Foreman » Smart Proxy

DHCP uses a last-lease-wins system - new leases are appended to the leases file and automatically are preferred over earlier entries. However, the proxy uses a first-lease-wins, where we discard any leases that we already have in memory when parsing the leases file.

When you have a lease file like this:

lease 192.168.123.58 {
  starts 5 2014/05/09 14:38:13;
  ends 5 2014/05/09 14:48:13;
  cltt 5 2014/05/09 14:38:13;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 52:54:00:22:17:2b;
  uid "\001RT\000\"\027+";
}
lease 192.168.123.59 {
  starts 5 2014/05/09 14:39:00;
  ends 5 2014/05/09 14:49:00;
  cltt 5 2014/05/09 14:39:00;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 52:54:00:22:17:2b;
}
lease 192.168.123.59 {
  starts 5 2014/05/09 14:39:12;
  ends 5 2014/05/09 14:49:12;
  cltt 5 2014/05/09 14:39:12;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 52:54:00:22:17:2b;
}

Then the proxy would report that /dhcp/192.168.123.0/52:54:00:22:17:2b has IP 192.168.123.58 - when in actual fact it has 192.168.123.59.

We need to rewire the proxy to replace leases in memory as it parses down the file.