[2.0a1] After upgrade form 1.10, dhcpd is enabled on wrong interface

[Andres Rodriguez]

dhcpd.conf can be found in: http://paste.ubuntu.com/15270493/
dhcpd-interfaces has virbr2 instead of virbr0

#syslog:

Mar 2 17:57:10 unleashed maas.service_monitor: [INFO] Service 'maas-dhcpd' has been started and is 'running'.
Mar 2 17:57:10 unleashed dhcpd[31420]: Wrote 0 class decls to leases file.
Mar 2 17:57:10 unleashed dhcpd[31420]: Wrote 0 deleted host decls to leases file.
Mar 2 17:57:10 unleashed dhcpd[31420]: Wrote 0 new dynamic host decls to leases file.
Mar 2 17:57:10 unleashed dhcpd[31420]: Wrote 1 leases to leases file.
Mar 2 17:57:10 unleashed dhcpd[31420]:
Mar 2 17:57:10 unleashed dhcpd[31420]: No subnet declaration for virbr2 (192.168.133.1).
Mar 2 17:57:10 unleashed dhcpd[31420]: ** Ignoring requests on virbr2. If this is not what
Mar 2 17:57:10 unleashed dhcpd[31420]: you want, please write a subnet declaration
Mar 2 17:57:10 unleashed dhcpd[31420]: in your dhcpd.conf file for the network segment
Mar 2 17:57:10 unleashed dhcpd[31420]: to which interface virbr2 is attached. **
Mar 2 17:57:10 unleashed dhcpd[31420]:
Mar 2 17:57:10 unleashed dhcpd[31420]:
Mar 2 17:57:10 unleashed dhcpd[31420]: Not configured to listen on any interfaces!
Mar 2 17:57:10 unleashed dhcpd[31420]:
Mar 2 17:57:10 unleashed dhcpd[31420]: If you think you have received this message due to a bug rather
Mar 2 17:57:10 unleashed dhcpd[31420]: than a configuration issue please read the section on submitting
Mar 2 17:57:10 unleashed dhcpd[31420]: bugs on either our web page at www.isc.org or in the README file
Mar 2 17:57:10 unleashed dhcpd[31420]: before submitting a bug. These pages explain the proper
Mar 2 17:57:10 unleashed dhcpd[31420]: process and the information we find helpful for debugging..
Mar 2 17:57:10 unleashed dhcpd[31420]:
Mar 2 17:57:10 unleashed dhcpd[31420]: exiting.

[...]

roaksoax@unleashed:/etc/apt/sources.list.d⟫ sudo service maas-dhcpd status
● maas-dhcpd.service - MAAS instance of ISC DHCP server for IPv4
   Loaded: loaded (/lib/systemd/system/maas-dhcpd.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Wed 2016-03-02 17:59:50 EST; 1min 7s ago
     Docs: man:dhcpd(8)
  Process: 2006 ExecStart=/bin/sh -ec INTERFACES=$(cat /var/lib/maas/dhcpd-interfaces); LEASES_FILE=/var/lib/maas/dhcp/dhcpd.leases;
  Process: 2002 ExecStartPre=/bin/chown root:root /var/lib/maas/dhcp (code=exited, status=0/SUCCESS)
  Process: 1998 ExecStartPre=/bin/mkdir -p /var/lib/maas/dhcp (code=exited, status=0/SUCCESS)
  Process: 1993 ExecStartPre=/bin/chown root:root /run/maas/dhcp (code=exited, status=0/SUCCESS)
  Process: 1988 ExecStartPre=/bin/mkdir -p /run/maas/dhcp (code=exited, status=0/SUCCESS)
 Main PID: 2006 (code=exited, status=1/FAILURE)

Mar 02 17:59:49 unleashed systemd[1]: Starting MAAS instance of ISC DHCP server for IPv4...
Mar 02 17:59:49 unleashed systemd[1]: Started MAAS instance of ISC DHCP server for IPv4.
Mar 02 17:59:49 unleashed dhcpd[2006]: Wrote 0 class decls to leases file.
Mar 02 17:59:49 unleashed dhcpd[2006]: Wrote 0 deleted host decls to leases file.
Mar 02 17:59:49 unleashed dhcpd[2006]: Wrote 0 new dynamic host decls to leases file.
Mar 02 17:59:49 unleashed dhcpd[2006]: Wrote 1 leases to leases file.
Mar 02 17:59:50 unleashed systemd[1]: maas-dhcpd.service: Main process exited, code=exited, status=1/FAILURE
Mar 02 17:59:50 unleashed systemd[1]: maas-dhcpd.service: Unit entered failed state.
Mar 02 17:59:50 unleashed systemd[1]: maas-dhcpd.service: Failed with result 'exit-code'.

[Andres Rodriguez (andreserl)]

interfaces read of rack controller: http://paste.ubuntu.com/15270528/

[Andres Rodriguez (andreserl)]

ip addr http://paste.ubuntu.com/15270529/

[Andres Rodriguez (andreserl)]

Ok, so I tried a different thing.

1. Installed fresh MAAS on my same systems
2. Configured DHCP for an untagged VLAN, that was providing DHCP for subent 192.168.122.0/24.
3. dhcpd.conf -> http://paste.ubuntu.com/15271300/
4. dhcpd-interfaces -> http://paste.ubuntu.com/15271302/

If you see 4, dhcpd-interfaces has the incorrect interface. This bug is present on both fresh installs and upgrades.

[Andres Rodriguez (andreserl)]

So I looked into the code and into the get_interfaces_with_ip_on_vlan and I see that this is wrong. I put a logger function to show what interfaces were being returned for that particular VLAN, and I found this:

Mar 2 21:06:45 unleashed maas.dhcp: [WARNING] ##### Interfaces with ip on VLAN: fabric-3.untagged Interfaces: name=virbr1, type=physical, mac=52:54:00:c2:29:bb
Mar 2 21:06:45 unleashed maas.dhcp: [WARNING] ##### Interfaces with ip on VLAN: fabric-3.untagged Interfaces: name=virbr0, type=physical, mac=52:54:00:d3:1a:ac
Mar 2 21:06:45 unleashed maas.dhcp: [WARNING] ##### Interfaces with ip on VLAN: fabric-3.untagged Interfaces: name=virbr2, type=physical, mac=52:54:00:df:e7:1c
Mar 2 21:06:45 unleashed maas.dhcp: [WARNING] ##### Interfaces with ip on VLAN: fabric-3.untagged Interfaces: name=lxcbr0, type=physical, mac=92:35:cf:fd:2e:8b
Mar 2 21:06:45 unleashed maas.dhcp: [WARNING] ##### Interfaces with ip on VLAN: fabric-3.untagged Interfaces: name=wlan0, type=physical, mac=7c:7a:91:40:48:4f
Mar 2 21:06:45 unleashed maas.dhcp: [WARNING] ##### Interfaces with ip on VLAN: fabric-3.untagged Interfaces: name=eth0, type=physical, mac=28:d2:44:65:25:55

In reality, it is returning all interfaces on all VLAN's, even though it should only be returning interfaces on fabric-3.untagged VLAN, which in reality is only 1. virbr0. In this case, it seems to be incorrectly "finding" multiple interfaces on fabric-3.untagged. That being said, however, it seems to later on have just picked virbr1 as it was the first one.