I have been doing some experiments with shopping cart systems, and was trying to run them on podman for some “quick” testing. (I’m not much of a container expert, but I don’t have a php setup on my workstation right now, so this seemed like a good time to become one)

Now, OpenCart installation instructions are super manual but that shouldn’t be too hard right?

Well, after a bit of faffing around, looking for an nginx+php-fpm container ready to go, I just fell back and tried:

$ podman run -p 8081:80 -d -v ./opencart-4.0.2.1/upload:/var/www/html php:8-apache

This runs ok, but you’ll instantly get problems trying to access it:

Warning: mkdir(): Permission denied in /var/www/html/system/storage/vendor/twig/twig/src/Cache/FilesystemCache.php on line 50
Warning: file_put_contents(/var/www/html/system/storage/logs/error.log): Failed to open stream: Permission denied in /var/www/html/system/library/log.php on line 34
Warning: file_put_contents(/var/www/html/system/storage/logs/error.log): Failed to open stream: Permission denied in /var/www/html/system/library/log.php on line 34RuntimeException: Unable to create the cache directory (/var/www/html/system/storage/cache/template/c3). in /var/www/html/system/storage/vendor/twig/twig/src/Cache/FilesystemCache.php on line 53

Ok… you are clever and wise, and have been around computers. You understand, in your bones, that podman’s rootless containers means that “apache” is really running as your normal user id, but thinks it has another id inside the container. You do a lot of reading about “podman unshare” but, you really don’t give a shit what fucking UID is being used inside the php apache container?! You finally find what sounds like the right solution, which sounds exactly right, but… not… quite?

$ podman run -p 8082:80 -d --userns=keep-id -v ./opencart-4.0.2.1/upload:/var/www/html php:8-apache
0e726377f1ecdf7120cdd74f9c9b89b424eba6602c01c167440da91e7069685a

$ podman logs -l
AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.0.2.100. Set the 'ServerName' directive globally to suppress this message
(13)Permission denied: AH00072: make_sock: could not bind to address [::]:80
(13)Permission denied: AH00072: make_sock: could not bind to address 0.0.0.0:80
no listening sockets available, shutting down
AH00015: Unable to open logs

Ok, this is because apache runs as root to bind port 80 inside the container, even though you’re always going to map it from the outside anyway, that sucks. Ok, one more bit of magic right? We can just tell the container that it’s allowed to bind to low ports!

podman run -p 8083:80 -d --userns=keep-id --sysctl net.ipv4.ip_unprivileged_port_start=0 -v ./opencart-4.0.2.1/upload:/var/www/html php:8-apache

And you finally get the OpenCart installation page at http://localhost:8083 None of this addresses the rest of the installation, like “removing the install folder once you’re done” and “configure mysql…”