Blank DNS entry won't delete

Users
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#1

We have found a DNS entry which causes a problem: It has no name value, so from MAAS the whole subdomain resolves to an unwanted IP, while from outside of MAAS it is already configured to resolve correctly. On the region controller:

maas:~$ head -12 /etc/bind/maas/zone.nimbus.pawsey.org.au 
; Zone file modified: 2022-10-27 19:11:26.026174.
$TTL 30
@   IN    SOA nimbus.pawsey.org.au. nobody.example.com. (
              0000986051 ; serial
              600 ; Refresh
              1800 ; Retry
              604800 ; Expire
              30 ; NXTTL
              )

@   30 IN NS pawsey.org.au.
 30 IN A 146.118.52.233

Notice the space starting the last line - by my reading that is why nimbus.pawsey.org.au resolves to that IP from MAAS. Externally it resolves correctly from upstream DNS to a different IP. At https:/ā€¦/MAAS/r/domain/1 (Name: nimbus.pawsey.org.au) I see what I think is the erroneous entry, screenshot attached of me trying to delete it.

Screenshot from 2022-10-27 20-50-59
Screenshot from 2022-10-27 20-50-591540Ɨ382 25.2 KB

maas SESSION dnsresources read | grep 146.118.52.233 finds the IP, but it is in an ā€˜ubuntuā€™ dnsresource record in another domain pawsey.org.au which also shows an entry in the web UI. That entry holds a lot of IPs, a few dozen named ā€˜ubuntuā€™. I think this is not relevant but am not sure.

$ maas SESSION dnsresource read 1899 | jq '.fqdn'
"ubuntu.pawsey.org.au"
$ maas SESSION dnsresource read 1899 | wc -l
117074
$ maas SESSION dnsresource read 1899 | jq '.ip_addresses | .[].ip' | wc -l
1511

I am left wondering if this snuck in quite some time ago (perhaps in an enlistment gone wrong?) in a previous version of MAAS, and in the current version that particular type of record canā€™t exist, and canā€™t be deleted. Do I need to dive into the database and delete something manually to fix this?

May I have some advice on this please?

#2

I guess I just need to start digging around the database to see what I can find. That can be a job for next week.

#3

sorry, @gregoryo2017 ā€“ we were on ā€œsprintā€ last week in the team; iā€™ll make sure someone gets their head wrapped around this soonest.

#4

Thanks - I tugged some other threads and am currently buried in automation, firewall and monitoring configs.

#5

Iā€™m still hoping for some attention on this. The problem still exists.

#6

Hi @gregoryo2017,
To make sure I understand the intended setup and issue, you have a domain (DNS zone with regards to BIND) pawsey.org.au, and then you have a delegated zone of nimbus.pawsey.org.au, are either of these the default MAAS domain? And then in one of these , you have an ubuntu.pawset.org.au A record, but then the erroneous empty label record with the same IP?

Additionally, what is that IP tied to? Is it a machine within MAAS? If so, what is the status (i.e is it deployed?)?

I would recommend opening a bug report with these questions addressed there along with what MAAS version you are using, if you can.

#7

Thanks for the message @cgrabowski and apologies for the delay - big migration under way here, nearly done, but itā€™s Christmas time now! I do want to get this sorted out, so will respond as soon as I can.

#9

In short, yes what you said is accurate. Iā€™m not sure about it being a ā€˜labelā€™ record, but in maas domain pawsey.org.au (httā€¦/MAAS/r/domain/0) there is a Resource record like so:

ubuntu	A	(default)	146.118.52.233

Any attempt to change or delete it yields sequence item 0: expected str instance, NoneType found. I canā€™t find any evidence of a machine with that IP address - nothing from arp or nmap either.

Shall I submit a bug report?

#10

A bump here in case someone can shed light on what to do to fix my problem.

#11

Hi @gregoryo2017, would you be able to provide the requested logs in the bug report? Itā€™s possible this is a validation error, and any related logs around this issue would help shed some light on whether thatā€™s the case.

#12

Thank you for the message! I donā€™t know why but I didnā€™t get a notification in the bug. Iā€™ll do it now.

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#13

@gregoryo2017, are you okay closing this one and tracking it via the bug? two open loops means twice the attention, but not necessarily twice the action :slight_smile:

#14

Iā€™m happy to go with your advice on that Bill.

1 Like
#15