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

Setting up email routing to gmail / google apps via ISPConfig 3

The following guide describes the steps to add DNS records that route emails from a domain managed in ISPConfig 3 to google apps / gmail. The guide assumes that you have already setup the dns zone for your domain in ispconfig.

Login to ISPConfig, click on the DNS module icon in the upper navigation bar, then open the settings of the DNS zone that you want to redirect to google and click on the "records" tab. You should see a record list similar to this:

Now Delete the existing MX record and the "mail" A-Record. Then add the following new records:

CNAME Record:

Hostname: mail
Target: ghs.google.com.

MX Records:

example.com. ASPMX.L.GOOGLE.COM. 10
example.com. ALT1.ASPMX.L.GOOGLE.COM. 20
example.com. ALT2.ASPMX.L.GOOGLE.COM. 30
example.com. ASPMX2.GOOGLEMAIL.COM. 40
example.com. ASPMX3.GOOGLEMAIL.COM. 50

IMPORTANT: All full domain names like "ghs.google.com." have to end with a dot, if the dot is missing, the name is treated as subdomain of the zone.

The resulting record list should look like this:

Change of mail header form field identifier from ISPConfig 2 to ISPConfig 3

If you have a local mail server installed and change your server controlpanel to ISPConfig 3, having used ISPConfig 2 in the past, you may have to change the value that defines the form field observed by all functions in need of the address that mails are supposed to be delivered to (catchalls, etc.) on your mail server preferences since the identifier has changed from X-Delivered-To to Delivered-To in ISPConfig 3; otherwise the system won't be able to find the necessary information in the mails' headers.

Restart the server afterwards and you should find it working again.

Thanks to Alexander Fox for this post!

Fix “HTTP request length 134926 (so far) exceeds MaxRequestLen” error on Debian Linux

When you get a 500 error in a webpage hosted on Debian Linux (6.0) with apache webserver and fastcgi, take a look into the apache error.log file. This can either be the global error.log or the error.log of the website where you got the error. If you find a error similar to this one:

[Fri Apr 10 15:18:05 2012] [warn] [client 192.168.0.55] mod_fcgid: HTTP request length 134926 (so far) exceeds MaxRequestLen (131072), referer: http://www.example.tld/administrator/index.php?option=com_installer

then the MaxRequestLen setting of mod_fccgid is too low. To fix that, edit the file /etc/apache2/mods-available/fcgid.conf

vi /etc/apache2/mods-available/fcgid.conf

and add or edit the line "MaxRequestLen 15728640" to set the Request Limit to 15MB. The resulting file should contain these settings:

 AddHandler fcgid-script .fcgi
 FcgidConnectTimeout 20
 MaxRequestLen 15728640

Save the changes and restart apache:

/etc/init.d/apache2 restart

Debugging of ISPConfig 3 server actions in case of a failure

The follwing article describes the steps that can be taken to debug the ISPConfig 3 server scripts.

Enable the debug Loglevel in ISPConfig

Login to the ISPConfig intterface and set the log level to Debug under System > System > Server Config (see also chapter 4.9.2.2 of the ISPConfig 3 manual) for the affected server. After one or two minutes, there should be more detailed messages in ISPConfig's system log (Monitor > System State (All Servers) > Show System-Log).

Disable the server.sh cronjob

Go to the command line of the server on which the error happens (on multiserver systems, it is often the slave and not the master) and run (as root):

crontab -e

Comment out the server.sh cron job:

#* * * * * /usr/local/ispconfig/server/server.sh > /dev/null >> /var/log/ispconfig/cron.log

Run the server script manually to get detailed debug output

Then run the command:

/usr/local/ispconfig/server/server.sh

This will display any errors directly on the command line which should help you to fix the error. When you have fixed the error, please don't forget to uncomment the server.sh cron job again.

nginx server error: 413 Request Entity Too Large

The nginx webserver has a max. body size limit of 1 MB for requests as default. This might be too low for file uploads in scripts and you will see the following error message when you try to upload a file:

 413 Request Entity Too Large

The configuration variable for this option is "client_max_body_size" and it can be set in the http, server and location sections of the nginx configuration file. To set the Limit globally to 25 MB, edit the nginx.conf file and add:

client_max_body_size 20M;

in the http section.

Example for Ubuntu Linux:

user www-data;
worker_processes 4;
pid /var/run/nginx.pid;

events {
        worker_connections 768;
        # multi_accept on;
}

http {
        geoip_country  /etc/nginx/geoip/GeoIP.dat; # the country IP database
        geoip_city     /etc/nginx/geoip/GeoLiteCity.dat; # the city IP database
        ##
        # Basic Settings
        ##

        sendfile on;
        tcp_nopush on;
        tcp_nodelay on;
        keepalive_timeout 65;
        types_hash_max_size 2048;
        client_max_body_size 20M;

        include /etc/nginx/mime.types;
        default_type application/octet-stream;

        ##
        # Logging Settings
        ##

        access_log /var/log/nginx/access.log;
        error_log /var/log/nginx/error.log;

        ##
        # Gzip Settings
        ##

        gzip on;
        gzip_disable "msie6";

        ##
        # Virtual Host Configs
        ##

        include /etc/nginx/conf.d/*.conf;
        include /etc/nginx/sites-enabled/*;
}

Enhanced e-mail SPAM protection in ISPConfig 3

The command below enables a stricter SPAM handling for postfix on ISPConfig 3 servers.

In Detail:

  • Reject sender hostnames with invalid syntax
  • Reject sender hostnames that are no fully qualified domains (e.g. reject "server1" but allow server1.domain.tld)
  • Reject sender domains that have no DNS records
  • Check sender IP addresses against realtime blacklists.

First make a backup of the postfix main.cf file in case that you want to reverse the changes later:

cp -pf /etc/postfix/main.cf /etc/postfix/main.cf.bak

Then execute this command to enable the additional spam protection functions (the command is one line!).

postconf -e 'smtpd_recipient_restrictions = permit_mynetworks, permit_sasl_authenticated, reject_invalid_hostname, reject_non_fqdn_hostname, reject_unknown_recipient_domain, reject_non_fqdn_recipient, reject_unauth_destination, reject_non_fqdn_sender, reject_unknown_sender_domain, reject_unknown_recipient_domain, reject_rbl_client cbl.abuseat.org,reject_rbl_client dul.dnsbl.sorbs.net,reject_rbl_client ix.dnsbl.manitu.net, check_recipient_access mysql:/etc/postfix/mysql-virtual_recipient.cf, reject_unauth_destination'

Then restart postfix:

/etc/init.d/postfix restart

How to change the welcome email message text in ISPConfig 3

As of ISPConfig 3.0.4, the text of the welcome email message that is sent to new email accounts is stored in the folder /usr/local/ispconfig/server/conf/mail/.

The message has this format:

------------------------------------------------------------------------
From: ISPConfig <[email protected]>
Subject: Welcome to your new email account.

Welcome to your new email account. Your webmaster.
------------------------------------------------------------------------

The first line starts with "From: " followed by the sender email address. The second line starts with "Subject: " followed by the email subject. The third line should be empty. All following lines are the email text.

The email text files are named "welcome_email_<language>.txt" where <language> has to be replaced with the system language like "en" for English or "de" for German language, e.g. "welcome_email_en.txt" for the english welcome email.

The customized language file should be stored in the folder /usr/local/ispconfig/server/conf-custom/mail/ so that it does not get overwritten by ISPConfig updates.