added initial php installation guide

docs/php.md

@@ -0,0 +1,62 @@
+# PHP
+An easily integratable language for dynamic HTML with read/write file access possible on the server side.
+
+# Installation
+As always, we're assuming Debian + Nginx for this.
+
+```sh
+apt update
+apt install php php-fpm
+```
+`php-fpm` should automatically enable it's service.
+Verify via `systemctl status php7.3-fpm.service`
+
+# Setup
+Check whether you want to use a TCP connection or a UNIX socket for php connections.
+The default and recommended way is TCP/IP.
+
+## TCP/IP
+You can edit the IP and port of the connection in `/etc/php/7.3/fpm/pool.d/www.conf`
+The default is:
+```
+listen = 127.0.0.1:9000
+```
+
+## Socket
+For socket, use:
+```
+listen = run/php/php7.3-fpm.sock
+```
+
+## Nginx
+To enable nginx to talk to php add the following to your website config:
+```nginx
+location ~\.php${
+	include snippets/fastcgi-php.conf
+	fastcgi_pass 127.0.0.1:9000;
+}
+```
+replace TCP/IP address with the appropriate socket file if that's your preferred setup.
+
+Create a file in the root dir for your website (so probably somwhere in `/var/www/`) ending in `.php` with the content:
+```php
+<?php
+	phpinfo();
+```
+
+And visit `example.com/file.php` to see whether it worked.
+You should get a screen with a lot of information about your php installation.
+
+## File writing permissions
+Per default PHP is unable to read or write to your server drive.
+It is best for this to re-own any directories where php will be writing to to the user and group `www-data`.
+Thus a
+```sh
+chown -R www-data:www-data <dir>
+chmod -R 744 <dir>
+```
+should be a good starting-off point.
+Files only need to have permissions of `644` of course so maybe change that as well.
+
+# Learning PHP
+If you're completely new to php [w3schools' course](https://www.w3schools.com/php) is probably a good starting point.

index.md

@@ -14,6 +14,7 @@ Happy to accept pull requests for new topics!
 - [neomutt](docs/neomutt.md) highly customizable TUI email client
 - [rainloop](docs/rainloop.md) webbased email client
 - [server](docs/ServerSetup.md) short guide for hosting a server
+- [php](docs/php.md) short guide for getting php up and running with nginx
 
 # Admin