[Bug 1257082] Re: MAAS does not use NTP servers specified in DHCPD options

[Robie Basak]

If you set NTPDATE_USE_NTP_CONF=no (eg. from a preseed late_command),
then does this fix the issue?

Sounds to me that we either need to have MAAS do that, or consult with
Debian about the intention of this setting and its interaction with DHCP
in the default case to see if it's a bug or it's intentional.

I understand your use case and think that MAAS should support it, but I
wonder whether just fixing the DHCP hook will work in all cases, or some
other work is required here. My doubt is just that DHCP needs to run
much earlier than usual in the cloud-init case, and so I don't know if
the hook will always run, and therefore just want to make sure. Scott?

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Title:
  MAAS does not use NTP servers specified in DHCPD options

Status in MAAS:
  Invalid
Status in “isc-dhcp” package in Ubuntu:
  New
Status in “ntp” package in Ubuntu:
  New

Bug description:
  I have tried setting up NTP servers as DHCP options to MAAS nodes
  because I am behind a proxy here at work that cannot contact
  ntp.ubuntu.com. Here is the top of the dhcpd.conf file on on my MAAS
  head node, maas01:

  root at maas01:/etc/dhcp# less dhcpd.conf
  default-lease-time 600;
  max-lease-time 7200;

  subnet 192.168.0.0 netmask 255.255.0.0 {
    option domain-name "mgmt";
    option domain-name-servers 192.168.255.254;
    option routers 192.168.255.254;

    pool {
      range 192.168.0.1 192.168.255.253;
      deny unknown-clients;
    }
  }

  subnet 10.255.0.0 netmask 255.255.0.0 {
    option domain-name "maas";
    option domain-name-servers 10.255.0.1;
    option routers 10.255.0.1;
    option ntp-servers 172.31.22.1, 172.31.23.1, 172.31.20.104;
    next-server 10.255.0.1;

    pool {
      range 10.255.1.0 10.255.255.254;
      deny unknown-clients;
    }
  }

  I have also verified the parameter is being sent to a client’s DHCP
  lease:

  ubuntu at sled204n0:/var$ cat /var/lib/dhcp/dhclient.eth0.leases
  lease {
    interface "eth0";
    fixed-address 10.255.4.44;
    option subnet-mask 255.255.0.0;
    option routers 10.255.0.1;
    option dhcp-lease-time 600;
    option dhcp-message-type 5;
    option domain-name-servers 10.255.0.1;
    option dhcp-server-identifier 10.255.0.1;
    option ntp-servers 172.31.22.1,172.31.23.1,172.31.20.104;
    option domain-name "maas";
    renew 4 2000/01/06 19:40:51;
    rebind 4 2000/01/06 19:40:51;
    expire 4 2000/01/06 19:40:51;
  }

  Even so, the date on the target node is still incorrect.

  ubuntu at sled204n0:/etc$ date
  Thu Jan  6 19:52:29 UTC 2000

  The ntpdate defaults are the following (unchanged from MAAS defaults):

  ubuntu at sled204n0:/etc$ cat /etc/default/ntpdate
  # The settings in this file are used by the program ntpdate-debian, but not
  # by the upstream program ntpdate.

  # Set to "yes" to take the server list from /etc/ntp.conf, from package ntp,
  # so you only have to keep it in one place.
  NTPDATE_USE_NTP_CONF=yes

  # List of NTP servers to use  (Separate multiple servers with spaces.)
  # Not used if NTPDATE_USE_NTP_CONF is yes.
  NTPSERVERS="ntp.ubuntu.com"

  # Additional options to pass to ntpdate
  NTPOPTIONS=""

  And the DHCP generated NTP server file is correct:

  ubuntu at sled204n0:/etc$ cat /var/lib/ntpdate/default.dhcp
  # NTP server entries received from DHCP server
  NTPSERVERS='172.31.22.1 172.31.23.1 172.31.20.104'

  The culprit seems to be in how ntpdate-debian is programmed. the logic
  ignores /var/lib/ntpdate/default.dhcp if /etc/default/ntpdate sets
  NTPDATE_USE_NTP_CONF=yes (the default).

  After examining the script further my recommendation would be for the
  /etc/dhcp/dhclient-exit-hooks.d/ntpdate to create the file
  /var/lib/ntp/ntp.conf.dhcp. By doing so ntpdate-debian will work
  transparently with /etc/defaults/ntpdate and NTP servers advertised by
  DHCPD.

  
  -------------------------------------------------------------------------
  (contents of /var/log/maas/* is 125MB in size, will post data from there if requested)

  # dpkg -l '*maas*'|cat
  Desired=Unknown/Install/Remove/Purge/Hold
  | Status=Not/Inst/Conf-files/Unpacked/halF-conf/Half-inst/trig-aWait/Trig-pend
  |/ Err?=(none)/Reinst-required (Status,Err: uppercase=bad)
  ||/ Name                               Version                                Architecture Description
  +++-==================================-======================================-============-==========================================================================
  ii  maas                               1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS Server
  ii  maas-cli                           1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS Client Tool
  ii  maas-cluster-controller            1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS Cluster Controller
  ii  maas-common                        1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS Server
  un  maas-dhcp                          <none>                                              (no description available)
  un  maas-dns                           <none>                                              (no description available)
  ii  maas-region-controller             1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS Server
  ii  python-django-maas                 1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS Server - (django files)
  ii  python-maas-client                 1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS API Client - (python files)
  ii  python-maas-provisioningserver     1.3+bzr1461+dfsg-0ubuntu2.2+tay.8      all          Ubuntu MAAS Server

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