MythWeb on Nginx
Incomplete, needs to be expanded. Please help to fill the gaps or discuss the issue on the talk page
Contents
TODO
- work in progress - stuarta
- Perl Backend
Intro
MythWeb provides a web interface for scheduling and managing recordings from a web browser located on any machine, with new features being added such as remote control.
An Apache server can use a lot of memory, especially for a system where the number of users of the server can be measured on one hand...essentially private. Nginx(pronounced N-Gen-X), is a lightweight, high-performance Web server/reverse proxy.
When trying to understand how nginx does things, it's important to remember that it is a proxy first and a web server second. It just happens to be a blindingly fast web server :)
It is for this reason that you have to install a php backend server as well as a perl backend server to handle the dynamic generation of content.
Installation
Your distribution should have a package for nginx. It is probably woefully out of date. Do yourself a favour and go and get the packages provided at nginx.org [[1]]
The default HTML directory for the nginx packages is /usr/share/nginx/html, whereas a package of MythWeb goes to the Apache directory.../var/www/html/. You can create a symbolic link, or just have nginx root to the same directory as Apache...a good move if you aren't sure you are going to commit to an alternate web server.
So, we'll assume the root is /var/www/html and that the mythweb directory is right off the root.
PHP Backend
Fast-CGI for PHP
Unlike Apache, Nginx doesn't have PHP support built in, and it must be configured for it. The old way was to use fast-cgi. If you are using nginx, you are trying to get performance and scalability. Forget FastCGI and install php-fpm. If you really have trouble finding php fpm then these instructions should also work for fastcgi.
PHP FPM
Ubuntu/Debian have php fpm packages available by default.
apt-get install php5-fpm
This installs a php fpm instance and the default configuration out of the box has it listening on 127.0.0.1:9000
I'd recommend upping the memory limit for php. Edit /etc/php5/fpm/pool.d/www.conf and modify the following
php_admin_value[memory_limit] = 64M
and "reload" php5-fpm.
Perl Backend
Incomplete, needs to be expanded. Please help to fill the gaps or discuss the issue on the talk page
Configuration
Unlike Apache, Nginx does not support .htaccess files, so all configuration must go in the nginx configuration. Of course, for convenience, nginx is defaultly set up to include all files on a conf.d directory, so you can separate out pieces for portability.
/etc/nginx/conf.d/mythweb.include
I'd recommend creating a file /etc/nginx/conf.d/mythweb.include with the following contents
location /mythweb/ {
auth_basic "MythWeb";
auth_basic_user_file mythweb.passwd;
index /mythweb/mythweb.php;
try_files $uri @handler;
}
location ~ /mythweb/.+\.php {
include fastcgi_params;
fastcgi_index mythweb.php;
fastcgi_split_path_info ^(.+\.php)(/?.+)$;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param db_server localhost;
fastcgi_param db_name mythconverg;
fastcgi_param db_login mythtv;
fastcgi_param db_password mythtv;
fastcgi_param hostname mymythbox;
fastcgi_pass 127.0.0.1:9000;
}
location @handler {
rewrite /mythweb/(.+\.(php|pl))/.* /mythweb/$1 last;
rewrite /mythweb/(pl(/.*)?)$ /mythweb/mythweb.pl/$1 last;
rewrite /mythweb/(.+)$ /mythweb/mythweb.php/$1 last;
rewrite /mythweb/(.*)$ /mythweb/mythweb.php last;
}
When using php-fpm you can also the php fpm instance to hold the configuration for the database and backend (the fastcgi_param's db_server, db_name, db_login, db_password). Entirely up to you.
/etc/nginx/mythweb.passwd
You will also need to create /etc/nginx/mythweb.passwd. This is a standard apache style htpasswd file and should contain the username/passwords for authenticating logons to your mythweb install.
Site Config - /etc/nginx/conf.d/default.conf
The default site config is as follows
server {
listen 80;
server_name localhost;
location / {
root /usr/share/nginx/html;
index index.html index.htm;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}
}
This should be edited to include mythweb.include and update the site root as follows
server {
listen 80;
server_name localhost;
root /var/www/html;
location / {
index index.html index.htm;
}
include /etc/nginx/conf.d/mythweb.include;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root /usr/share/nginx/html;
}
}
You should now have mythweb running under nginx on localhost. It is left as an exercise for the reader to configure nginx to listen on a public ip address so that mythweb is reachable from the outside world.
How it works
For those that are interested, here's how all that hangs together.
The First Stanza
First lets examine the first stanza.
location /mythweb/ {
auth_basic "MythWeb";
auth_basic_user_file mythweb.passwd;
index /mythweb/mythweb.php;
try_files $uri @handler;
}
auth_basic and auth_basic_user_file provide our authentication for mythweb.
index tells nginx which file to select when just the directory /mythweb is requested.
Then the nginx magic starts.
The try_files line makes nginx try to find a file that directly matches the url being requested For example the mythtv logo is found at /mythweb/skins/default/img/mythtv-logo.png. nginx will find this file and directly return the content. Anything which cannot be found gets passed to the @handler stanza which we will look at later.
The second stanza
location ~ /mythweb/.+\.php {
include fastcgi_params;
fastcgi_index mythweb.php;
fastcgi_split_path_info ^(.+\.php)(/?.+)$;
fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
fastcgi_param PATH_INFO $fastcgi_path_info;
fastcgi_param db_server localhost;
fastcgi_param db_name mythconverg;
fastcgi_param db_login mythtv;
fastcgi_param db_password mythtv;
fastcgi_param hostname mymythbox;
fastcgi_pass 127.0.0.1:9000;
}
This tells nginx that anything which matches the regexp "/mythweb/.+\.php" should be passed onto the php backend for interpretation.
The include file fastcgi_params is the one shipped with the nginx package and contains all the recommended fastcgi params.
fastcgi_split_path_info tells nginx how to split up the request url to correctly populate the variable $fastcgi_path_info. We need this to set PATH_INFO. If the PHP variable $_SERVER['PATH_INFO'] isn't correctly set, then the whole of mythweb fails to work. Both Apache and lighttpd set this variable out of the box. The nginx folk consider PATH_INFO depreciated and that the application should do it's magic based upon the request url instead. Until that time, we have to go and set the PATH_INFO variable correctly :)
The fastcgi_param SCRIPT_FILENAME is setting another variable that apache and lighttpd populate by default.
The @handler Stanza
location @handler {
rewrite /mythweb/(.+\.(php|pl))/.* /mythweb/$1 last;
rewrite /mythweb/(pl(/.*)?)$ /mythweb/mythweb.pl/$1 last;
rewrite /mythweb/(.+)$ /mythweb/mythweb.php/$1 last;
rewrite /mythweb/(.*)$ /mythweb/mythweb.php last;
}
This is where all the rewrites happen. This is a translation of the original apache rewrite ruleset into an nginx rewrite ruleset.
Rule 1: This is a terminating rule to make sure we don't spiral down into a rewrite blackhole. Without this we decend into a rewrite blackhole /mythweb/mythweb.php/mythweb.php/mythweb.php... etc Once we've done the rewrite to include mythweb.php or mythweb.pl we don't need to rewrite again.
Rule 2: This hands off any request starting with /mythweb/pl to the mythweb.pl handler.
Rule 3: This is the main workhorse rewrite. It rewrites the pretty urls you see in the browser to one that feeds the request into mythweb.php. For example requests to /mythweb/status become /mythweb/mythweb.php/status. This will then match the regexp from stanza two and be fed into the php backend.
Rule 4: This matches anything else not previously matched and send it straight to the main mythweb.php script. This is primarily used for the front page.
MythWeb 0.24, nginx 1.4.1, php 5.5.1, and Debian
If running Debian testing/jessie as of Aug 2013, a few changes to the above may be necessary.
In The First Stanza, it may be necessary to change
index /mythweb/mythweb.php;
to
index mythweb.php;
In "includes/init.php", the order of the "require_once" calls have to be re-ordered; this example is based on 0.24-fixes:
<?php /** * This file is part of MythWeb, a php-based interface for MythTV. * See http://www.mythtv.org/ for details. * * Initialization routines. This file basically loads all of the necessary * shared files for the entire program. * * @url $URL$ * @date $Date$ * @version $Revision$ * @author $Author$ * @license GPL * * @package MythWeb * /**/ // Load the generic utilities so we have access to stuff like DEBUG() require_once 'includes/utils.php'; require_once 'includes/errors.php'; // Define some common stuff require_once 'includes/defines.php'; // Attempt to load up firephp if installed on the server @include_once('FirePHPCore/fb.php'); // Detect mobile users require_once 'includes/mobile.php'; // Setup the skins and themes require_once 'includes/skin.php'; // Lazy load the classes... require_once 'includes/class_autoload.php'; // Clean up some stuff require_once 'includes/cleanup.php'; // Check out the php version info require_once 'includes/php_version_check.php'; // Load the error trapping and display routines require_once 'includes/errors.php'; require_once 'includes/errordisplay.php'; // Setup the database require_once 'includes/database.php'; // Make sure the database is up to date require_once 'includes/db_update.php'; // Load the session handler routines require_once 'includes/session.php'; // Load the translation routines so the modules can translate their descriptions require_once 'includes/translate.php'; // Protect the users! require_once 'includes/lockdown.php'; // Include a few useful functions require_once 'includes/css.php'; require_once 'includes/mouseovers.php'; // Setup the data_dir require_once 'includes/data_dir.php'; // Load the session defaults and other config info require_once 'includes/config.php'; // And do some quick setup... MythBackend::find()->setTimezone();
After all the above, check the web page "Settings --> TV --> My Session" to make sure the Date Formats aren't blank. If they are, and choosing Reset doesn't restore them, changing modules/mythweb/tmpl/default/set_session.php as below may help (because it calls setlocale to return the current setting):
</tr><tr class="x-sep">
<th><?php echo t('Language') ?>:</th>
<td><?php language_select() ?></td>
</tr><tr class="x-sep">
<th><?php echo 'Current Locale' ?>:</th>
<td><?php echo '"'.setlocale(LC_ALL, 0).'"' ?></td>
