[Maas-devel] juju's private-address, DNS, MAAS and postgresql

[Andreas Hasenack]

This may be more appropriate for the MAAS mailing list after all. The
reason I originally sent it to juju was that line added to /etc/hosts,
which I think was done by juju (see at the end of the email)


Sorry for the confusing subject line.

This is the issue:
2013-11-07 13:47:02 UTC FATAL:  no pg_hba.conf entry for host "10.0.5.100",
user "landscape", database "landscape-standalone-main", SSL off
2013-11-07 13:47:02 UTC DETAIL:  Client IP address resolved to
"10-0-5-100.maaslocal", forward lookup not checked.

My landscape unit (kmkxr.maaslocal) cannot talk to postgresql.

pg_hba.conf:
host all all kmkxr.maaslocal md5

connecting machine is 10.0.5.100:
# host 10.0.5.100
 100.5.0.10.in-addr.arpa domain name pointer 10-0-5-100.maaslocal.

# host kmkxr.maaslocal
kmkxr.maaslocal is an alias for 10-0-5-100.maaslocal.
10-0-5-100.maaslocal has address 10.0.5.100

Postgresql does a reverse lookup on the connecting IP, which gives it the
name "10-0-5-100.maaslocal". That doesn't match the entry in pg_hba.conf
(kmkxr.maaslocal), and the connection is rejected.

The "kmkxr.maaslocal" string came from the juju relation "private-address"
key:

postgresql/0:db-admin-relation-changed % relation-get
private-address: kmkxr.maaslocal

On that kmkxr machine /etc/hosts has this entry:
# Added by cloud-init on Thu, 07 Nov 2013 13:11:18 +0000
127.0.1.1 kmkxr.maaslocal kmkxr

And:
root at kmkxr:~# hostname -f
kmkxr.maaslocal

I'm guessing that's why private-address was set to kmkxr.maaslocal
(although "address" implies an IP to me, not a fqdn).

If I remove that entry from /etc/hosts:
root at kmkxr:~# hostname -f
10-0-5-100.maaslocal

As I understand it, maas pre-generates all possible A and PTR records for
the network it was given, and adds CNAMEs as machines get provisioned. In
this case, kmkxr.maaslocal is a CNAME, but at the same time it was added to
/etc/hosts.

So, I don't know where the bug is. I'm tempted to say we shouldn't add that
/etc/hosts entry since everything is in DNS handled by maas.

In any case, the postgresql charm can't get the unit's connecting IP from
the relation data unless it's explicitly set.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.ubuntu.com/archives/maas-devel/attachments/20131108/197e5521/attachment.html>