I get FastCGI "Primary script unknown" error in a NGINX / PHP-FPM containers situation-CodePudding

Context

I've got these two docker containers connected to a network:

php:8-fpm-alpine with my web app, exposing port 9000.
nginx:alpine serving the app.

Both containers have access to a local directory containing the app files.

My NGINX configuration:

server {
    listen 80;
    index index.php index.html;
    error_log  /var/log/nginx/error.log;
    access_log /var/log/nginx/access.log;
    root /usr/share/nginx/html;

    location ~ \.php$ {
        try_files $uri =404;
        fastcgi_split_path_info ^(. \.php)(/. )$;
        fastcgi_pass app:9000;
        fastcgi_index index.php;
        include fastcgi_params;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        fastcgi_param PATH_INFO $fastcgi_path_info;
    }

    location / {
        try_files $uri $uri/ /index.php?$query_string;
        gzip_static on;
    }
}

Problem

When trying to access the site, the browser shows "File not found.".

NGINX container logs:

FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream

PHP-FPM container logs:

"GET /index.php" 404

Things I've checked

App is running.
root in NGINX config actually points to where the app files are.
App directory, inside the app container, has at least public read and execute rights all the way through, which should rule out access issues... right?
There is no other container in the network blocking port 9000.

Could you please point me in some direction? I'm lost.

CodePudding user response：

The NGINX container can see that the file exists at /usr/share/nginx/html/index.php otherwise the try_files statement would be generating the 404 response rather than PHP-FPM.

So the PHP-FPM container has received the request with SCRIPT_FILENAME set to /usr/share/nginx/html/index.php but PHP cannot see the file using that pathname.

As your comment confirms, this is a discrepancy in the pathname routes between the two containers.