====== Local Red Hat repository ======

Download and Install mrepo RPM from
http://pkgs.repoforge.org/mrepo/

  yum localinstall --nogpgcheck mrepo-0.8.8-0.pre1.el6.rft.noarch.rpm

Edit /etc/mrepo.conf to suit your needs:

  ### Configuration file for mrepo
  ### The [main] section allows to override mrepo's default settings\\
  ### The mrepo-example.conf gives an overview of all the possible settings\\
  [main]
  srcdir = /var/www/html/yum/mrepo
  wwwdir = /var/www/html/yum/repo
  confdir = /etc/mrepo.conf.d
  arch =  x86_64
  # Default is sha256. RHEL5 requires sha1 (parameter is then sha)
  createrepo-options = --checksum sha

Add /etc/mrepo.conf.d/rhel-5Server.conf to suit your needs:

  [rhel-5Server]
  name = Red Hat Enterprise Linux Server $release ($arch)
  release = 5
  arch = x86_64
  metadata = yum repomd repoview
  updates = rhns:///rhel-$arch-server-5
  custom =

Add /etc/mrepo.conf.d/rhel-6Server.conf to suit your needs:

  [rhel-6Server]
  name = Red Hat Enterprise Linux Server $release ($arch)
  release = 6
  arch = x86_64
  metadata = yum repomd repoview
  updates = rhns:///rhel-$arch-server-6
  custom =

Run mrepo to generate files/directories
  
  mrepo -vvvvugf

If following error is encountered:

No rhnuuid config option found in /etc/sysconfig/rhn/up2date-uuid.

Run following command:
  # UUID=$(uuidgen) ; /bin/echo -e "uuid[comment]=Universally Unique ID for this server\nrhnuuid=$UUID" > /etc/sysconfig/rhn/up2date-uuid

Generate system ID's and register local repo with RHN:
  # gensystemid -r 6Server -a x86_64 /var/www/html/yum/mrepo/rhel-6Server-x86_64
  RHN Username: <Supply RHN username>
  RHN Password: <Supply RHN password>
  Writing out file....

  # gensystemid -r 5Server -a x86_64 /var/www/html/yum/mrepo/rhel-5Server-x86_64
  RHN Username: <Supply RHN username>
  RHN Password: <Supply RHN password>
  Writing out file....

Fix user rights so Apache can read files:
  chmod 755 -R /var/www/html/yum/mrepo/
  chmod 755 -R /var/www/html/yum/repo/
  
 
Run mrepo again to download all rpm files from RHN
  mrepo -vvvvug

Web-server:
Add /etc/httpd/conf.d/yum-repository.conf:

  NameVirtualHost <mrepo-server IP>
  <VirtualHost <mrepo-server IP>>
        ServerName yum-repository
        DocumentRoot /var/www/html/yum/
        <Directory "/var/www/html/yum">
                Options Indexes FollowSymLinks MultiViews
                IndexOptions FancyIndexing
                Order allow,deny
                Allow from all
        </Director>
        CustomLog /var/log/httpd/yum-repository.access.log combined
        ErrorLog /var/log/httpd/yum-repository.error.log
  </VirtualHost>                                                

Add a entry to crontab in order to update repositories from RHN on a regular basis. Schedule should be configures to suit your needs
/etc/cron.montly/mrepoupdate:

  #!/bin/bash
  /usr/bin/mrepo -q -ug  


In order to let clients use the repo, do following client configuration:

/etc/yum/yum.repos.d/rhel.repo
  [rhel-repo]
  name=Red Hat Enterprise Linux $releasever - $basearch
  baseurl=http://<mrepo-server IP>/repo/rhel-$releasever-$basearch/RPMS.updates
  enabled=1
  gpgcheck=1
  gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release

Disable RHN:
  /etc/yum/pluginconf.d/rhnplugin.conf
  enabled = 0

====== Kickstart install from mrepo ======


Prepare group file.
Copy group file from RHEl5/6 DVD to $srcdir/<reponame>_arch directory. The file should be called <nameofrepo>-comps.xml. RPMS.<nameofrepo> should lead you to the right place. Source Group file can be found on RHEL DVD under Server/repodata directory.

RHEL5 groupfile. Same file with two different names. Hence the RPMS.all and RPMS.updates directory.

  /var/www/html/yum/mrepo/rhel-5Server-x86_64/all-comps.xml
  /var/www/html/yum/mrepo/rhel-5Server-x86_64/updates-comps.xml

This will generate RHEL5 group metadata (xml) in:

  /var/www/html/yum/repo/rhel-5Server-x86_64/RPMS.all/repodata/
  /var/www/html/yum/repo/rhel-5Server-x86_64/RPMS.updates/repodata/

RHEL6:

RHEL6 groupfile. Same file with two different names. Hence the RPMS.all and RPMS.updates directory.

  /var/www/html/yum/mrepo/rhel-6Server-x86_64/all-comps.xml
  /var/www/html/yum/mrepo/rhel-6Server-x86_64/updates-comps.xml

This will generate RHEL6 group metadata (xml) in:

  /var/www/html/yum/repo/rhel-6Server-x86_64/RPMS.updates/repodata 
  /var/www/html/yum/repo/rhel-6Server-x86_64/RPMS.all/repodata

RHEL5 is expecting installation tree to be in a subfolder called Server.

Make softlink to Server directory:

RHEL5:

  cd /var/www/html/yum/repo/rhel-5Server-x86_64
  ln -s RPMS.all Server
  
RHEL6:

  Softlink N/A
  
To use your http repo add following to the beginning of your kickstart file.


RHEL5:
  install
  url --url http://<IP of Web(REPO) server>/repo/rhel-5Server-x86_64


RHEL6:
  install
  url --url http://<IP of Web(REPO) server>/repo/rhel-6Server-x86_64/RPMS.all


References\\
http://igrelease.forge.cnaf.infn.it/doku.php?id=doc:tips:mrepo\\
http://www.labmonkeys.org/sysadmin/rpm/installing_mrepo_on_rhel5\\
http://www.brandonhutchinson.com/mrepo_configuration.html\\
http://lists.repoforge.org/pipermail/tools/2008-November/001368.html