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PHP Primary script unknown Solution Summary

  • 2021-12-19 06:25:49
  • OfStack

I believe many people who configure php environment have encountered this annoying problem:

The browser accesses the php file and returns File not found View/var/log/nginx/error. log, with "Primary script unknown", similar to the following: 

2019/01/03 10:24:02 [error] 11931#11931: *260 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream,
client: 1.2.3.4, server: localhost, request: "GET /index.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: www.example.com

There are only two reasons, one is that php-fpm cannot find php file, and the other is that php-fpm does not have permission to read and execute files.

1. File problem not found

The php section of the site configuration file for nginx should look like this: 


# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
  location ~ \.php$ {    #root  The path configuration must be there, and it must be written correctly (don't laugh, it can really be written wrong) 
    root      /usr/share/nginx/html;
    fastcgi_pass  127.0.0.1:9000;
    fastcgi_index index.php;    #SCRIPT_FILENAME Use $document_root Instead of a specific path 
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include    fastcgi_params;
  }

2. Authority issues

It is also the one with the most pits.

1) Process users

user configuration in nginx. conf should be similar to php-fpm. d/www. conf 1, for example, nginx is used, or phpuser is a custom user (another nonsense, this user needs to be built in advance).

nginx. conf: 


user phpuser;
worker_processes auto;

php-fpm. d/www. conf: 


; Unix user/group of processes
; Note: The user is mandatory. If the group is not set, the default user's group
;    will be used.
user = phpuser
group = phpuser

nginx and php-fpm process/listening information: 


root   19107 0.0 0.1 207644 5852 ?    Ss  1 Month 02  0:03 php-fpm: master process (/usr/local/etc/php-fpm.conf)
phpuser 19108 0.0 0.1 207644 7108 ?    S  1 Month 02  0:00 php-fpm: pool www
phpuser 19109 0.0 0.1 207644 7112 ?    S  1 Month 02  0:00 php-fpm: pool www
root   24676 0.0 0.0 56660 1024 ?    Ss  13:08  0:00 nginx: master process /usr/sbin/nginx -c /etc/nginx/nginx.conf
phpuser 24677 0.0 0.7 84680 29976 ?    S  13:08  0:00 nginx: worker process
phpuser 24678 0.0 0.7 84324 29236 ?    S  13:08  0:00 nginx: worker process
tcp    0   0 127.0.0.1:9000     0.0.0.0:*        LISTEN   19107/php-fpm: mast
tcp    0   0 0.0.0.0:80       0.0.0.0:*        LISTEN   24676/nginx: master
tcp6    0   0 :::80          :::*          LISTEN   24676/nginx: master

If nginx is modified, users must also change some directory permissions: 


chown -R phpuser:phpuser /var/log/nginx
chown -R phpuser:phpuser /var/cache/nginx
chown -R phpuser:phpuser /usr/share/nginx/html

There are also/etc/logrotate. d/nginx, create 640 nginx adm lines to be changed: 


create 640 phpuser adm

2) Directory and file permissions

The php file doesn't have to be set to 777, which makes people worry. As long as nginx and php-fpm run, it can be read and written by users, and 1 can be 770.

php file directory and file sample: 


drwxrwx--- 6 phpuser phpuser 4.0K 2019-01-03 13:09 /usr/share/nginx/html
-rwxrwx--- 1 phpuser phpuser 40  2019-01-03 13:09 /usr/share/nginx/html/phpinfo.php

There is a deep hole here, which is likely to be a trick for using other directories to place php files, that is, phpuser should be allowed to access every layer directory of/path/to/phpfiles, and Permission denied will be found if one layer is missing.

In this example, every layer of directories above/usr/share/nginx/html is owned by root and has o+rx, that is, everyone has read and execute permissions (read and execute permissions are fundamental to directory access), so phpuser can access the html directory. 


drwxr-xr-x. 13 root root    155 2018-07-10 15:42 /usr
drwxr-xr-x. 86 root root    4.0K 2018-12-17 07:33 /usr/share/
drwxr-xr-x  4 root root     40 2018-12-17 08:06 /usr/share/nginx/
drwxrwx---  6 phpuser phpuser 4.0K 2019-01-03 13:11 /usr/share/nginx/html/

Test method: 


sudo -u phpuser ls -l /usr/share/nginx/html/

3) SELINUX

nginx/apache Web page file selinux context, if change directory needs to be matched. (Testing on Cenots7+php7.3, static file 404 without selinux context, but php file did not encounter problems and did not delve into it.) 


# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
  location ~ \.php$ {    #root  The path configuration must be there, and it must be written correctly (don't laugh, it can really be written wrong) 
    root      /usr/share/nginx/html;
    fastcgi_pass  127.0.0.1:9000;
    fastcgi_index index.php;    #SCRIPT_FILENAME Use $document_root Instead of a specific path 
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include    fastcgi_params;
  }
0

Configure the selinux context: 


# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
  location ~ \.php$ {    #root  The path configuration must be there, and it must be written correctly (don't laugh, it can really be written wrong) 
    root      /usr/share/nginx/html;
    fastcgi_pass  127.0.0.1:9000;
    fastcgi_index index.php;    #SCRIPT_FILENAME Use $document_root Instead of a specific path 
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include    fastcgi_params;
  }
1

Or simply shut down selinux (you need to restart the server)

/etc/selinux/config: 


# pass the PHP scripts to FastCGI server listening on 127.0.0.1:9000
  location ~ \.php$ {    #root  The path configuration must be there, and it must be written correctly (don't laugh, it can really be written wrong) 
    root      /usr/share/nginx/html;
    fastcgi_pass  127.0.0.1:9000;
    fastcgi_index index.php;    #SCRIPT_FILENAME Use $document_root Instead of a specific path 
    fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
    include    fastcgi_params;
  }
2

3. Finally 


echo "<p align='center'>Good Luck :)</p><?php phpinfo(); ?>" > /usr/share/nginx/html/phpinfo.php

That's all about the ultimate solution for PHP Primary script unknown. Thank you for supporting this site.

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