DNS resolution is not available (Ubuntu 18.04.1)

ubuntu

#1

Expected Behaviour:

After installing on a fresh Ubuntu 18.04.1 LXC container, which is the only uncommon aspect of this install, the installer should report DNS resolution is available.

Actual Behaviour:

The installer reports that DNS resolution is not available. Calling ‘pihole status’ also reports the DNS resolution is not available.

Debug Token:

zuilm1vtrl

I have another Pi-hole install running under a container on Ubuntu 16.04 LTS. When I updated it this morning I got the same behaviour as when installing it under 18.04.


#2

These related threads may be of assistance:


#4

The third link (Installed Pi-hole but No DNS Resolution (Ubuntu 18.04.1)) sort of helped.

Here is what I get:

root@pihole2:~# service pihole-FTL status
● pihole-FTL.service - LSB: pihole-FTL daemon
Loaded: loaded (/etc/init.d/pihole-FTL; generated)
Active: active (exited) since Mon 2018-10-08 21:51:59 UTC; 4s ago
Docs: man:systemd-sysv-generator(8)
Process: 8526 ExecStop=/etc/init.d/pihole-FTL stop (code=exited, status=0/SUCCESS)
Process: 8530 ExecStart=/etc/init.d/pihole-FTL start (code=exited, status=0/SUCCESS)

Oct 08 21:51:59 pihole2 pihole-FTL[8530]: Not running
Oct 08 21:51:59 pihole2 pihole-FTL[8530]: chown: cannot access ‘/etc/pihole/dhcp.leases’: No such file or directory
Oct 08 21:51:59 pihole2 pihole-FTL[8530]: Failed to set capabilities on file `/usr/bin/pihole-FTL’ (Operation not permitted)
Oct 08 21:51:59 pihole2 pihole-FTL[8530]: The value of the capability argument is not permitted for a file. Or the file is not a regular (non-symlink) file
Oct 08 21:51:59 pihole2 su[8553]: Successful su for pihole by root
Oct 08 21:51:59 pihole2 su[8553]: + ??? root:pihole
Oct 08 21:51:59 pihole2 su[8553]: pam_unix(su:session): session opened for user pihole by (uid=0)
Oct 08 21:51:59 pihole2 pihole-FTL[8530]: dnsmasq: failed to create listening socket for 192.168.1.3: Permission denied
Oct 08 21:51:59 pihole2 su[8553]: pam_unix(su:session): session closed for user pihole
Oct 08 21:51:59 pihole2 systemd[1]: Started LSB: pihole-FTL daemon.

It looks like restarting pihole-FTL is having problems setting capabilities on /usr/bin/pihole-FTL.


#5

#6

Ok. That worked.

After changing the line in /etc/init.d/pihole-FTL from:

su -s /bin/sh -c "/usr/bin/pihole-FTL" "$FTLUSER"

to:

/usr/bin/pihole-FTL

then doing a:

sudo systemctl daemon-reload

and finally a:

sudo service pihole-FTL restart

the result of a pihole status becomes:

[✓] DNS service is running
[✓] Pi-hole blocking is Enabled

So that’s something.

But is Ubuntu under LXC, or Ubuntu 16.04 to 18.04 considered a supported target? If it is, it is a piece of cake for me to test any possible solutions.


#7

As of now, Ubuntu 16.04 and 16.10 are the officially supported versions. There are users running on 18.04, many with problems similar to what you are seeing.

https://docs.pi-hole.net/main/prerequesites/

Is your Pi-Hole working properly now? If you like, upload a debug log and we’ll look at it.


#8

I had the same symptoms under Ubuntu 16.04, also under LXC. I just deleted the container, so I can’t be sure that the fix would have worked with it too.

Yes, my Pi-Hole container is working fine. The issue can be closed, but I’m happy to help with the larger issue if I can.