Using Dokku to Deploy PHP Applications with a "git push" on DigitalOcean

Want a Platform-as-a-Service setup like Heroku on your own $5/month VPS from DigitalOcean? Look no further than Dokku - a set of scripts built on Docker and Heroku’s own buildpacks. After this setup, you’re just one git push away from deploying your app to your own server.

Step 1: Create a new Droplet with Dokku

DigitalOcean has a great guide on how to use the DigitalOcean Dokku Application, so there is no sense in repeating the steps here. Follow the steps in that article, and then come back here. There are issues I ran into after the Dokku setup that are important steps not to skip. So be sure to come back here before trying to deploy your PHP application.

Step 2: Setup Swap Space

DigitalOcean boxes don’t come with any disk swap space configured by default, but Dokku uses some when deploying your apps, so you need to configure some using this guide before your first git push or you may run into errors (I sure did). The guide says Ubuntu 12.04, but it works on 13.04 too, so no worries. Do this and then come back. I’ll wait.

Step 3: Deploy Your App

Although the setup is not fully complete, try and deploy your app now to make sure your dokku setup is working properly. You also need to deploy your app now so you will have a container ready for the next steps.

git remote add dokku
git push dokku master

The ouput of the git push will let you know if your deploy was successful or not. If you have a successful deploy, but get a “502 Bad Gateway” response from Nginx, continue with the steps below.

Step 4: Install the user-env-compile Plugin

Install the user-env-compile plugin. This will allow you to set environment variables on your app that are available to be used at build time. This is important for the next step.

Step 5: Use CHH’s PHP Buildpack

Now that you have the user-env-compile plugin installed and have created your app’s initial container, you can set environment variable configuration values on it. To specify what buildpack you want to use, set the BUILDPACK_URL ENV value.

ssh dokku@<> config:set <app_name> BUILDPACK_URL=

You should see output like this:

-----> Setting config vars and restarting <app_name>
-----> Releasing <app_name> ...
-----> Release complete!
-----> Deploying <app_name> ...
-----> Deploy complete!

NOTE: ANY Heroku buildpack will work, so if you wnat to use another one, you are free to do so, although it is very doubtful you will find a better one for PHP :).

Step 6: Set your Document Root

Now open your composer.json file, and add the extra configuration block to specify your document-root and index-document so the PHP buildpack will know where to serve your files from.

    "require": {
        "php": ">=5.4.0",
        "vlucas/bulletphp": "~1.3.x"
    "extra": {
        "heroku": {
            "framework": "slim",
            "document-root": "web",
            "index-document": "index.php"

Note: The framework key here is slim. This doesn’t match my framework Bullet, but I have to put this in here because this maps to the nginx config file used. So if I don’t specify this here, the buildpack assumes a standard classic PHP setup and will only execute .php files, and not rewrite all requests to the main index.php file like most frameworks (including Bullet) require, causing nginx to throw lots of “404 error” responses.

The configuration key says heroku, but this works for dokku too - remember Dokku basically uses all the same basic things that Heroku does - buildpacks, git based deploys, putting apps in their own sandboxed containers, etc.

Step 7: Install Other Plugins Your App Needs

Custom Domains

You will want the dokku domains plugin so your app can use domains instead of subdomains or ports.

Then add your domain to your your app using:

ssh dokku@<> domains:set <app_name>

MySQL / MariaDB

If your app uses MySQL, install the dokku MariaDB plugin (drop-in MySQL Replacement).

Then create a database for your app using:

ssh dokku@<> mariadb:create <app_name>

This will create a DATABASE_URL environment variable that will be available as a DSN string for your app to use to connect to the database via PDO or other ORM that you may want to use. You can access this in PHP via $_SERVER['DATABASE_URL'].

Other Plugins

If you use Redis, Memcached, or anything else, check the Dokku Plugins page and install whatever you need.

Step 8: Re-Deploy Your App

This time when you deploy your app via git push, it will use the custom buildpack you set in Step 4. You should be able to view your app live on your custom port, subdomain, or domain now, and all should be well.

Now sit back, relax, and enjoy your own mini-Heroku at a fraction of the cost!

Posted on Feb 8, 2014