Getting Started with Symfony and Dokku

2019-02-18 9-minute read

This is the first in a series of posts on integrating Dokku and Symfony and will cover setting up a barebones Symfony app and get it running on Dokku.

A PaaS of Our Own

In a previous post (A PaaS of Our Own: Dokku) we walked though installing Dokku using DigitalOcean’s One-Click Installer and configuring it. This series will build off the work we did in that post.

Barebones Symfony

Before getting creative, we want to just get the most barebones of Symfony applications running. No database, no Encore, just a single controller with two routes and two views.

Operating System

All of the commands, unless otherwise stated, are run on our local computer. I am using a Mac (macOS 10.14 Mojave), though everything should still run fine on Linux. I honestly don’t know how to set this up on Windows.

Creating the Project

To get started, let’s create a new Symfony project called sf-demo.

composer create-project symfony/website-skeleton sf-demo

# ... a whole bunch of installing

cd sf-demo

First Thing: Source Control


Tip 23: Always Use Source Code Control—Always.

Even if you are a single-person team on a one-week project. Even if it’s a “throw-away” prototype. Even if the stuff you’re working on isn’t source code. Make sure that everything is under source control – documentation, phone number lists, memos to vendors, makefiles, build and release procedure, that little shell script that burns the CD master—everything.

— The Pragmatic Programmer, Hunt / Thomas

Before we do anything else, we need to set up out git repository. Not only will we need to git to push our application to Dokku later, it is just a smart thing to do.

git init

# Initialized empty Git repository in /Users/dev88/Projects/sf-demo/.git/

git add .
git commit -m 'Initial Commit'

Just a Homepage

For our barebones app we are going to add a home page and a “more information” page, with both pages being handled by a single Home controller.

Start Our Working Branch

Branching Out

Before we work on a feature or fix bugs, we will create a git branch for our work and then merge that code back into our master branch when we are done.

This is a good practice to be in and works well with both GitLab Flow and GitHub Flow.

To start up a new branch for building our homepage, we run the following commands:

git checkout -b homepage

This creates a new homepage branch and then switches to the new branch.


In this series I will be using the git command for working with our repository. There are a lot of good git GUI apps that you can use if you are not a fan of the command line. On macOS I like Fork (free) and Tower (paid) (and use both regularly).

makeing a Controller

The website-skeleton project we created includes the Symfony MakerBundle that we can use to create a new controller.

bin/console Alias

I have set up sf as an alias for bin/console to save a lot of typing. You can create the same alias by running alias sf="bin/console". To make the alias permanent, need to add that command in your .bashrc or .zshrc.

$ sf make:controller

Enter HomeController as the name for your controller class when prompted. Once the controller is created, we can edit the contents of src/Controller/HomeController.php to be the following:


namespace App\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
use Symfony\Component\Routing\Annotation\Route;

class HomeController extends AbstractController
     * @Route("/", name="home")
    public function index()
        return $this->render('home/index.html.twig');

     * @Route("/more", name="more_info")
    public function more()
        return $this->render('home/more.html.twig');

Twig Templates

The MakerBundler also created the file templates/home/index.html.twig. Update the contents of this file to be:

{% extends 'base.html.twig' %}

{% block title %}Hello Dokku!{% endblock %}

{% block body %}
    <h1>Hello Dokku</h1>

        <a href="{{ path('more_info') }}">
            More information
{% endblock %}

Finally, create a new file templates/home/more.html.twig and make its contents:

{% extends 'base.html.twig' %}

{% block title %}More Information{% endblock %}

{% block body %}
    <h1>More Information</h1>

    <p>This is some more information.</p>

        <a href="{{ path('home') }}">
            Back Home
{% endblock %}

Test Our Pages

We can now test are two pages by starting up a web server:

sf server:run

Go to http://localhost:8000 and we should see our “Hello Dokku” title, and a working link to the “More information” page (which should link back to the homepage). Once you have checked and made sure everything works, you can kill the server with ^C (control-C).

run vs. start

The Symfony documentation instructs you to use server:start and then run server:stop when you are done. The benefit to this is that the server is run in the background and you can keep using the console. server:run blocks the console and you see all of the logging as you use your site.

I have problems with server:start, and I will admit that its something on my computer. If server:start works for you, feel free to use it. For now, I have to use server:run.

Commit and Merge Our Changes

If everything looks good, then you should commit your changes to the repository:

git add .
git commit -m 'Add home and more info pages'

and then merge our changes into master and remove the homepage branch:

git checkout master
git merge homepage
git branch -D homepage

Dokku Prep

A Big Thank You

This article by Matt Brunt was a huge help in figuring this out. A giant “thank you” to Matt for the groundwork.

Before we can push our Symfony app to Dokku, we need to get Dokku ready.

Local Dokku Client

Before we go any further, set up the Dokku Client so you do not have to SSH into the server to run all of the commands for app setup.

To get the client to talk to your server you either need to set the DOKKU_HOST environment variable or be in a git repository with a remote named dokku. We are going to set the DOKKU_HOST environment variable the first time we run it here so that both the app and the remote will get created.

Server Name

My server is - use whatever domain name (or IP address) you have configured for your Dokku server. dokku apps:create sf-demo
   -----> Dokku remote added at called dokku
   -----> Application name is sf-demo
   -----> Creating sf-demo... done

Then we can check our git remotes and make sure the Dokku has been added:

git remote -v
   dokku (fetch)
   dokku (push)

Now our server is set up, we need to prepare our app for deployment.

Nginx Configuration

To set up Nginx to run Symonfy’s rewrite rules, we add a nginx.conf file to the root our app with the following content:

location / {
    # try to serve file directly, fallback to rewrite
    try_files $uri @rewriteapp;

location @rewriteapp {
    # rewrite all to index.php
    rewrite ^(.*)$ /index.php/$1 last;

location ~ ^/index\.php(/|$) {
    try_files @heroku-fcgi @heroku-fcgi;

Add the Procfile

We also need to create a file named Procfile in the root of our app. This file will tell Dokku to use the nginx.conf file.

web: $(composer config bin-dir)/heroku-php-nginx -C nginx.conf public

Setting Environment Variables

Finally we set the environment variables Symfony needs:

dokku config:set APP_ENV=prod
dokku config:set APP_SECRET=$(head /dev/urandom | LC_ALL=C tr -dc A-Za-z0-9 | head -c 32)


Everything is now ready and we can push our application up to Dokku:

git push dokku master

(Maybe) Things Go Horribly Wrong

When I did this, I got the following:

!     ERROR: Failed to download minimal PHP for bootstrapping!
!     This is most likely a temporary internal error. If the problem
!     persists, make sure that you are not running a custom or forked
!     version of the Heroku PHP buildpack which may need updating.
! [remote rejected] master -> master (pre-receive hook declined)
error: failed to push some refs to ''

I had to log into my server and run an upgrade (there commands are all on the server):

sudo apt-get update
sudo apt-get upgrade

The culprit was needing a newer version of Herokuish. Once that was updated, everything worked. Once the upgrade completed, I could push my app to Dokku.

And Possibly More Errors

When I tried to do apt-get update, I received an error about not having the proper GPG key for the repository that handles Dokku. To fix this, I followed the manual install instructions for Dokku’s page. Specifically the following command:

curl -L | sudo apt-key add -

After that command, I could apt-get update and apt-get upgrade.

Adding HTTPS

You should now be able to visit your app at (replace with whatever your domain is). However, we really want that http to be https. To do that we can run:

dokku letsencrypt sf-demo

Let that command run and then refresh your site. It should automatically forward you the https version.

What is Available on the Server?

When building new features, we may need specific PHP extensions installed. To find out what is already installed by the PHP buildpack we are using, we can run the following command:

dokku run 'php -i'

This will dump the PHP configuration and we can check installed extensions, server and environment variables, and all other PHP configuration values.


Currently, our app is logging its errors to var/logs/prod.log. This is fine, however, those logs will get destroyed during each deploy when our app’s container gets rebuilt. There are two ways to handle this:

  1. Mounting persistent storage to our app and writing the logs to there. We will cover mounting persistent storage for file uploads in a later part of this series.
  2. Use a log management provider like Papertrail or Loggly.
  3. If you only care about errors, use a error tracking service such as Rollbar, Bugsnag, or anything supported by Monolog.

For this tutorial, we will just be leaving the logs in var/logs/ and not worrying about them being deleted on each deployment.


We should now have a barebones Symfony up and running on our Dokku server, it should be served over HTTPS, and we are ready to flesh it out.

What Next?

Now that we have a basic Symfony site up and running we can start adding features to experiment with getting them working on Dokku.

In the next post in this series, add a some style to our site with Encore and Bootstrap.

Or start experimenting on your own. I have confidence in you.

Posts in this Series