How to renew the ISPConfig 3 SSL Certificate

This tutorial describes the steps to renew the SSL Certificate of the ISPConfig 3 control panel. There are two alternative ways to achieve that:

  1. Create a new OpenSSL Certificate and CSR on the command line with OpenSSL.
  2. Renew the SSL Certificate with the ISPConfig updater

I'll start with the manual way to renew the ssl cert.

1) Create a new ISPConfig 3 SSL Certificate with OpenSSL

Login to your server on the shell as root user. Before we create a new SSL Cert, backup the current ones. SSL Certs are security sensitive so I'll store the backup in the /root/ folder.

tar pcfz /root/ispconfig_ssl_backup.tar.gz /usr/local/ispconfig/interface/ssl
chmod 600 /root/ispconfig_ssl_backup.tar.gz

Now create a new SSL Certificate key, Certificate Request (csr) and a self signed Certificate.

cd /usr/local/ispconfig/interface/ssl
openssl genrsa -des3 -out ispserver.key 4096
openssl req -new -key ispserver.key -out ispserver.csr
openssl x509 -req -days 3650 -in ispserver.csr \
-signkey ispserver.key -out ispserver.crt
openssl rsa -in ispserver.key -out ispserver.key.insecure
mv ispserver.key ispserver.key.secure
mv ispserver.key.insecure ispserver.key

Restart Apache to load the new SSL Certificate.

service apache2 restart

2) Renew the SSL Certificate with the ISPConfig installer

The alternative way to get a new SSL Certificate is to use the ISPConfig update script.
Download ISPConfig to the /tmp folder, unpack the archive and start the update script.

cd /tmp
wget http://www.ispconfig.org/downloads/ISPConfig-3-stable.tar.gz
tar xvfz ISPConfig-3-stable.tar.gz
cd ispconfig3_install/install
php -q update.php

The update script will ask the following question during update:

Create new ISPConfig SSL certificate (yes,no) [no]:

Answer "yes" here and the SSL Certificate creation dialog will start.

Enable image caching in apache for better Google Page Speed results

High page speed and short page load times of your website are essential for good search engine rankings today. In this FAQ, I will show you how to enable caching of graphic and CSS files in apache on Ubuntu and Debian.

The first step is to enable the expires module in apache:

a2enmod headers expires

This module allows the apache web server to set HTTP headers, in this case, to set the modification header for static assets like image and CSS files that don't change often.

Add the following config snippet inside the vhost file of the web site or at the end of the file /etc/apache2/apache2.conf to enable it globally.

<FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)$">
Header set Cache-Control "max-age=3024000, public"
</FilesMatch>

Finally reload apache to apply the configuration change.

service apache2 reload

On ISPConfig 3 servers, the snippet can be added in the "Apache Directives" field of the website instead. There is no apache reload required as ISPConfig takes care about that.

How to add PHP support for jailed SSH users in ISPConfig 3

Jailkit is an easy to use tool to create and maintain jail environments for shell users on Linux. In this guide, I will show you how to move PHP and its dependencies into the jail so that the jailed user can execute PHP scripts inside the jail.
Continue reading How to add PHP support for jailed SSH users in ISPConfig 3

Which ports are used on a ISPConfig 3 server and shall be open in the firewall?

Here is a list of ports that are used commonly on ISPConfig 3 servers. If you don't have all services installed or if you e.g. don't want to connect to MySQL from external servers, then close the unused or unwanted ports.

TCP ports

20 - FTP Data
21 - FTP Command
22 - SSH
25 - Email
53 - DNS
80 - HTTP (Webserver)
110 - POP3 (Email)
143 -Imap (Email)
443 - HTTPS (Secure web server)
993 - IMAPS (Secure Imap)
995 - POP3S (Secure POP3)
3306 - MySQL Database server
8080 - ISPConfig web interface
8081- ISPConfig apps vhost

UDP ports

53 - DNS
3306 - MySQL

Solution for: fatal: open database /var/lib/postfix/smtpd_scache.db: File exists

If your mail server stops working (neither incoming nor outgoing email works) and you find the following error message in the mail.log file:

fatal: open database /var/lib/postfix/smtpd_scache.db: File exists

then the smtpd_scache.db might got corrupted. Postfix will recreate this file if it does not exist. So it can be removed to solve the issue:

/etc/init.d/postfix stop
rm -f /var/lib/postfix/smtpd_scache.db
/etc/init.d/postfix start

Thanks to Alexander Fox for sending me this FAQ.

Solution for dovecot error: /path/ is no longer mounted. If this is intentional, remove it with doveadm mount

Dovecot is watching the whole server filesystem for modifications and removed or added sub filesystems. If you get errors similar to this one on your server:

Aug 30 09:10:23 server1 dovecot: master: Warning: /var/www/clients/client1/web1/log is no longer mounted. If this is intentional, remove it with doveadm mount

 (the directory path may vary), then you can fix it by excluding the path from being watched by dovecot. In my case, dovecot shall not watch my website directories as they do not contain any mailboxes

Run the following command on the shell as root user:

doveadm mount add '/var/www/*' ignore

To exclude all files and folders in /var/www from deovecot monitoring.

 

Solution for amavisd error – TROUBLE in process_request: Error writing a SMTP response to the socket: Broken pipe – on OpenVZ server

If you get error messages from amavisd similar to the one posted below on a server which is virtualized with OpenVZ:

Mar  5 09:09:02 v100 amavis[17378]: (17378-14) (!!)TROUBLE in process_request: Error writing a SMTP response to the socket: Broken pipe at (eval 100) line 987, <GEN44> line 31.

then the issue can be caused by the NUMTCPSOCK value in the openvz limits. Even if the barrier of this limit was never met in /proc/user_beancounters, the above error occurs when more then 25% of all TCP sockets were used. The solution is to set the NUMTCPSOCK barrier and limit to a high value in the openvz container configuration file. Here a value that worked for me on a moderately used mailserver:

NUMTCPSOCK="2000:2000"

Finally restart the OpenVZ VM to apply the new limit value.

 

Apache mod_security settings for WordPress and ModX

If you use the apache mod_security module on your apache server, you might encounter wrong 403 errors for several URL's of the cms systems. Here are some exception rules to avoid that:

For WordPress Blogs

<locationmatch "/wp-admin/admin-ajax.php">
SecRuleRemoveById 300013
SecRuleRemoveById 300015
SecRuleRemoveById 300016
SecRuleRemoveById 300017
</locationmatch>

<locationmatch "/wp-admin/page.php">
SecRuleRemoveById 300013
SecRuleRemoveById 300015
SecRuleRemoveById 300016
SecRuleRemoveById 300017
</locationmatch>

<locationmatch "/wp-admin/post.php">
SecRuleRemoveById 300013
SecRuleRemoveById 300015
SecRuleRemoveById 300016
SecRuleRemoveById 300017
</locationmatch>

For the ModX CMS

<LocationMatch "/manager/index.php">
SecRuleRemoveById 300016
</LocationMatch>

<LocationMatch "/connectors/resource/index.php">
SecRuleRemoveById 300013 300014 300015 300016
</LocationMatch>

<LocationMatch "/connectors/element/tv.php">
SecRuleRemoveById 300013 300016
</LocationMatch>

Add these rules inside the vhost file of the website. If you use ISPConfig to manage the server, then add the rules in the apache directives field of the website settings in ispconfig.

Many thanks to PlanetFox for providing the rules.

How to disable MySQL replication on master/master andmaster/slave setups

The following guide shows how to disable and remove mysql replication from two or more mysql servers. These steps can be used for master/slave and master/master mysql setups. The following SQL commands have to be be executed in phpmyadmin or with the mysql commandline program. It is just important that you are logged in as mysql root user. Below I will use the mysql commandline client.

Login into mysql as root user from commandline:

mysql -u root -p

the mysql command will ask for the mysql root password.

Then execute these commands if the installed mysql version is < 5.5.16:

STOP SLAVE;
RESET SLAVE;
QUIT

use the commands below instead if the mysql version is > 5.5.16

STOP SLAVE;
RESET SLAVE ALL;
QUIT

Now edit the my.cnf file (/etc/mysql/my.cnf) and add a # in front of all lines that start with "replicate-" or "master-". Example:

# replicate-same-server-id = 0
# master-host = 192.168.0.105
# master-user = slaveuser
# master-password = akst6Wqcz2B
# master-connect-retry = 60

Then restart mysql:

/etc/init.d/mysql restart