Installing ejabberd2 on CentOS and configure a virtual host on Apache2

1. Enable epel yum repository

Centos 5.x

wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm
sudo rpm -Uvh epel-release-5*.rpm

Centos 6.x

wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
sudo rpm -Uvh epel-release-6*.rpm

2. Install ejabberd2

yum --enablerepo=epel install ejabberd

3. Start the ejabberd2 service

service ejabberd start

4. Edit the virtual hosts configuration file and add

  ProxyPass /http-bind  http://127.0.0.1:5280/http-bind/
  ProxyPassReverse  /http-bind   http://127.0.0.1:5280/http-bind/
  Header set Access-Control-Allow-Origin "YOUR_VIRTUAL_SERVER_HOSTNAME"

(please note that using "Header set Access-Control-Allow-Origin" enables Cross-origin resource sharing and using a wildcard as origin should not normally be used)

This is generally not appropriate. The only case where this is appropriate is when a page or api response is considered completely public content and it is intended to be accessible to browsable to everyone. Including any code on any site.
(http://en.wikipedia.org/wiki/Cross-origin_resource_sharing)

5. Test configuration

service httpd configtest

6. Reload apache configuration

service httpd reload

Since ejabberd comes with http-bind enabled out of the box
 

{5280, ejabberd_http, [
 %%{request_handlers,
 %% [
 %%  {["pub", "archive"], mod_http_fileserver}
 %% ]},
 captcha,
 http_bind,
 http_poll,
 %%register,
 web_admin
]}

you should now be able to access the XMPP over BOSH (XEP-0206) server in your browser looking somewhat like below.