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How to Deploy a Symfony Application

Deploying a Symfony application can be a complex and varied task depending on the setup and the requirements of your application. This article is not a step-by-step guide, but is a general list of the most common requirements and ideas for deployment.

Symfony Deployment Basics

The typical steps taken while deploying a Symfony application include:

Upload your code to the production server;
Install your vendor dependencies (typically done via Composer and may be done before uploading);
Running database migrations or similar tasks to update any changed data structures;
Clearing (and optionally, warming up) your cache.

A deployment may also include other tasks, such as:

Tagging a particular version of your code as a release in your source control repository;
Creating a temporary staging area to build your updated setup "offline";
Running any tests available to ensure code and/or server stability;
Removal of any unnecessary files from the public/ directory to keep your production environment clean;
Clearing of external cache systems (like Memcached or Redis).

How to Deploy a Symfony Application

There are several ways you can deploy a Symfony application. Start with a few basic deployment strategies and build up from there.

Basic File Transfer

The most basic way of deploying an application is copying the files manually via FTP/SCP (or similar method). This has its disadvantages as you lack control over the system as the upgrade progresses. This method also requires you to take some manual steps after transferring the files (see Common Deployment Tasks).

Using Source Control

If you're using source control (e.g. Git or SVN), you can simplify by having your live installation also be a copy of your repository. When you're ready to upgrade, fetch the latest updates from your source control system. When using Git, a common approach is to create a tag for each release and check out the appropriate tag on deployment (see Git Tagging).

This makes updating your files easier, but you still need to worry about manually taking other steps (see Common Deployment Tasks).

Using Platforms as a Service

Using a Platform as a Service (PaaS) can be a great way to deploy your Symfony app quickly. There are many PaaS, but we recommend Platform.sh as it provides a dedicated Symfony integration and help fund the Symfony development.

Using Build Scripts and other Tools

There are also tools to help ease the pain of deployment. Some of them have been specifically tailored to the requirements of Symfony.

Deployer: This is another native PHP rewrite of Capistrano, with some ready recipes for Symfony.
Ansistrano: An Ansible role that allows you to configure a powerful deploy via YAML files.
Magallanes: This Capistrano-like deployment tool is built in PHP, and may be easier for PHP developers to extend for their needs.
Fabric: This Python-based library provides a basic suite of operations for executing local or remote shell commands and uploading/downloading files.
Capistrano with Symfony plugin: Capistrano is a remote server automation and deployment tool written in Ruby. Symfony plugin is a plugin to ease Symfony related tasks, inspired by Capifony (which works only with Capistrano 2).

Common Deployment Tasks

Before and after deploying your actual source code, there are a number of common things you'll need to do:

A) Check Requirements

There are some :ref:`technical requirements for running Symfony applications <symfony-tech-requirements>`. In your development machine, the recommended way to check these requirements is to use Symfony CLI. However, in your production server you might prefer to not install the Symfony CLI tool. In those cases, install this other package in your application:

$ composer require symfony/requirements-checker

Then, make sure that the checker is included in your Composer scripts:

{
    "...": "...",

    "scripts": {
        "auto-scripts": {
            "vendor/bin/requirements-checker": "php-script",
            "...": "..."
        },

        "...": "..."
    }
}

B) Configure your Environment Variables

Most Symfony applications read their configuration from environment variables. While developing locally, you'll usually store these in .env and .env.local (for local overrides). On production, you have two options:

Create "real" environment variables. How you set environment variables, depends on your setup: they can be set at the command line, in your Nginx configuration, or via other methods provided by your hosting service;
Or, create a .env.local file like your local development.

There is no significant advantage to either of the two options: use whatever is most natural in your hosting environment.

Tip

You might not want your application to process the .env.* files on every request. You can generate an optimized .env.local.php which overrides all other configuration files:

$ composer dump-env prod

The generated file will contain all the configuration stored in .env. If you want to rely only on environment variables, generate one without any values using:

$ composer dump-env prod --empty

C) Install/Update your Vendors

Your vendors can be updated before transferring your source code (i.e. update the vendor/ directory, then transfer that with your source code) or afterwards on the server. Either way, update your vendors as you normally do:

$ composer install --no-dev --optimize-autoloader

Tip

The --optimize-autoloader flag improves Composer's autoloader performance significantly by building a "class map". The --no-dev flag ensures that development packages are not installed in the production environment.

Caution!

If you get a "class not found" error during this step, you may need to run export APP_ENV=prod (or export SYMFONY_ENV=prod if you're not using :ref:`Symfony Flex <symfony-flex>`) before running this command so that the post-install-cmd scripts run in the prod environment.

D) Clear your Symfony Cache

Make sure you clear and warm-up your Symfony cache:

$ APP_ENV=prod APP_DEBUG=0 php bin/console cache:clear

E) Other Things!

There may be lots of other things that you need to do, depending on your setup:

Running any database migrations
Clearing your APCu cache
Add/edit CRON jobs
:ref:`Building and minifying your assets <how-do-i-deploy-my-encore-assets>` with Webpack Encore
Pushing assets to a CDN
On a shared hosting platform using the Apache web server, you may need to install the :ref:`symfony/apache-pack package <web-server-apache-mod-php>`
...

Application Lifecycle: Continuous Integration, QA, etc.

While this article covers the technical details of deploying, the full lifecycle of taking code from development up to production may have more steps: deploying to staging, QA (Quality Assurance), running tests, etc.

The use of staging, testing, QA, continuous integration, database migrations and the capability to roll back in case of failure are all strongly advised. There are simple and more complex tools and one can make the deployment as easy (or sophisticated) as your environment requires.

Don't forget that deploying your application also involves updating any dependency (typically via Composer), migrating your database, clearing your cache and other potential things like pushing assets to a CDN (see Common Deployment Tasks).

Troubleshooting

Deployments not Using the `composer.json` File

The :ref:`project root directory <configuration-kernel-project-directory>` (whose value is used via the kernel.project_dir parameter and the :method:`Symfony\\Component\\HttpKernel\\Kernel::getProjectDir` method) is calculated automatically by Symfony as the directory where the main composer.json file is stored.

In deployments not using the composer.json file, you'll need to override the :method:`Symfony\\Component\\HttpKernel\\Kernel::getProjectDir` method :ref:`as explained in this section <configuration-kernel-project-directory>`.

Learn More

.. toctree::
    :maxdepth: 1

    deployment/proxies