified files to the local git repository. Start by changing back to the root directory of your app, and adding the new files to your local git repository:

$ cd ..
$ git add .

Now commit the changes to the repository:

$ git commit -m "Demo"

Now deploy, just as you did previously:

$ git push heroku master

Finally, check that everything is working:

$ heroku open

Provision add-ons

Add-ons are third-party cloud services that provide out-of-the-box additional services for your application, from persistence through logging to monitoring and more.

By default, Heroku stores 1500 lines of logs from your application. However, it makes the full log stream available as a service - and several add-on providers have written logging services that provide things such as log persistence, search, and email and SMS alerts when certain conditions are met. This tutorial step demonstrates add-ons by installing a logging provider.

Provision the papertrail logging add-on:

$ heroku addons:add papertrail
Adding papertrail on sharp-rain-871... done, v4 (free)
...
Happy logging!
Use `heroku addons:docs papertrail` to view documentation.

To help with abuse prevention, provisioning an add-on may require account verification. If your account has not been verified, you will be directed to visit the verification site.

The add-on is now deployed and configured for your application. You can list add-ons for your app like so:

$ heroku addons

To see this particular add-on in action, visit your application’s Heroku URL a few times. Each visit will generate more log messages, which should now get routed to the papertrail add-on. Visit the papertrail console to see the log messages:

$ heroku addons:open papertrail

A console will open up, showing the latest log events, and providing you with an interface to search and set up alerts:

Start an interactive shell

You can run a command, typically scripts and applications that are part of your app, in a one-off dyno using the heroku run command. It can also be used to launch an interactive PHP shell attached to your local terminal for experimenting in your app’s environment:

$ heroku run "php -a"
Running `php -a` attached to terminal... up, run.8081
Interactive shell

php > echo PHP_VERSION;
5.5.12

If you receive an error, Error connecting to process, then you may need to configure your firewall.

The PHP console has nothing loaded other than the PHP standard library. To quit the PHP shell, type quit.

To get a real feel for how dynos work, you can create another one-off dyno and run the bash command, which opens up a shell on that dyno. You can then execute commands there. Each dyno has its own ephemeral filespace, populated with your app and its dependencies - once the command completes (in this case, bash), the dyno is removed.

$ heroku run bash
Running `bash` attached to terminal... up, run.3052
~ $ ls
Procfile  README.md  composer.json  composer.lock  vendor  views  web
~ $ exit
exit

Don’t forget to type exit to exit the shell and terminate the dyno.

Define config vars

Heroku lets you externalise configuration - storing data such as encryption keys or external resource addresses in config vars.

At runtime, config vars are exposed as environment variables to the application.

Modify index.php so that root route returns the word Hello repeated by the value of the TIMES environment variable:

$app->get('/', function() use($app) {
  $app['monolog']->addDebug('logging output.');
  return str_repeat('Hello', getenv('TIMES'));
});

To set the config var on Heroku, execute the following:

$ heroku config:set TIMES=20

View the config vars that are set using heroku config:

$ heroku config
=== sharp-rain-871 Config Vars
PAPERTRAIL_API_TOKEN: erdKhPeeehIcdfY7ne
TIMES: 20

Deploy your changed application to Heroku to see this in action.

Provision a database

The add-on marketplace has a large number of data stores, from Redis and MongoDB providers, to Postgres and MySQL. In this step you will add a free Heroku Postgres Starter Tier dev database to your app.

Add the database:

$ heroku addons:add heroku-postgresql:hobby-dev
Adding heroku-postgresql:hobby-dev... done, v3 (free)

This creates a database, and sets a DATABASE_URL config var (you can check by running heroku config).

Modify composer.json to include a dependency for a simple PDO service provider, herrera-io/silex-pdo:

  "require" : {
    "silex/silex": "~1.1",
    "monolog/monolog": "~1.7",
    "twig/twig": "~1.0",
    "herrera-io/silex-pdo": "~1.2"
  },

Install the new dependency:

$ composer update

Now modify index.php to extend the app to add a PDO connection:

$dbopts = parse_url(getenv('DATABASE_URL'));
$app->register(new Herrera\Pdo\PdoServiceProvider(),
  array(
    'pdo.dsn' => 'pgsql:dbname='.ltrim($dbopts["path"],'/').';host='.$dbopts["host"],
    'pdo.port' => $dbopts["port"],
    'pdo.username' => $dbopts["user"],
    'pdo.password' => $dbopts["pass"]
  )
);

Note how this code retrieves the DATABASE_URL config var from the environment using getenv(), and extracts information on hostname, database and credentials from that config var using parse_url().

In the same file, add a new handler to query the database:

$app->get('/db/', function() use($app) {
  $st = $app['pdo']->prepare('SELECT name FROM test_table');
  $st->execute();

  $names = array();
  while ($row = $st->fetch(PDO::FETCH_ASSOC)) {
    $app['monolog']->addDebug('Row ' . $row['name']);
    $names[] = $row;
  }

  return $app['twig']->render('database.twig', array(
    'names' => $names
  ));
});

This ensures that when you access your app using the /db route, it will return all rows in the test_table table, and render the results using the database.twig template. Create the template in the views directory:

<p>Got these rows from the database:</p>

<ul>
{% for n in names %}
  <li> {{ n.name }} </li>
{% else %}
  <li>Nameless!</li>
{% endfor %}
</ul>

If you get lost making these changes, take a look at the step-3 branch of the sample app.

Deploy the app modifications to Heroku:

$ git add .
$ git commit -m 'added database access'
$ git push heroku master

If you now access /db you will see Nameless in the output as there is no table in the database. Assuming that you have Postgres installed locally, use the heroku pg:psql command to connect to the database you provisioned earlier, create a table and insert a row:

$ heroku pg:psql
psql (9.3.2, server 9.3.3)
SSL connection (cipher: DHE-RSA-AES256-SHA, bits: 256)
Type "help" for help.
=> create table test_table (id integer, name text);
CREATE TABLE
=> insert into test_table values (1, 'hello database');
INSERT 0 1
=> \q

Now when you access your app’s /db route, you will see something like this:

Got these rows from the database:

* hello database

Read more about Heroku PostgreSQL.

A similar technique can be used to install MongoDB or Redis add-ons.

Next steps

You now know how to deploy an app, change its configuration, view logs, scale, and attach add-ons.

Here’s some recommended reading:

• Read How Heroku Works for a technical overview of the concepts you’ll encounter while writing, configuring, deploying and running applications.
• Read Deploying PHP Apps on Heroku to understand how to take an existing PHP app and deploy it to Heroku.
• Visit the PHP category to learn more about developing and deploying PHP applications.