= Yum groups and repositories =

'''Note that this page is out of date, and refers to how yum acted before the "yum groups" sub-command and the group_command configuration feature were added.'''

Yum supports the group commands
  * grouplist
  * groupinfo
  * groupinstall
  * groupremove
  * groupupdate

Groups are read from the "group" xml metadata that is optionally available from
each repository. If yum has no repositories which support groups then none of 
the group operations will work. 


 * grouplist
   {{{
      yum grouplist [hidden]
   }}}
   
   This will list the installed and available groups for your system in two
   separate lists. If you pass the optional 'hidden' argument then all of 
   the groups which are set to 'no' in the group xml <uservisible> tag.

 * groupinfo
  {{{ 
     yum groupinfo groupname
  }}}
  
  This will give you detailed information for each group including:
  description, mandatory, default and optional packages.

 * groupinstall, groupupdate
  {{{ 
     yum groupinstall groupname
     yum groupupdate groupname
  }}}

  Despite their differing names both of these commands perform the same
  function. They will attempt to install/update all of the packages in the
  group that are of the types 'default' or 'mandatory' (by default).
  (To change this types of packages edit the value of the group_package_types 
  option in yum.conf.) And they will install any additional dependencies 
  needed by any of the installing/updating packages.

 * groupremove
  {{{
     yum groupremove groupname
  }}}
  
  This will remove all packages, of any type, in the named group. It will also
  remove any package that depends on any of these packages.
   


== Setting up your own groups in your own repository ==

This process is pretty easy, just two steps:
 1. create a file in the groups format used by yum
 2. tell createrepo to include that group file in your repository.


=== Step 1 ===
  You can either open a text editor and create the groups xml file manually or you
  can run the yum-groups-manager command from yum-utils. 

  Run the groups-create command like this:
    {{{
       yum-groups-manager -n "My Group" --id=mygroup --save=mygroups.xml --mandatory yum glibc rpm
    }}}

And you'll end up with a file like this:

{{{
<!DOCTYPE comps PUBLIC "-//Red Hat, Inc.//DTD Comps info//EN" "comps.dtd">
<comps>
  <group>
   <id>mygroup</id>
   <default>False</default>
   <uservisible>True</uservisible>
   <display_order>1024</display_order>
   <name>My group</name>
   <description></description>
    <packagelist>
      <packagereq type="mandatory">glibc</packagereq>
      <packagereq type="mandatory">rpm</packagereq>
      <packagereq type="mandatory">yum</packagereq>
    </packagelist>
  </group>
</comps>
}}}


=== Step 2 ===
  To include this in a repository, just tell [http://createrepo.baseurl.org/ createrepo] to use it when making or remaking
  your repository.

  {{{ 
     createrepo -g /path/to/mygroups.xml /srv/my/repo
  }}}