Why am I having issues deploying Symfony 4 app to Heroku? - php

Question

I'm trying to deploy my Symfony 4 app to Heroku and, obviously, encountering some issues with it.
I first had the "403 Forbidden" error because the document root had not been set in my Procfile.
My answer to that was, after reading other questions and answers I could find around, using any of these:
web: $(composer config bin-dir)/heroku-php-apache2 public/
web: bin/heroku-php-apache2 public/
web: vendor/bin/heroku-php-apache2 public/
web: vendor/bin/heroku-php-apache2 /public/
They all gave back different kinds of "500 Internal Server Error" pages - most of them, saying something along the lines of Request exceeded the limit of 10 internal redirects due to probable configuration error.
Which lead me to think about some issue in my public/.htaccess file instead.
With comments removed, it looks like this:
# Use the front controller as index file. It serves as a fallback solution when
# every other rewrite/redirect fails (e.g. in an aliased environment without
# mod_rewrite). Additionally, this reduces the matching process for the
# start page (path "/") because otherwise Apache will apply the rewriting rules
# to each configured DirectoryIndex file (e.g. index.php, index.html, index.pl).
DirectoryIndex app.php
# By default, Apache does not evaluate symbolic links if you did not enable this
# feature in your server configuration. Uncomment the following line if you
# install assets as symlinks or if you experience problems related to symlinks
# when compiling LESS/Sass/CoffeScript assets.
# Options FollowSymlinks
# Disabling MultiViews prevents unwanted negotiation, e.g. "/app" should not resolve
# to the front controller "/app.php" but be rewritten to "/app.php/app".
<IfModule mod_negotiation.c>
Options -MultiViews
</IfModule>
<IfModule mod_rewrite.c>
RewriteEngine On
# Determine the RewriteBase automatically and set it as environment variable.
# If you are using Apache aliases to do mass virtual hosting or installed the
# project in a subdirectory, the base path will be prepended to allow proper
# resolution of the app.php file and to redirect to the correct URI. It will
# work in environments without path prefix as well, providing a safe, one-size
# fits all solution. But as you do not need it in this case, you can comment
# the following 2 lines to eliminate the overhead.
RewriteCond %{REQUEST_URI}::$1 ^(/.+)/(.*)::\2$
RewriteRule ^(.*) - [E=BASE:%1]
# Sets the HTTP_AUTHORIZATION header removed by Apache
RewriteCond %{HTTP:Authorization} .
RewriteRule ^ - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
# Redirect to URI without front controller to prevent duplicate content
# (with and without `/app.php`). Only do this redirect on the initial
# rewrite by Apache and not on subsequent cycles. Otherwise we would get an
# endless redirect loop (request -> rewrite to front controller ->
# redirect -> request -> ...).
# So in case you get a "too many redirects" error or you always get redirected
# to the start page because your Apache does not expose the REDIRECT_STATUS
# environment variable, you have 2 choices:
# - disable this feature by commenting the following 2 lines or
# - use Apache >= 2.3.9 and replace all L flags by END flags and remove the
# following RewriteCond (best solution)
RewriteCond %{ENV:REDIRECT_STATUS} ^$
RewriteRule ^app\.php(?:/(.*)|$) %{ENV:BASE}/$1 [R=301,L]
# If the requested filename exists, simply serve it.
# We only want to let Apache serve files and not directories.
RewriteCond %{REQUEST_FILENAME} -f
RewriteRule ^ - [L]
# Rewrite all other queries to the front controller.
RewriteRule ^ %{ENV:BASE}/app.php [L]
</IfModule>
<IfModule !mod_rewrite.c>
<IfModule mod_alias.c>
# When mod_rewrite is not available, we instruct a temporary redirect of
# the start page to the front controller explicitly so that the website
# and the generated links can still be used.
RedirectMatch 302 ^/$ /app.php/
# RedirectTemp cannot be used instead
</IfModule>
</IfModule>
Which is indeed weird as I have no public/app.php file - however, swapping that for index.php doesn't seem to fix things either.
I really don't know what else to try, help would be much appreciated.

Answer 1

In my case is I did not add the route "/". Symfony load default page in local environment without that route, but in heroku we need to add it!
I show my code for your reference:
class DefaultController extends AbstractController
{
/**
* #Route("/", name="default")
*/
public function ping()
{
return $this->json([
'message' => 'pong'
]);
}
}

Answer 2

In case anyone else stumbles upon this trying to deploy a Symfony / Symfony 4 app, these are the steps I had to take to solve the issue:
My .htaccess file was outdated and still referenced the old Symfony 3 app.php. What I had to do was delete it and get the new one via composer require symfony/apache-pack
At this point, I still got a 500 Error and the Heroku logs weren't saying anything helpful. That's because Heroku requires you to log things to php://stderr to have them properly logged in the CLI and web interface. As such, I had to modify my config/packages/prod/monolog.yaml file to have the nested handler be like this: path: "php://stderr"
In my case, the second issue turned out being I'd forgotten to run node_modules/.bin/encore production in my postinstall script - but just redirecting logging to php://stderr should point anyone in the right direction.