Something

        # If the conf file is inside the  installroot - use that.                                                                                                      
        # otherwise look for it in the normal root                                                                                                                     
        if opts.conffile==None:                                                                                                                                        
            opts.conffile = '/etc/yum/yum.conf'                                                                                                                        
            if os.access(opts.installroot+'/'+opts.conffile, os.R_OK):                                                                                                 
                opts.conffile = opts.installroot+'/'+opts.conffile                                                                                                     
            elif os.access(opts.installroot+'/etc/yum.conf', os.R_OK):                                                                                               
                opts.conffile = opts.installroot+'/etc/yum.conf'
        if opts.installroot:                                                                                                                                           
            root=opts.installroot                                                                                                                                      
        else:                                                                                                                                                          
            root = '/'                                                                                                                                                 
        return root