The Perfect Server - CentOS 7 x86_64 (nginx, Dovecot, ISPConfig 3)

Version 1.0
Authors: Till Brehm, Srijan Kishore and Falko Timme
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This tutorial shows how to prepare a CentOS 7 x86_64 server for the installation of ISPConfig 3, and how to install ISPConfig 3 on it. ISPConfig 3 is a webhosting control panel that allows you to configure the following services through a web browser: nginx web server, Postfix mail server, MySQL, BIND nameserver, PureFTPd, SpamAssassin, ClamAV, Mailman, and many more. Since version 3.0.4, ISPConfig comes with full support for the nginx web server in addition to Apache; this tutorial covers the setup of a server that uses nginx, not Apache. The ISPConfig 3 apache perfect server tutorial is available here.

1. Requirements

To install such a system you will need the following

• Download the two CentOS 7.0 DVDs from a mirror next to you (the list of mirrors can be found here: http://isoredirect.centos.org/centos/7/isos/x86_64/CentOS-7.0-1406-x86_64-DVD.iso.
• A fast internet connection

2. Preliminary Note

In this tutorial I use the hostname server1.example.com with the IP address 192.168.0.100 and the gateway 192.168.0.1. These settings might differ for you, so you have to replace them where appropriate. Please install the minimal CentOS 7 installation from this tutorial link before proceeding ahead.

3 Install nano editor and adjust /etc/hosts

yum -y install nano wget

Next we edit /etc/hosts. Make it look like this:

nano /etc/hosts

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
192.168.0.100   server1.example.com     server1

::1         localhost localhost.localdomain localhost6 localhost6.localdomain6

and set the hostname to server1.example.com:

echo 'server1.example.com' > /etc/hostname

4 Configure The Firewall and install some basic network software

(You can skip this chapter if you have already disabled the firewall at the end of the basic system installation.)

I want to install ISPConfig at the end of this tutorial which comes with its own firewall. That's why I disable the default CentOS firewall now. Of course, you are free to leave it on and configure it to your needs (but then you shouldn't use any other firewall later on as it will most probably interfere with the CentOS firewall).

Run

systemctl stop firewalld.service
systemctl disable firewalld.service

and disable the firewall.

To check that the firewall has really been disabled, you can run

firewall-cmd --state

afterwards. The output should look like this:

[[email protected] ~]# firewall-cmd --state
not running
[[email protected] ~]#

yum -y install net-tools NetworkManager-tui

5 Disable SELinux

SELinux is a security extension of CentOS that should provide extended security. In my opinion you don't need it to configure a secure system, and it usually causes more problems than advantages (think of it after you have done a week of trouble-shooting because some service wasn't working as expected, and then you find out that everything was ok, only SELinux was causing the problem). Therefore I disable it (this is a must if you want to install ISPConfig later on).

Edit /etc/selinux/config and set SELINUX=disabled:

nano /etc/selinux/config

# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
#     enforcing - SELinux security policy is enforced.
#     permissive - SELinux prints warnings instead of enforcing.
#     disabled - No SELinux policy is loaded.
SELINUX=disabled
# SELINUXTYPE= can take one of these two values:
#     targeted - Targeted processes are protected,
#     mls - Multi Level Security protection.
SELINUXTYPE=targeted

Afterwards we must reboot the system:

reboot

6 Enable Additional Repositories And Install Some Software

We will enable EPEL repositories on our CentOS system as lots of the packages that we are going to install in the course of this tutorial are not available in the official CentOS 7.0 repositories:

yum -y install epel-release

yum -y install yum-priorities

Edit /etc/yum.repos.d/epel.repo...

nano /etc/yum.repos.d/epel.repo

... and add the line priority=10 to the [epel] section:

[epel]
name=Extra Packages for Enterprise Linux 7 - $basearch
#baseurl=http://download.fedoraproject.org/pub/epel/7/$basearch
mirrorlist=https://mirrors.fedoraproject.org/metalink?repo=epel-7&arch=$basearch
failovermethod=priority
enabled=1
priority=10
gpgcheck=1
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7

[...]

Then we update our existing packages on the system:

yum update

Now we install some software packages that are needed later on:

yum -y groupinstall 'Development Tools'

7 Quota

(If you have chosen a different partitioning scheme than I did, you must adjust this chapter so that quota applies to the partitions where you need it.)

To install quota, we run this command:

yum -y install quota

Now we check if quota is already enabled for the filesystem where the website (/var/www) and maildir data (var/vmail) is stored. In this example setup, I have one big root partition, so I search for ' / ':

mount | grep ' / '

[[email protected] ~]# mount | grep ' / '
/dev/mapper/centos-root on / type xfs (rw,relatime,attr2,inode64,noquota)
[[email protected] ~]#

If you have a separate /var partition, then use:

mount | grep ' /var '

instead. If the line contains the word "noquota", then proceed with the following steps to enable quota.

Enabling quota on the / (root) partition

Normally you would enable quota in the /etc/fstab file, but if the filesystem is the root filesystem "/", then quota has to be enabled by a boot parameter of the Linux Kernel.

Edit the grub configuration file:

nano /etc/default/grub

search fole the line that starts with GRUB_CMDLINE_LINUX and add rootflags=uquota,gquota to the commandline parameters so that the resulting line looks like this:

[...]

GRUB_CMDLINE_LINUX="rd.lvm.lv=centos/swap vconsole.font=latarcyrheb-sun16 rd.lvm.lv=centos/root crashkernel=auto  vconsole.keymap=us rhgb quiet rootflags=uquota,gquota"
[...]

and apply the changes by running the following command.

cp /boot/grub2/grub.cfg /boot/grub2/grub.cfg_bak
grub2-mkconfig -o /boot/grub2/grub.cfg

and reboot the server.

reboot

Now check if quota is enabled:

mount | grep ' / '

[[email protected] ~]# mount | grep ' / '
/dev/mapper/centos-root on / type xfs (rw,relatime,attr2,inode64,usrquota,grpquota)
[[email protected] ~]#

When quota is active, we can see "usrquota,grpquota" in the mount option list.

Enabling quota on a separate /var partition

If you have a separate /var partition, then edit /etc/fstab and add ,uquota,gquota to the / partition (/dev/mapper/centos-var):

nano /etc/fstab

#
# /etc/fstab
# Created by anaconda on Sun Sep 21 16:33:45 2014
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/centos-root /                       xfs     defaults        1 1
/dev/mapper/centos-var /var                     xfs     defaults,uquota,gquota        1 2
UUID=9ac06939-7e43-4efd-957a-486775edd7b4 /boot                   xfs     defaults        1 3
/dev/mapper/centos-swap swap                    swap    defaults        0 0

Then run

mount -o remount /var

quotacheck -avugm
quotaon -avug

to enable quota.

8 Synchronize The System Clock

It is a good idea to synchronize the system clock with an NTP (network time protocol) server over the Internet. Simply run

yum -y install ntp

and your system time will always be in sync.

9 Install MariaDB

We will install MariaDB-server and client as follows:

yum -y install mariadb mariadb-server

We want the Mariadb service to run on and after boot, and start the service as:

systemctl enable mariadb.service
systemctl start mariadb.service

Set passwords for the MySQL root account:

mysql_secure_installation

[[email protected] ~]# mysql_secure_installation
/usr/bin/mysql_secure_installation: line 379: find_mysql_client: command not found

NOTE: RUNNING ALL PARTS OF THIS SCRIPT IS RECOMMENDED FOR ALL MariaDB
      SERVERS IN PRODUCTION USE!  PLEASE READ EACH STEP CAREFULLY!

In order to log into MariaDB to secure it, we'll need the current
password for the root user.  If you've just installed MariaDB, and
you haven't set the root password yet, the password will be blank,
so you should just press enter here.<--ENTER

Enter current password for root (enter for none): <--ENTER
OK, successfully used password, moving on...

Setting the root password ensures that nobody can log into the MariaDB
root user without the proper authorisation.

Set root password? [Y/n]<--ENTER 
New password: <--yourmariadbpassword
Re-enter new password: <--yourmariadbpassword
Password updated successfully!
Reloading privilege tables..
 ... Success!


By default, a MariaDB installation has an anonymous user, allowing anyone
to log into MariaDB without having to have a user account created for
them.  This is intended only for testing, and to make the installation
go a bit smoother.  You should remove them before moving into a
production environment.

Remove anonymous users? [Y/n] <--ENTER
 ... Success!

Normally, root should only be allowed to connect from 'localhost'.  This
ensures that someone cannot guess at the root password from the network.

Disallow root login remotely? [Y/n]<--ENTER
 ... Success!

By default, MariaDB comes with a database named 'test' that anyone can
access.  This is also intended only for testing, and should be removed
before moving into a production environment.

Remove test database and access to it? [Y/n]<--ENTER
 - Dropping test database...
 ... Success!
 - Removing privileges on test database...
 ... Success!

Reloading the privilege tables will ensure that all changes made so far
will take effect immediately.

Reload privilege tables now? [Y/n] <--ENTER
 ... Success!

Cleaning up...

All done!  If you've completed all of the above steps, your MariaDB
installation should now be secure.

Thanks for using MariaDB!
[[email protected] ~]#

10 Install Dovecot

Dovecot can be installed as follows:

yum -y install dovecot dovecot-pigeonhole dovecot-mysql

Create a empty dovecot-sql.conf file and symlink:

touch /etc/dovecot/dovecot-sql.conf
ln -s /etc/dovecot/dovecot-sql.conf /etc/dovecot-sql.conf

Now create the system startup links and start Dovecot:

systemctl enable dovecot.service
systemctl start dovecot.service

11 Install Postfix

Postfix can be installed as follows:

yum -y install postfix

Then turn off Sendmail and start Postfix:

systemctl enable mariadb.service
systemctl start mariadb.service
systemctl stop sendmail.service
systemctl disable sendmail.service
systemctl enable postfix.service
systemctl restart postfix.service

12 Install Getmail

Getmail can be installed as follows:

yum -y install getmail

13 Install Amavisd-new, SpamAssassin, And ClamAV

To install amavisd-new, spamassassin and clamav, run the following command:

yum -y install amavisd-new spamassassin clamav clamd clamav-update unzip bzip2 unrar perl-DBD-mysql

Edit the freshclam configuration file /etc/freshclam.conf

nano /etc/freshclam.conf

and comment out the line "Example"

[....]
# Example
[....]

Then we start freshclam, amavisd, and clamd.amavisd:

sa-update
freshclam
systemctl enable amavisd.service

14 Install Nginx, PHP5 (PHP-FPM), And Fcgiwrap

Nginx is available as a package for CentOS 7.0 (from EPEL) which we can install as follows:

yum -y install nginx

If Apache2 is already installed on the system, stop it now...

systemctl stop httpd.service

... and remove Apache's system startup links:

systemctl disable httpd.service

Then we create the system startup links for nginx and start it:

systemctl enable nginx.service
systemctl start nginx.service

(If both Apache2 and nginx are installed, the ISPConfig 3 installer will ask you which one you want to use - answer nginx in this case. If only one of these both is installed, ISPConfig will do the necessary configuration automatically.)

We can make PHP5 work in nginx through PHP-FPM (PHP-FPM (FastCGI Process Manager) is an alternative PHP FastCGI implementation with some additional features useful for sites of any size, especially busier sites). We can install php-fpm together with php-cli and some PHP5 modules like php-mysql which you need if you want to use MySQL from your PHP scripts as follows:

yum -y install php-fpm php-cli php-mysql php-gd php-imap php-ldap php-odbc php-pear php-xml php-xmlrpc php-pecl-apc php-magickwand php-mbstring php-mcrypt php-mssql php-snmp php-soap php-tidy

Next we open /etc/php.ini...

nano /etc/php.ini

... and change the error reporting (so that notices aren't shown any longer):

[...]
;error_reporting = E_ALL & ~E_DEPRECATED & ~E_STRICT
error_reporting = E_ALL & ~E_NOTICE
[...]

Also set cgi.fix_pathinfo=0:

nano /etc/php.ini

[...]
; cgi.fix_pathinfo provides *real* PATH_INFO/PATH_TRANSLATED support for CGI.  PHP's
; previous behaviour was to set PATH_TRANSLATED to SCRIPT_FILENAME, and to not grok
; what PATH_INFO is.  For more information on PATH_INFO, see the cgi specs.  Setting
; this to 1 will cause PHP CGI to fix its paths to conform to the spec.  A setting
; of zero causes PHP to behave as before.  Default is 1.  You should fix your scripts
; to use SCRIPT_FILENAME rather than PATH_TRANSLATED.
; http://www.php.net/manual/en/ini.core.php#ini.cgi.fix-pathinfo
cgi.fix_pathinfo=0
[...]

(Please read http://wiki.nginx.org/Pitfalls to find out why you should do this.)

In addition to that, in order to avoid errors like

[08-Aug-2011 18:07:08] PHP Warning: phpinfo(): It is not safe to rely on the system's timezone settings. You are *required* to use the date.timezone setting or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Europe/Berlin' for 'CEST/2.0/DST' instead in /usr/share/nginx/html/info.php on line 2

... in /var/log/php-fpm/www-error.log when you call a PHP script in your browser, you should set date.timezone in /etc/php.ini:

[...]
[Date]
; Defines the default timezone used by the date functions
; http://www.php.net/manual/en/datetime.configuration.php#ini.date.timezone
date.timezone = "Europe/Berlin"
[...]

Next create the system startup links for php-fpm and start it:

systemctl enable php-fpm
systemctl restart php-fpm

PHP-FPM is a daemon process (with the init script /etc/init.d/php-fpm) that runs a FastCGI server on port 9000.

To get CGI support in nginx, we install Fcgiwrap.

Fcgiwrap is a CGI wrapper that should work also for complex CGI scripts and can be used for shared hosting environments because it allows each vhost to use its own cgi-bin directory.

As there's no fcgiwrap package for CentOS 7.0, we must build it ourselves. First we install some prerequisites:

yum -y install fcgi-devel

Now we can build fcgiwrap as follows:

cd /usr/local/src/
git clone git://github.com/gnosek/fcgiwrap.git
cd fcgiwrap
autoreconf -i
./configure
make
make install

This installs fcgiwrap to /usr/local/sbin/fcgiwrap.

Next we install the spawn-fcgi package which allows us to run fcgiwrap as a daemon:

yum -y install spawn-fcgi

Open /etc/sysconfig/spawn-fcgi...

nano /etc/sysconfig/spawn-fcgi

... and modify the file as follows:

# You must set some working options before the "spawn-fcgi" service will work.
# If SOCKET points to a file, then this file is cleaned up by the init script.
#
# See spawn-fcgi(1) for all possible options.
#
# Example :
#SOCKET=/var/run/php-fcgi.sock
#OPTIONS="-u apache -g apache -s $SOCKET -S -M 0600 -C 32 -F 1 -P /var/run/spawn-fcgi.pid -- /usr/bin/php-cgi"

FCGI_SOCKET=/var/run/fcgiwrap.socket
FCGI_PROGRAM=/usr/local/sbin/fcgiwrap
FCGI_USER=apache
FCGI_GROUP=apache
FCGI_EXTRA_OPTIONS="-M 0770"
OPTIONS="-u $FCGI_USER -g $FCGI_GROUP -s $FCGI_SOCKET -S $FCGI_EXTRA_OPTIONS -F 1 -P /var/run/spawn-fcgi.pid -- $FCGI_PROGRAM"

Now add the user nginx to the group apache:

usermod -a -G apache nginx

Create the system startup links for spawn-fcgi...

chkconfig spawn-fcgi on

... and start it as follows:

systemctl start spawn-fcgi

You should now find the fcgiwrap socket in /var/run/fcgiwrap.socket, owned by the user and group apache (some scripts, e.g. Mailman, expect to be run by the user/group apache, that's why we don't run spawn-fcgi as user/group nginx, but instead add nginx to the apache group).

14.1 Additional PHP Versions

Starting with the ISPConfig 3.0.5, it is possible to have multiple PHP versions on one server (selectable through ISPConfig) which can be run through FastCGI and PHP-FPM. The procedure of building additional PHP versions on CentOS is described in this tutorial: How To Use Multiple PHP Versions (PHP-FPM & FastCGI) With ISPConfig 3 (CentOS 6.3)