LAMP is essentially a server that runs Linux, Apache, MySQL and Php/Perl and is more commonly known as a LAMP server. This guide provides step-by-step instructions for installing a full-featured LAMP server on a CentOS 6 .0

1. Update system

Before proceeding to install, update the system with the following command

# yum update

2. Install and Configure the Apache Web Server

The Apache web server is the most popular server online, used on more than 70% of all servers connected to the World Wide Web. And there are good reasons for it: it’s free, it’s very stable, it delivers a great performance, it’s very customizable. To install the current version of the Apache web server use the following command

# yum install httpd

If you want to run Apache by default when the system boots, type the following command

# chkconfig httpd --level 2345 on

To start Apache for the first time, type the following command

# /etc/init.d/httpd start

3. Apache Web Server Security and Optimization

1. Disable any unnecessary apache modules, type the following command

# vi /etc/httpd/conf/httpd.conf

My example configuration is here

LoadModule auth_basic_module modules/mod_auth_basic.so
LoadModule auth_digest_module modules/mod_auth_digest.so
LoadModule authn_default_module modules/mod_authn_default.so
LoadModule authz_host_module modules/mod_authz_host.so
LoadModule authz_user_module modules/mod_authz_user.so
LoadModule authz_default_module modules/mod_authz_default.so
LoadModule include_module modules/mod_include.so
LoadModule log_config_module modules/mod_log_config.so
LoadModule env_module modules/mod_env.so
LoadModule mime_magic_module modules/mod_mime_magic.so
LoadModule expires_module modules/mod_expires.so
LoadModule deflate_module modules/mod_deflate.so
LoadModule headers_module modules/mod_headers.so
LoadModule setenvif_module modules/mod_setenvif.so
LoadModule mime_module modules/mod_mime.so
LoadModule status_module modules/mod_status.so
LoadModule autoindex_module modules/mod_autoindex.so
LoadModule info_module modules/mod_info.so
LoadModule negotiation_module modules/mod_negotiation.so
LoadModule dir_module modules/mod_dir.so
LoadModule actions_module modules/mod_actions.so
LoadModule alias_module modules/mod_alias.so
LoadModule rewrite_module modules/mod_rewrite.so

2. Optimize Timeout & KeepAlive
You need to control Timeouts & KeepAlive to improve server performance. Type the following command

# vi /etc/httpd/conf/httpd.conf

Find & Edit it as follows

Timeout 10
KeepAlive On
MaxKeepAliveRequests 200
KeepAliveTimeout 5

3. Optimize MPM (Multi-Processing Module)
Apache’s default installation of MPM Prefork. To optimize MPM Prefork, type the following command

# vi /etc/httpd/conf/httpd.conf

Find

<IfModule prefork.c>

Edit it as follows

<IfModule prefork.c>
    StartServers          5
    MinSpareServers      10
    MaxSpareServers      15
    ServerLimit         450
    MaxClients          450
    MaxRequestsPerChild   0
</IfModule>

Which,

# StartServers: number of server processes to start
# MinSpareServers: minimum number of server processes which are kept spare
# MaxSpareServers: maximum number of server processes which are kept spare
# ServerLimit: maximum value for MaxClients for the lifetime of the server
# MaxClients: maximum number of server processes allowed to start
# MaxRequestsPerChild: maximum number of requests a server process serves

4. Enable Mod_rewite
To enable mod_rewirte, type the following command

# vi /etc/httpd/conf/httpd.conf

Find

<Directory "/var/www/html">

Edit it as follows

<Directory "/var/www/html">
    AllowOverride All
    Options -MultiViews -Indexes FollowSymlinks IncludesNoExec +Includes
<Limit GET POST OPTIONS PROPFIND>
    Order allow,deny
    Allow from all
</Limit>
<LimitExcept GET POST OPTIONS PROPFIND>
    Order deny,allow
    Deny from all
</LimitExcept>
</Directory>

5. Enable File Caching
Enabling file caching can greatly improve your site’s performance and speed. If you want to enable file caching, type the following command

# vi /etc/httpd/conf/httpd.conf

Find

<Directory "/var/www/html">

Edit it as follows

<Directory "/var/www/html">
    AllowOverride All
    Options -MultiViews -Indexes FollowSymlinks IncludesNoExec +Includes
<Limit GET POST OPTIONS PROPFIND>
    Order allow,deny
    Allow from all
</Limit>
<LimitExcept GET POST OPTIONS PROPFIND>
    Order deny,allow
    Deny from all
</LimitExcept>
<FilesMatch "\.(flv|swf|ico|gif|jpg|jpeg|png|html|css)$">  
	Header set Cache-Control "max-age=604800, public"  
</FilesMatch>
</Directory>

4. Install and Configure MySQL Database Server

MySQL Server is one of the most popular database servers in the world, especially for use with dynamic, content rich websites. To install MySQL database server use the following command

# yum install mysql mysql-server

After installing MySQL, I highly recommend to run mysql_secure_installation, a program that helps secure MySQL. Important points to note are:
1. Be sure that the root account has a secure password set.
2. Do not create an anonymous account, and if it exists, say “yes” to remove it.
3. If your web server and MySQL server are on the same machine, you should disable the network access.

If you want to run MySQL by default when the system boots, type the following command

# chkconfig mysqld--level 2345 on

To start MySQL for the first time, type the following command

# /etc/init.d/mysqld start

5. Installing and Configuring PHP

PHP is a general-purpose scripting language originally designed for web development to produce dynamic web pages. Many popular web applications like WordPress, Joomla, Drupal, OScommerce, Magento are written in PHP. To install PHP on CentOS use the following command

# yum install php53 php53-mysql

To create secure PHP configuration settings, type the following command

# vi /etc/php.ini

Find & Edit it as follows

allow_url_fopen = Off 
display_errors = Off 
display_startup_errors = Off 
log_errors = On 
error_reporting = E_ALL 
expose_php = Off 
magic_quotes_gpc = On 
magic_quotes_sybase = Off 
register_globals = Off
max_execution_time = 60
memory_limit = 64M

To prevent run PHP scripts with a different file extension, type the following command

# vi /etc/httpd/conf.d/php.conf

Find

AddHandler php5-script .php
AddType text/html .php

Replace it as follows

<FilesMatch \.php$>
	AddHandler php5-script .php
	AddType text/html .php
</FilesMatch>

Restart Apache to reload new configurations. Type the following command

# /etc/init.d/httpd restart

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Memcache extension provides handy procedural and object oriented interface to memcached, highly effective caching daemon, which was especially designed to decrease database load in dynamic web applications. This article will explain how to install the memcache PHP extension on Centos/RedHat/Fedora.

The first, download the latest & stable package from http://pecl.php.net/package/memcache. Type the following command

# wget http://pecl.php.net/get/memcache-2.2.6.tgz

Extract memcache-2.2.6.tgz

# tar zxvf memcache-2.2.6.tgz

To install memcache extension, you need to install the php-devel package that matches the version of php that you are currently running. Example, i’m using PHP 5.3 then enter

# yum install php53-devel

Run the phpize command to prepare the build environment for a PHP extension

# phpize

Sample output

Configuring for:
PHP Api Version:         20090626
Zend Module Api No:      20090626
Zend Extension Api No:   220090626

Configure & Install memcache extension. Type the following command

# ./configure
# make
# make install

If your get the following error message when run ./configure

checking for the location of ZLIB... no
checking for the location of zlib... configure: error: memcache support requires ZLIB. Use --with-zlib-dir= to specify prefix where ZLIB include and library are located

Then type the following command to fix it

# yum install zlib zlib-devel

Finally, use the following command to add memcache extension to php.ini

# echo "extension=memcache.so" >> /etc/php.ini

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Neither the zip nor the unzip utilities are included in the default install of Linux. To install them from shell prompt, you must be a root user and type following two commands to install zip and unzip program.

If you are using RedHat / CentOS / Fedora then enter

# yum install zip unzip

If you are using Ubuntu / Debian then enter

# apt-get install zip unzip

zip examples

Creates the archive data.zip and puts all the files in the current directory in it in compressed form, type the following command

$ zip data *

To zip up an entire directory, type the following command

$ zip -r data *

To put the zip archive in the directory /tmp and copying over data.zip to the current directory, enter

$ zip -b /tmp data *

unzip examples

To use unzip to extract all files of the archive pics.zip into the current directory, enter

$ unzip data.zip

To extract all files into the /tmp directory, enter

$ unzip data.zip -d /tmp

To list all files from data.zip, enter

$ unzip -l data.zip

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If you are running RedHat / CentOS 32 bit and have 4 GB or more RAM use the Linux kernel compiled for PAE capable machines. Your machine may not show up total 4GB ram with 32 bit architecture servers. All you have to do is install PAE kernel package.

What is PAE ?

Physical Address Extension (PAE) is a technology which allows 32 bit operating systems to use up to 64 Gb of memory (RAM), something which is normally achieved by switching to a 64 bit system.

The Linux kernel includes full PAE mode support starting with version 2.3.23, enabling access of up to 64 GB of memory on 32-bit machines. A PAE-enabled Linux-kernel requires that the CPU also support PAE.

How to install PAE kernel?

Type the following command as root

# yum install kernel-PAE -y

Just reboot the server and make sure you boot with PAE kernel

# shutdown -r now

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What is OpenSSH ?

OpenSSH is a FREE version of the SSH connectivity tools that technical users of the Internet rely on. Users of telnet, rlogin, and ftp may not realize that their password is transmitted across the Internet unencrypted, but it is. OpenSSH encrypts all traffic (including passwords) to effectively eliminate eavesdropping, connection hijacking, and other attacks. Additionally, OpenSSH provides secure tunneling capabilities and several authentication methods, and supports all SSH protocol versions.

Install OpenSSH under CentOS Linux

To install the server and client type the following command:

[root@lifelinux ~]# yum install openssh-server

Start the service:

[root@lifelinux ~]# service sshd start

Set sshd service to automatically start at boot time, type the following command

[root@lifelinux ~]# chkconfig sshd on

Check & Make sure port 22 is opened:

[root@lifelinux ~]# netstat -tulpn | grep :22

Sample outputs:

tcp        0      0 :::22                       :::*                        LISTEN      1703/sshd

OpenSSH Server Configuration

Now you need to edit the /etc/ssh/sshd_config file using vi or any other editor and you need to change the following Directives or add the following directives for OpenSSH server configuration these are only some of basic directives if you want to know available directives check here
To change SSH listening port, example change port to 2222

Port 2222

To disable root logins, edit or add as follows:

PermitRootLogin no

Allow only SSH protocol 2

Protocol 2

Allow only user1 and user2 over SSH:

AllowUsers user1 user2

Firewall Settings

Open /etc/sysconfig/iptables file, enter:

[root@lifelinux ~]# vi /etc/sysconfig/iptables

Add the following line

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 22 -j ACCEPT

Save and close the file. Restart the firewall:

[root@lifelinux ~]# /etc/init.d/iptables restart

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rpm is a powerful Package Manager, which can be used to build, install, query, verify, update, and erase individual software packages. A package consists of an archive of files and meta-data used to install and erase the archive files. The meta-data includes helper scripts, file attributes, and descriptive information about the package. Packages come in two varieties: binary packages, used to encapsulate software to be installed, and source packages, containing the source code and recipe necessary to produce binary packages.

Install RPM File

To install an rpm file, open a terminal and then type the following command:

[root@server2 ~]# rpm -ivh file.rpm

Note:
-i: Installs a new package
-v: Print verbose information – normally routine progress messages will be displayed.
-h: Print 50 hash marks as the package archive is unpacked. Use with -v|–verbose for a nicer display.

Upgrade RPM File

[root@server2 ~]# rpm -Uvh file.rpm

Note:
-U: Upgrades or installs the package currently installed to a newer version. This is the same as install, except all other version(s) of the package are removed after the new package is installed.

Erase RPM File

[root@server2 ~]# rpm -ev ile.rpm

Note:
-e: Erase command
The following options may also be used:

--nodeps

Don’t check dependencies before uninstalling the packages.

List of all install packages

Type the following command:

[root@server2 ~]# rpm -qa 

Sample outputs:

...
libxslt-devel-1.1.17-2.el5_2.2
perl-libwww-perl-5.805-1.1.1
libc-client-devel-2004g-2.2.1
libidn-devel-0.6.5-1.1
libjpeg-devel-6b-37
gmp-devel-4.1.4-10.el5
libmcrypt-devel-2.5.8-4.el5.centos
libtidy-0.99.0-12.20070228.el5.centos
libtool-ltdl-1.5.22-7.el5_4
gpg-pubkey-1aa78495-3eb24301
openssl-0.9.8e-12.el5_5.7
NetworkManager-glib-0.7.0-10.el5_5.2
perl-XML-NamespaceSupport-1.09-1.2.1
perl-XML-Filter-BufferText-1.01-1.2.el5.rf
perl-XML-Simple-2.14-4.fc6
rsnapshot-1.3.1-1.el5.rf

List the files and state the installed version of the package called package. Example

[root@server2 ~]# rpm -ql mysql-5.0.77-4.el5_5.5

Sample outputs:

/etc/ld.so.conf.d/mysql-i386.conf
/etc/my.cnf
/usr/bin/msql2mysql
/usr/bin/my_print_defaults
/usr/bin/mysql
/usr/bin/mysql_config
/usr/bin/mysql_find_rows
/usr/bin/mysql_tableinfo
/usr/bin/mysql_waitpid
/usr/bin/mysqlaccess
/usr/bin/mysqladmin
/usr/bin/mysqlbinlog
/usr/bin/mysqlcheck
/usr/bin/mysqldump
/usr/bin/mysqlimport
/usr/bin/mysqlshow
/usr/lib/mysql

Read the man page

[root@server2 ~]# man rpm

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yum is an interactive, automated update program which can be used for maintaining systems using rpm.

Synopsis

yum [options] [command] [package ...]

The following is a list of the most commonly used yum commands:

Install a package

yum install [package name]

Used to install the latest version of a package or group of packages. If no package matches the specified package name(s), they are assumed to be a shell glob, and any matches are then installed.

Update the specified packages

yum update [package name]

Used to update the specified packages to the latest available version. If no package name/s are specified, then yum will attempt to update all installed packages.

Check update

yum check-update

This command allows you to determine whether any updates are available for your installed packages. yum returns a list of all package updates from all repositories if any are available.

Remove a package

yum remove [package name]

Used to remove specified packages, along with any other packages dependent on the packages being removed.

Determine which packages provide a specific file or feature

yum provides [file name]

Find any packages containing the specified keyword

yum search [keyword]

This command is used to find any packages containing the specified keyword in the description, summary, packager and package name fields of RPMs in all repositories.

For a complete list of available yum commands, refer to man yum.

man yum

Sample outputs:

NAME
       yum - Yellowdog Updater Modified

SYNOPSIS
       yum [options] [command] [package ...]

DESCRIPTION
       yum  is an interactive, rpm based, package manager. It can automatically perform system updates, including dependency analysis and obsolete pro-
       cessing based on "repository" metadata. It can also perform installation of new packages, removal of old packages and  perform  queries  on  the
       installed  and/or  available  packages  among many other commands/services (see below). yum is similar to other high level package managers like
       apt-get and smart.

       While there are some graphical interfaces directly to the yum code, more recent graphical interface development is happening with PackageKit and
       the gnome-packagekit application.

       command is one of:
        * install package1 [package2] [...]
        * update [package1] [package2] [...]
        * check-update
        * upgrade [package1] [package2] [...]
        * remove | erase package1 [package2] [...]
        * list [...]
        * info [...]
        * provides | whatprovides feature1 [feature2] [...]
        * clean [ packages | headers | metadata | dbcache | all ]
        * makecache
        * groupinstall group1 [group2] [...]
        * groupupdate group1 [group2] [...]
        * grouplist [hidden] [groupwildcard] [...]
        * groupremove group1 [group2] [...]
        * groupinfo group1 [...]
        * search string1 [string2] [...]
        * shell [filename]
        * resolvedep dep1 [dep2] [...]
        * localinstall rpmfile1 [rpmfile2] [...]
        * localupdate rpmfile1 [rpmfile2] [...]
...

Example: Install LAMP with single command by yum

Enter the following command:

yum install httpd mysql mysql-server php 

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iptables is a user space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall (implemented as different Netfilter modules) and the chains and rules it stores. Different kernel modules and programs are currently used for different protocols; iptables applies to IPv4, ip6tables to IPv6, arptables to ARP, and ebtables for Ethernet frames.
Iptables requires elevated privileges to operate and must be executed by user root, otherwise it fails to function. On most Linux systems, iptables is installed as /usr/sbin/iptables and documented in its man page,[2] which can be opened using man iptables when installed. It may also be found in /sbin/iptables, but since iptables is not an “essential binary”, but more like a service, the preferred location remains /usr/sbin.
iptables is also commonly used to inclusively refer to the kernel-level components. x_tables is the name of the kernel module carrying the shared code portion used by all four modules that also provides the API used for extensions; subsequently, Xtables is more or less used to refer to the entire firewall (v4,v6,arp,eb) architecture.
Source: http://en.wikipedia.org/wiki/Iptables

In most Linux distros including Redhat / CentOS Linux installs iptables by default. You can use the following procedure to verify that iptables has been installed. Open terminal and type the following command:

root@longvnit:~# iptables -V

Sample outputs:

iptables v1.3.5

You can use the following command to view the status of iptables command, enter:

root@longvnit:~#yum info iptables

Sample outputs:

Installed Packages
Name       : iptables
Arch       : i386
Version    : 1.3.5
Release    : 5.3.el5_4.1
Size       : 552 k
Repo       : installed
Summary    : Tools for managing Linux kernel packet filtering capabilities.
URL        : http://www.netfilter.org/
License    : GPL
Description: The iptables utility controls the network packet filtering code in
           : the Linux kernel. If you need to set up firewalls and/or IP
           : masquerading, you should install this package.

If the above message does not appear, then type the following command to install iptables

root@longvnit:~#yum install iptables

You can use the following command to view rules in all chains:

root@longvnit:~#iptables -L -n

Sample outputs:

Chain INPUT (policy DROP)
target     prot opt source               destination         
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           state RELATED,ESTABLISHED 
ACCEPT     all  --  0.0.0.0/0            0.0.0.0/0           

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination         

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

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PHP: Hypertext Preprocessor is a widely used, general-purpose scripting language that was originally designed for web development to produce dynamic web pages. For this purpose, PHP code is embedded into the HTML source document and interpreted by a web server with a PHP processor module, which generates the web page document. As a general-purpose programming language, PHP code is processed by an interpreter application in command-line mode performing desired operating system operations and producing program output on its standard output channel. It may also function as a graphical application. PHP is available as a processor for most modern web servers and as a standalone interpreter on most operating systems and computing platforms. (wikipedia.org)

PHP works with apache, lighttpd, nignx and other webservers and PHP is very easy to install.

Installing PHP on CentOS

if you would like to install PHP on CentOS use yum command

yum install php

Updating PHP on CentOS

if you would like to update PHP on CentOS use yum command

yum update php

Install & Update PHP latest version

Default the system will be installed php with stable version, but if you wanted to install or update PHP with latest version then you need to create /etc/yum.repos.d/centos-test.repo and enter following lines in it:

[c5-testing]
name=CentOS-5 Testing
baseurl=http://dev.centos.org/centos/5/testing/$basearch/
enabled=1
gpgcheck=1
gpgkey=http://dev.centos.org/centos/RPM-GPG-KEY-CentOS-testing

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