解决 nginx "Primary script unknown" 出错

查看 nginx的error.log，有以下出错记录：

*1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 192.168.0.114, server: localhost, request: "GET /test.php HTTP/1.1", upstream: "fastcgi://unix:/run/php/php8.1-fpm.sock:", host: "192.168.0.11"

原因是 fastcgi_param 参数配置有问题，nginx默认配置为： fastcgi_param SCRIPT_FILENAME /scripts$fastcgi_script_name;  　　

但是，如果在nginx.conf 中设置了本地的 root 目录，那么需要将 fastcgi_param 参数修改为： fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;

    location ~ \.php$ {
        # root           html;
        # fastcgi_pass   127.0.0.1:9000;
        fastcgi_pass unix:/run/php/php8.1-fpm.sock;
        fastcgi_index  index.php;
        # fastcgi_param  SCRIPT_FILENAME  /scripts$fastcgi_script_name;
        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
        include        fastcgi_params;
    }