Caddy not supported in latest Shlink versions? (Cannot serve Shlink at all and add to app.shlink.io)

[bonarae]

Shlink version

5.1.5

PHP version

8.5.9

How do you serve Shlink

Other (explain in summary)

Database engine

MySQL

Database version

8.0.46

Current behavior

Currently, I am configuring Shlink 5.1.5 to run on Caddy 2.11.4 and PHP 8.5.9. Up to the auto-config step on the CLI, it succeeds; however, once I get to serve Shlink from my functional Caddy server, it fails with either HTTP 500 (majority of the time, with php_fastcgi left as default values) or HTTP 404 (with the try_files and index directives copied from the Nginx section of Shlink documentation). I searched far and wide on possible causes, but I cannot find a root cause just yet. PHP-FPM is functioning well in my case (however, its sibling subdomains on Caddy run PHP 8.3, while this one runs PHP 8.5).

I cannot decouple the other functional websites (they all reside as different subdomains on one IP address and one domain) from Caddy, so I cannot use RoadRunner just for Shlink.

Expected behavior

Shlink is running on the server and can be added to app.shlink.io.

Minimum steps to reproduce

1. Install shlink from dist file on GitHub
2. Unzip the zip file and move it to its desired home at /var/www/html
3. Set ownership permissions on the desired home directory
4. Configure the subdomain on /etc/caddy/Caddyfile with the default php_fastcgi parameters
5. Restart Caddy to reflect the changes on the Caddyfile

Configuration for the Shlink instance/subdomain from the functional Caddyfile:

SUBDOMAIN {
    root * /var/www/html/shlink/public
    file_server

# This commented section returns HTTP 404
#    @phpFiles path *.php
#    reverse_proxy @phpFiles unix//run/php/php8.5-fpm.sock {
#       transport fastcgi {
#               split ^(.+\.php)(/.+)$
#       }
#    }

# This section below returns HTTP 500
   php_fastcgi unix//run/php/php8.5-fpm.sock {
        index index.php
        try_files $uri $uri/ /index.php$is_args$args
   }
}

[acelaya]

I have never used Caddy, so it's hard for me to help, but a few things I would try first.

• Have you checked caddy's logs to see what is happening when a 500 error is returned?
• When you say it doesn't work with latest version, do you mean it used to work with previous ones?

I cannot decouple the other functional websites (they all reside as different subdomains on one IP address and one domain) from Caddy, so I cannot use RoadRunner just for Shlink.

I don't fully understand what you mean by this.

[bonarae]

• I tried checking Caddy's logs but I cannot see why the 500 error occurs there for that specific subdomain. I will do further investigations in the coming days.

• There is currently no documentation for Caddy as a traditional web server option for Shlink. I am not sure if other users have successfully implemented Shlink on a Caddy-based server.

• For RoadRunner, it is currently not considered as an option at this time for the other websites utilizing the said webserver containing the specific issue.

[acelaya]

Maybe you can check Shlink logs just in case it has nothing to do specifically with Caddy and we are chasing a red herring.

I still don't understand the problem with using RoadRunner. What do other websites have to do in this?