The cPanel Admin » php

Overview of PHP Handlers

Vanessa — Wed, 04 Aug 2010 19:30:02 +0000

One user on the cPanel forums spent some time summarizing the four PHP handlers,currently available via EasyApache, into a neat little chart that makes it easy to do a quick comparison. With that user’s permission, I’m posting the chart here:

Click on the image for the original-sized diagram. Thanks to Miraenda from errorcodex.com for providing it!

Automating Apache and PHP Updates

Vanessa — Wed, 19 May 2010 14:58:58 +0000

A lot of hosts that deploy a large number of servers are automating updates instead of running them manually. While cPanel updates can be automated as well, it’s become a common question of how to automate Apache and PHP updates across a large number of servers without having to manually run EasyApache on each server, which can be a very time-consuming process. If Apache and PHP were built via RPM, you could simply run a yum update. However, since they are built with EasyApache it’s not quite as simple as updating an RPM, but it’s still very easy to automate.

A few things I want to mention before you consider automating Apache and PHP updates:

You shouldn’t do this unless you have cPanel updates running automatically as well, for stable and release builds only. This reduces the chance of something going wrong and leaving you with broken builds across a ton of servers
Always test your build first on one server before deploying

Scenario:

You have a large number of servers that are set up almost identically, and you want to schedule monthly updates to make sure PHP and Apache are always up to date, but still similar to provide consistency.

The easiest way to set this up is as follows:

1) Run EasyApache on one of the servers, configure your build as you wish, then save the profile. I would also recommend running the build to make sure that it works properly before you deploy it.

2) Go into /var/cpanel/easy/apache/profile and look for a file called _last_success.yaml. This will be the one you just saved, unless you updated a template that was already named, or you know for a fact that it’s named something else. Rename this template to something you would recognize, like latest.yaml. Edit the yaml file and change these fields:

name: Shared server build
note: “Default build for all shared servers”

The name and note will identify the build in your EasyApache interface.

3) Move this script to the ‘custom’ folder (/var/cpanel/easy/apache/profile/custom)

From here, what I recommend doing is uploading the build template to a repository so it can be easily “grabbed”. That way each time you update the build, you would update the template in the repository and automate the command that downloads it and builds Apache. Since I named my yaml file latest.yaml, this is the command I’d run via cron on all my servers:

wget -O /var/cpanel/easy/apache/custom/latest.yaml http://repo.mydomain.com/ea/latest.yaml && /scripts/easyapache –profile=latest.yaml –build

The following command builds the profile automtically:

/scripts/easyapache –profile=latest.yaml –build

The latest.yaml file is the file name of the template I’m using, and –build indicates that the build should be started immediately instead of loading the EA configuration screen.

Here are a couple other options you might want to pass to /scripts/easyapache:

–do_not_revert_on_conf_failure : Use if you want to fix httpd.conf problems manually after the build. NOT recommended for automated EA updates
–skip-cpanel-version-check: Use if you don’t run automated cPanel updates and don’t want EasyApache to prompt for an update
–always_do_the_latest_phps : Always use the latest PHP version, keeping in mind that “latest version” refers to the latest version available in EA
–always_do_the_oldest_phps : Always use the oldest PHP version available in EA

You may also want to consider using hooks to automate post-build tests, and report any issues that may arise. Hooks are events/commands that run before or after a specific action. You can read more about hooks below:

http://etwiki.cpanel.net/twiki/bin/view/EasyApache3/EasyApacheHooks

PHP 500 Internal Server Errors

Vanessa — Mon, 17 May 2010 18:54:23 +0000

500 Internal Server Errors are one of the most common PHP issues that I see customer experience, and it will occur mostly on servers with suPHP or PHP running as CGI. These errors can be caused by something on the server, or an issue on the user’s site. Here ‘s what you should do if you see errors:

Check the logs

You can solve most problems quickly just by looking at the logs:

/usr/local/apache/logs/error_log

/usr/local/apache/logs/suphp.log

Here are some common errors:

SoftException in Application.cpp:357: UID of script "/home/user/public_html/test.php" is smaller than min_uid

SoftException in Application.cpp:422: Mismatch between target UID (511) and UID (510) of file "/home/user/public_html/test.php"

SoftException in Application.cpp:264: File "/home/user/public_html/test.php" is writeable by others

These are all permission/ownership issues, indicating that the owner of the PHP file being called in incorrect, or the permissions are higher than what is allowed in suphp.conf.

Invalid directions in .htaccess

If you’re running PHP in CGI or suPHP mode, you can’t use php_flag or php_value directives in .htaccess – you either need to use htscanner to allow Apache to parse those commands, or make php-related changes in php.ini within the user’s account. You can check the Apache error log in /usr/local/apache/logs/error_log to see if you get something like this:

/home/user/public_html/.htaccess: Invalid command 'php_flag', perhaps misspelled or defined by a module not included in the server configuration

If the error log indicates a problem with .htaccess, you need to remove the directives indicated and make sure your ssyntax is correct, and that they are in the correct places.

Incorrect ownership or permissions

PHP scripts and their immediate parent folder will usually have permissions limits when PHP runs in CGI/suPHP mode. By default, PHP files and their parent folders can not have group or ‘other’ writable permissions, and cannot be owned by a user on the system other than than the user that owns the home folder it is located in. Additionally, cPanel’s implementation of suPHP does not allow PHP to execute via browser from locations that are not inside a user’s home folder. The first thing you should check is that the PHP script and its parent folder(s) are not writable by ‘group’ or ‘other’, or owned by a different system user. You can usually see if this is an issue by tailing the suphp log in /usr/local/apache/logs/suphp.log, or whatever the suphp.conf has set as the log location.

You can adjust suPHP’s permissions allowances in /opt/suphp/etc/suphp.conf to allow ‘group’ and ‘other’ writable permissions if it’s necessary by modifying these values:

allow_file_group_writeable=false allow_file_others_writeable=false allow_directory_group_writeable=false allow_directory_others_writeable=false

If the problem is with the min_uid value being too low (such as if you’re running a PHP script as root), you can also modify the “min_uid” and “min_gid” values to be more permissive. Changing anything in the suphp.conf requires a restart of Apache.

SuPHP binary missing its “sticky” permissions

Take a look at the suphp binary. It should look a bit like this, and in most shells, will be highlighted in red:

-rwsr-xr-x 1 root root 341K Mar 30 12:25 /opt/suphp/sbin/suphp*

If it’s missing the ‘s’ in the permissions column, you need to re-add the sticky bit to allow users on the system to execute it properly:

chmod +s /opt/suphp/sbin/suphp

Last resort

If all else fails, you could be running a bum Apache build. Try running EasyApache to reinstall to see if that fixes the problem. You can also submit a support request to us and we may be able to fix this for you:

Dynamic PHP Extensions Not Loading

Vanessa — Tue, 04 May 2010 21:37:20 +0000

I recently saw an issue on one of our servers where we were trying to enable Zend Optimizer and IonCube Loaders, but they just won’t show up on a phpinfo page despite showing up via command line:

-bash-3.2# php -v PHP 4.4.9 (cli) (built: May 4 2010 13:55:07) Copyright (c) 1997-2008 The PHP Group Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies with the ionCube PHP Loader v3.3.14, Copyright (c) 2002-2010, by ionCube Ltd., and with Zend Optimizer v3.3.3, Copyright (c) 1998-2007, by Zend Technologies
After toggling around with this and finally getting cPanel installed, one of their techs (Kyle P.) figured out that the problem is with PHP being built with the versioning extension, which can apparently cause dynamic modules not to load when PHP is invoked as a DSO (and likely as CGI, but couldn’t reproduce it). The CPanel documentation also recommends against it:

“Versioning – The PHP versioning option was intended to allow the same sort of functionality that the concurrent DSO patches allow. It does not work well and is not recommended by cPanel or the PHP developers.”

Quite honestly, I never used versioning on a server and I knew it wasn’t something that was recommended, but at least now we know why!

Executable not set-uid root

Vanessa — Mon, 03 May 2010 03:44:16 +0000

One of the servers here at work was giving a 500 Internal Server error whenever a PHP page was loaded. Among the various things that can cause this error when you’re running PHP in CGI mode (suPHP), this error showing up in the Apache log was most unusual. Turns out it’s due to the suphp binary missing its sticky/suid permissions.

SecurityException in Application.cpp:188: Do not have root privileges. Executable not set-uid root?

To fix, simply chmod +s the suphp binary:

chmod +s /opt/suphp/bin/suphp

Re-Installing Auxiliary cPanel Software

Vanessa — Thu, 01 Apr 2010 15:52:56 +0000

Cpanel has a lot of supporting software that you may be using on your server. In case something goes amiss, here is a list of scripts that reinstall cpanel-provided software on your system. For most all of these, you can pass a –force as an argument to force a reinstall of the application.

cPanel
/scripts/upcp

MySQL
/scripts/mysqlup

PostgreSQL
/scripts/installpostgres

Roundcube
/usr/local/cpanel/bin/update-roundcube

Horde
/usr/local/cpanel/bin/update-horde

Squirrelmail
/usr/local/cpanel/bin/update-squirrelmail

phpMyAdmin
/usr/local/cpanel/bin/updatephpmyadmin

pureFTP
/scripts/ftpup –force (See: Installing and Configuring pure-FTP)

Exim
/scripts/eximup

Courier IMAP
/scripts/courierup –force (See: Installing/Configuring Courier IMAP)

Dovecot
/scripts/dovecotup –force (See: Installing and Configuring Dovecot)

cpAddons
/scripts/cpaddonsup

NSD/BIND
/scripts/setupnameserver (NSD:/scripts/nsdup)

Apache/PHP
/scripts/easyapache (See: EasyApache)

suPHP
/scripts/suphpup

cPanel Internal PHP
/scripts/makecpphp

FrontPage Extensions
/scripts/fpupgrade

Mailman
/scripts/reinstallmailman (will not remove list data)

cpHulkd
/usr/local/cpanel/bin/hulkdsetup

Ruby
/scripts/installruby