Hey there! We've found the following might help you get unblocked faster:

• 🧵 502 Bad Gateway Error

• 🧵 nginx with php-fpm sometimes get 502 error

• 🧵 502 bad gateway

• 🧵 NGINX 502 Bad Gateway

If you find the answer from one of these, please let us know by solving the thread!

Heyy, in your PHP/Nginx Railway setup, update your nginx.conf to use this: fastcgi_pass 127.0.0.1:9000; not a socket path.

Uhmm, also in your entrypoint.sh, make sure you start both services like this:

php-fpm &

nginx -g 'daemon off;'

this combo should fix it. lmk if it still acts up!!.

Hey idlegea21, Thank you so much! Your suggestions worked perfectly. Changing the fastcgi_pass to 127.0.0.1:9000 and updating the service startup commands in the entrypoint.sh script fixed the 502 error instantly. I was stuck on this for a while, so I really appreciate your help. Accepting the solution now. Thanks again!

@masterguarin, I am happy it helped. feel free to reach out anytime you hit any other roadblocks. happy to helpp!

Hi @idlegea21, thank you again for your help. After applying all the recommended fixes for Nginx and PHP-FPM, the deployment is now successful, but I'm getting a final runtime error when the script tries to connect to the database: Fatal error: Uncaught mysqli_sql_exception: No such file or directory in /var/www/html/login.php:20 The stack trace shows that the mysqli constructor is being called with empty strings for the host and user: mysqli->__construct('', '', ...) This proves that the PHP script is still unable to read the environment variables (like MYSQLHOST) using getenv(), even with a www.conf file that includes clear_env = no. Is there a specific or non-standard configuration required on Railway to correctly pass the service variables into a PHP-FPM process running inside the official php:8.2-fpm container? It seems the environment variables are not being inherited by the FPM worker pool. Any insight you can provide would be greatly appreciated. Thank you.

in your www.conf, set: clear_env = no

Also, make sure that entrypoint.sh starts PHP-FPM like this:

php-fpm -y /usr/local/etc/php-fpm.conf -R &
nginx -g 'daemon off;'

laslty, double check and confirm that railway is injecting the env vars by dumping them in login.php: var_dump(getenv('MYSQLHOST'));

if it's empty, lmk.

Hi @idlegea21, Thank you for the detailed instructions. I have implemented your latest suggestions exactly. My entrypoint.sh now uses the specific php-fpm -y /usr/local/etc/php-fpm.conf -R & command. The deployment is successful, but I am still facing the same root problem. The application fails with the following fatal error: Uncaught mysqli_sql_exception: No such file or directory The stack trace confirms that the environment variables are still not being passed to the script, as the mysqli constructor is being called with empty strings for the host and user: mysqli->__construct('', '', Object(SensitiveParameterValue), '', 0) This proves that getenv('MYSQLHOST') is returning null, even with all the FPM configurations (`clear_env = no`) in place. At this point, it seems to be a platform-level issue with how variables are being injected into the php:8.2-fpm container environment. Could you please investigate further? I can provide a link to the repository if needed. Thank you for your continued help.

Before we try further debugging options,
can you check the “Variables” tab in your backend service to make sure the env vars like MYSQLHOST, MYSQLUSER, etc. are set and properly linked to the correct database service?

Hey @idlegea21, You were absolutely right! That was the final piece of the puzzle. The database service wasn't linked, so the environment variables were never being injected into the application service. As soon as I added the variable references as you suggested, everything started working perfectly. Thank you so much for your patience and for guiding me to the solution. I was stuck on this for a long time, and your help was invaluable. The issue is now completely resolved. Accepting the solution now. Thanks again!

I am Happy it helped.