app_dhcpd.cf

bundle agent app_dhcpd
{
  classes:

     "any" expression => regextract(
                                "([^\n]+)\.([^\n]+)\.([^\n]+)",
                               "$(sys.ipv4_3[eth0])",
                               "ip_addr"
                              );

  vars:
      "repo" string => "/var/cfengine/configfiles";

    fs::
      "install_packages" slist => {
                                    "dhcp-server"
                                  };

      "svc_states[dhcpd]" string => "on";
      "services" slist => getindices("svc_states");

      "dns_server_to_update" string => "127.0.0.1", policy => "overridable";

      "reverse_zone_to_update" string => "$(app_dhcpd.ip_addr[3]).$(app_dhcpd.ip_addr[2]).$(app_dhcpd.ip_addr[1])";

    fs_vircio_com::
      "dns_server_to_update" string => "10.1.7.4";


    fs::
      "dhcpd_conf" string =>
"# This file is generated by CFEngine.                                                                                  
                                                                                                                        
ddns-domainname \"$(sys.domain)\";                                                                                      
ddns-updates off;                                                                                                       
ddns-update-style interim;                                                                                              
include \"/etc/rndc.key\";                                                                                              
                                                                                                                        
zone $(sys.domain). {                                                                                                   
  primary $(dns_server_to_update);                                                                                      
  key rndc-key;                                                                                                         
}                                                                                                                       
                                                                                                                        
zone $(reverse_zone_to_update).in-addr.arpa. {                                                                          
  primary $(dns_server_to_update);                                                                                      
  key rndc-key;                                                                                                         
}                                                                                                                       
                                                                                                                        
                                                                                                                        
                                                                                                                        
# EOF                                                                                                                   
";

 packages:
    SuSE::
      "$(install_packages)"
      comment => "Install base packages.",
      package_policy => "add",
      package_method => zypper;

  methods:
      "any" usebundle => service_startup("$(services)","$(svc_states[$(services)])");

  files:
    fs::
      "/etc/sysconfig/dhcpd"
      comment => "Bind dhcpd to eth0 and include files",
      edit_line => replace_or_add("DHCPD_INTERFACE=\"\"","DHCPD_INTERFACE=\"eth0\"");

      "/etc/dhcpd.conf"
      comment => "Generate the dhcpd.conf",
      edit_line => append_if_no_line("$(dhcpd_conf)"),
      edit_defaults => empty,
      classes => if_repaired("restart_dhcpd");

      "/etc/dhcpd.d/dhcpd-leases.conf"
      comment => "Copy dhcpd-leases.conf from the central repository",
      copy_from => secure_cp("$(repo)/etc/dhcpd.d/dhcpd-leases.conf.$(sys.fqhost)","$(sys.policy_hub)"),
      perms => mog("0644", "root", "root"),
      classes => if_repaired("restart_dhcpd");
}


Output from this policy...
# This file is generated by CFEngine.

ddns-domainname "vircio.com";
ddns-updates off;
ddns-update-style interim;
include "/etc/rndc.key";

zone vircio.com. {
  primary 10.1.7.4;
  key rndc-key;
}

zone $(app_dhcpd.ip_addr[3]).$(app_dhcpd.ip_addr[2]).$(app_dhcpd.ip_addr[1]).in-addr.arpa. {
  primary 10.1.7.4;
  key rndc-key;
}



# EOF