Setting Up LAMP Stack On CentOS and RackSpace Cloud Server

Posted Dec 30, 2010 // 6 comments

The following is a step-by-step guide for setting up and configuring a LAMP Stack on a 1GB or 2GB RackSpace Cloud Server with the latest CentOS distribution. You will need root access to complete the following steps.

Please note that in these instructions I make the specific effort of installing PHP 5.2, which is still the most compatible/safest PHP version for running Drupal.

Linux Bootstrap

• Log in as root
• Set the hostname
  • sudo hostname yourdomain.com
  • Add entry into /etc/hosts:
  • _public ip address_ yourdomain.com
  • Edit /etc/sysconfig/network to set hostname
  • Check /proc/sys/kernel/hostname for hostname
• A reboot might be necessary (might as well)
• Set root password to something that is impossible to remember.
• Setup sudo, if it is not already set up (typically it is)
• sudo groupadd sudoers
• sudo groupadd webmaster
• In /etc/bashrc set umask to 0002
• Create a local account (regular user with primary group set to webmaster and secondary group to sudoers)
• useradd -m -s /bin/bash -g webmaster -G sudoers irakli
• Set local account’s password:
• passwd irakli

• Log in as the local account (“irakli” in our examples).

The rest of the tutorial assumes you are working with the local account and sudo into root as necessary.

Configuring Yum

• sudo rpm -Uvh http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/epel-release-1-1.ius.el5.noarch.rpm

• sudo rpm -Uvh http://dl.iuscommunity.org/pub/ius/stable/Redhat/5/x86_64/ius-release-1.0-6.ius.el5.noarch.rpm

For more information about setting up Rackspace’s IUS Community repository, please refer to the following blog post: Reliable Yum Repo for Easy Upgrades to the Latest Packages, on RedHat and CentOS

Setting Up Packages

• sudo yum install openssl-devel zlib-devel gcc gcc-c++ make autoconf readline-devel curl-devel expat-devel gettext-devel
• sudo yum install libjpeg libpng telnet libxslt freetype freetype-devel
• sudo yum install mysql51-server mysql51-devel
• sudo yum install php52-devel httpd-devel apr-devel
• sudo yum install php52-pear
• sudo yum install mod_ssl
• sudo yum install php52-mysql php52-gd php52-xml php52-mbstring php52-mcrypt
• sudo yum install php52-pecl-apc edit /etc/php.d/apc.ini and enter:

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  extension=apc.so apc.enabled=1 apc.shm_segments=1 apc.shm_size=64 apc.ttl=7200 apc.user_ttl=7200 apc.num_files_hint=1024 apc.mmap_file_mask=/tmp/apc.XXXXXX apc.enable_cli=1

• sudo yum install bind bind-utils bind-devel

• sudo yum install postfix openssl

VirtualHost Configuration

• sudo mkdir /var/www/vhosts
• sudo mkdir /var/www/default
• sudo vi /etc/httpd/conf.d/00_default.virtualhost.conf and in there enter:

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  NameVirtualHost *:80   <VirtualHost *:80>     ServerAdmin webmaster@example.com     DocumentRoot /var/www/default     ServerName __default__     ErrorLog logs/default-error_log     CustomLog logs/default-access_log common </VirtualHost>

• sudo vi /var/www/default/index.html
in there enter any text, e.g.: “RESTRICTED”.
• in /etc/httpd/conf/httpd.conf replace all /var/www/html with var/www/vhosts
  • change “KeepAlive Off” to “KeepAlive On”
  • change “KeepAliveTimeout” from 15 to 5
• Uncomment and Add ServerName yourdomain.com
• type following:

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  cd /var/www/vhosts/  sudo chown -R apache:apache .  sudo chmod -R 775 /var/www/vhosts

• Make apache-owned files writable by your local user (“irakli” in our examples): sudo /usr/sbin/usermod -G sudoers,apache irakli
• sudo mkdir -p /var/www/vhosts/yourdomain.com/html
• sudo mkdir -p /var/www/vhosts/yourdomain.com/logs
• sudo vi /etc/httpd/conf.d/yourdomain.com.conf

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  <VirtualHost *:80>     ServerAdmin webmaster@yourdomain.com     DocumentRoot /var/www/vhosts/yourdomain.com/html     ServerName yourdomain.com     ServerAlias subdomain.yourdomain.com     ErrorLog /var/www/vhosts/yourdomain.com/logs/error_log     CustomLog /var/www/vhosts/yourdomain.com/logs/access_log combined       UseCanonicalName Off      <Directory /var/www/vhosts/yourdomain.com/html>         AllowOverride all         Options all         Order allow,deny         Allow from all         Deny from none         # Insert filter           SetOutputFilter DEFLATE             # Netscape 4.x has some problems…           BrowserMatch ^Mozilla/4 gzip-only-text/html             # Netscape 4.06-4.08 have some more problems           BrowserMatch ^Mozilla/4\.0[678] no-gzip             # NOTE: Due to a bug in mod_setenvif up to Apache 2.0.48           # the above regex won't work. You can use the following           # workaround to get the desired effect:           BrowserMatch \bMSI[E] !no-gzip !gzip-only-text/html             # Don't compress images, videos and audio           SetEnvIfNoCase Request_URI \           \.(?:gif|jpe?g|png|flv|mp4|m4v|mp3|zip|gz)$ no-gzip dont-vary             # Make sure proxies don't deliver the wrong content           Header append Vary User-Agent env=!dont-vary        </Directory>   FileETag none   </VirtualHost>

  Please do not forget to replace “yourdomain.com” with the actual domain name you are setting up, in the above example code.
• cd /var/www/vhosts
• sudo chown -R apache:apache /var/www/vhosts
• sudo chmod -R 775 /var/www/vhosts
• sudo /etc/init.d/httpd configtest

• sudo /etc/init.d/httpd restart

Apache Caching of Resources

If the website you are deploying is not a Drupal site, make sure to add the following inside the VirtualHost:

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ExpiresActive On
ExpiresDefault "access plus 2 minutes"
ExpiresByType image/gif A2592000
ExpiresByType image/jpeg A2592000
ExpiresByType image/png A2592000
ExpiresByType text/css A2592000
ExpiresByType application/x-javascript A2592000
ExpiresByType text/javascript A2592000
ExpiresByType application/x-shockwave-flash A2592000

You do not need to do this for Drupal. Drupal already does these in .htaccess, but Joomla, for instance, may not.

Configure Firewall

• Edit /etc/sysconfig/iptables-config and make sure following variables are set to “yes”:
  • IPTABLES_SAVE_ON_STOP=“yes”
• IPTABLES_SAVE_ON_RESTART=“yes”
• Open Web ports:
• sudo /sbin/iptables -I INPUT -p tcp -m state --state NEW,ESTABLISHED --dport 80 -j ACCEPT
• sudo /sbin/iptables -I INPUT -p tcp -m state --state NEW,ESTABLISHED --dport 443 -j ACCEPT

• Restart iptables with:

Recommended Settings for Performance Tuning

That said, you are not going to run newsweek.com or huffingtonpost.com on a 1GB or 2GB slice and the default settings are typically so off that it is possible to give you a much better starting point.

Following are some recommended settings that help maximize the utilization of the resources on a multi-core server of 1-2GB RAM size (like that on RackSpace cloud). Please note that these settings are just snippets from the respective configuration files and not the entire configuration file. Do not replace existing files with just these setting, rather edit the new settings into the files already created by previous installation steps.

In /etc/php.ini:

In /etc/my.cnf (warning: a snippet, not a full configuration):

In /etc/httpd/conf/httpd.conf

Disabling Swapping

If you want to be absolutely sure that swapping never happens you can disable swap. This is dangerous because if you don’t properly project your maximum memory allocation you may run out of space and server will crash. But sometimes the risk is worth the benefit of running the server at top speed. To disable swap: edit the /etc/fstab file and find a record that looks like:

The first column shows the partition used for swap: /dev/sda2. It may be different in your case. To disable swap put a comment character (”#” pound character) in front of that line and run the following command as root:

where the argument of “swapoff” should be the partition which swap was mounted on.

Static Cache

Another thing that could be a great idea for a small server is to put it behind a static-HTTP-cache like Varnish. That can really boost your scalability. Configuring Varnish is a complex and large topic that requires its own blog post, however.

Add Startup Scripts

• HTTPD
  • sudo /sbin/chkconfig —add httpd
  • sudo /sbin/chkconfig —level 2345 httpd on

• sudo /sbin/chkconfig —list httpd

• MySQL
  • sudo /sbin/chkconfig —add mysqld
  • sudo /sbin/chkconfig —level 2345 mysqld on

• sudo /sbin/chkconfig —list mysqld