After installing a specific version of php-fpm through docker, I went into the container and changed the php-fpm user group www-data to my own erik (because the host uses the same one, which makes debugging easier).
After installation, configuring nginx locally always gave an error:
6239#6239: *1 FastCGI sent in stderr: “Primary script unknown” while reading response header from upstream
I searched for the problem over and over and found nothing.
In the end I discovered that php-fpm inside docker specified the project directory as /var/www, while mine locally was /home/work. So when the local nginx maps to docker’s php for communication, it resolves the specified path, and the two paths are different. php-fpm can’t recognize the path, unless the path specified at install time is the same as the local one.
Once that part was solved, accessing a standalone php file worked fine, but accessing the project framework still failed to resolve.
The error was 12909#12909: *3 FastCGI sent in stderr: “Primary script unknown” while reading response header from upstream
By tracing nginx and then checking the project directory in docker, I found that the local project had been symlinked to the project directory shared with docker, and docker cannot recognize a local symlink. I had to cp the project over instead.
At this point, the project was accessible normally.
Actually, this configuration wasted a lot of time, and I was a bit panicked, my previous train of thought got tangled up.
Generally speaking, php file not found is almost always about an inaccessible directory involving permissions, or the project not existing.
Second, a CGI that can’t resolve involves whether the permission groups of php-fpm and nginx and the project directory match up.
