Install Apache Web Server CentOS 7

 In this chapter, we will learn a little about the background of how Apache HTTP Server came into existence and then install the most current stable version on CentOS Linux 7.

Brief History on Apache WebServer

Apache is a web server that has been around for a long time. In fact, almost as long as the existence of http itself!

Apache started out as a rather small project at the National Center for Supercomputing Applications also known as NCSA. In the mid-90's "httpd", as it was called, was by far the most popular web-server platform on the Internet, having about 90% or more of the market share.

At this time, it was a simple project. Skilled I.T. staff known as webmaster were responsible for: maintaining web server platforms and web server software as well as both front-end and back-end site development. At the core of httpd was its ability to use custom modules known as plugins or extensions. A webmaster was also skilled enough to write patches to core server software.

Sometime in the late-mid-90's, the senior developer and project manager for httpd left NCSA to do other things. This left the most popular web-daemon in a state of stagnation.

Since the use of httpd was so widespread a group of seasoned httpd webmasters called for a summit reqarding the future of httpd. It was decided to coordinate and apply the best extensions and patches into a current stable release. Then, the current grand-daddy of http servers was born and christened Apache HTTP Server.

Little Known Historical Fact − Apache was not named after a Native American Tribe of warriors. It was in fact coined and named with a twist: being made from many fixes (or patches) from many talented Computer Scientists: a patchy or Apache.

Install Current Stable Version on CentOS Linux 7

Step 1 − Install httpd via yum.

yum -y install httpd

At this point Apache HTTP Server will install via yum.

Step 2 − Edit httpd.conf file specific to your httpd needs.

With a default Apache install, the configuration file for Apache is named httpd.conf and is located in /etc/httpd/. So, let's open it in vim.

The first few lines of httpd.conf opened in vim −

# 
# This is the main Apache HTTP server configuration file.  It contains the 
# configuration directives that give the server its instructions.
# See <URL:http://httpd.apache.org/docs/2.4/> for detailed information. 
# In particular, see  
# <URL:http://httpd.apache.org/docs/2.4/mod/directives.html> 
# for a discussion of each configuration directive.

We will make the following changes to allow our CentOS install to serve http requests from http port 80.

Listening host and port

# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the <VirtualHost>
# directive.
#
# Change this to Listen on specific IP addresses as shown below to
# prevent Apache from glomming onto all bound IP addresses.
#
#Listen 12.34.56.78:80
Listen 80

From here, we change Apache to listen on a certain port or IP Address. For example, if we want to run httpd services on an alternative port such as 8080. Or if we have our web-server configured with multiple interfaces with separate IP addresses.

Listen

Keeps Apache from attaching to every listening daemon onto every IP Address. This is useful to stop specifying only IPv6 or IPv4 traffic. Or even binding to all network interfaces on a multi-homed host.

#
# Listen: Allows you to bind Apache to specific IP addresses and/or
# ports, instead of the default. See also the <VirtualHost>
# directive.
#
# Change this to Listen on specific IP addresses as shown below to
# prevent Apache from glomming onto all bound IP addresses.
#
Listen 10.0.0.25:80
#Listen 80

DocumentRoot

The "document root" is the default directory where Apache will look for an index file to serve for requests upon visiting your sever: http://www.yoursite.com/ will retrieve and serve the index file from your document root.

#
# DocumentRoot: The directory out of which you will serve your
# documents. By default, all requests are taken from this directory, but
# symbolic links and aliases may be used to point to other locations.
#
DocumentRoot "/var/www/html"

Step 3 − Start and Enable the httpd Service.

[root@centos rdc]# systemctl start httpd && systemctl reload httpd 
[root@centos rdc]#

Step 4 − Configure firewall to allow access to port 80 requests.

[root@centos]# firewall-cmd --add-service=http --permanent