docker version tag > 2021.11: ERROR: ServerIPv6 Environment variable (X:X:X:X:X:X:X:X) doesn't appear to be a valid IPv6 address

[martialt]

Versions

• Pi-hole: ??
• AdminLTE: ??
• FTL: v5.12
• Docker tag: 2021.12

Platform

• OS and version: Ubuntu 20.04.3 LTS

• Platform: Docker

Expected behavior

Start Pi-hole container with IPv6 support.

Actual behavior / bug

RTNETLINK answers: Network is unreachable
ERROR: ServerIPv6 Environment variable (X:X:X:X:X:X:X:X) doesn't appear to be a valid IPv6 address
  TIP: If your server is not IPv6 enabled just remove '-e ServerIPv6' from your docker container

Steps to reproduce

Steps to reproduce the behavior:

1. Start container with image version > 2021.11 and env var ServerIPv6

[dschaper]

Without seeing the value of the envar entry or the docker-compose file, it's hard to troubleshoot.

[martialt]

Hi Dan,

I cannot show you my public IPv6 address but she is normal, I just upgrade the version of the docker image from v2021.11 to v2021.12, an error is raising and the container did not start anymore.
I attached the docker inspect output and the docker compose file.
My IPv4, IPv6 and virtual hostname are masked.

Regards,

docker-compose.yml.log
pihole_container_inspect.json.log

[martialt]

Also the docker container logs output.

[s6-init] making user provided files available at /var/run/s6/etc...exited 0.
[s6-init] ensuring user provided files have correct perms...exited 0.
[fix-attrs.d] applying ownership & permissions fixes...
[fix-attrs.d] 01-resolver-resolv: applying... 
[fix-attrs.d] 01-resolver-resolv: exited 0.
[fix-attrs.d] done.
[cont-init.d] executing container initialization scripts...
[cont-init.d] 20-start.sh: executing... 
 ::: Starting docker specific checks & setup for docker pihole/pihole
Assigning random password: aYpZtJlq
RTNETLINK answers: Network is unreachable
ERROR: ServerIPv6 Environment variable (mypublicipv6masked) doesn't appear to be a valid IPv6 address
  TIP: If your server is not IPv6 enabled just remove '-e ServerIPv6' from your docker container
[cont-init.d] 20-start.sh: exited 1.
[cont-finish.d] executing container finish scripts...
[cont-finish.d] done.
[s6-finish] waiting for services.
[s6-finish] sending all processes the TERM signal.
[s6-finish] sending all processes the KILL signal and exiting.

[PromoFaux]

Here is where the checks are failing (line 65) :

docker-pi-hole/bash_functions.sh

Lines 65 to 69 in 9a9ee41

	if [[ "$(nc -6 -w1 -z "$ServerIPv6" 53 2>&1)" != "" ]] && ! ip route get "$ServerIPv6" > /dev/null ; then
	echo "ERROR: ServerIPv6 Environment variable ($ServerIPv6) doesn't appear to be a valid IPv6 address"
	echo " TIP: If your server is not IPv6 enabled just remove '-e ServerIPv6' from your docker container"
	exit 1
	fi

This code has not been touched for a couple of years, so nothing should have changed here between the two tagged versions.

I can maybe suggest running those two checks manually on the CLI, and from within the container to see if that gives you any clues, but it looks as though maybe it's a networking issue - as opposed to an issue with the IP string you are passing in

[martialt]

Hi,

I did some tests and I think the nc command is not included anymore inside the base image.
The base image has changed between 2021.11 and 2021.12.

docker-pi-hole/Dockerfile

Lines 1 to 3 in b0a5a0f

	ARG PIHOLE_BASE
	FROM "${PIHOLE_BASE:-ghcr.io/pi-hole/docker-pi-hole-base:buster-slim}"

[PromoFaux]

Oh, yes of course - egg on my face! It was removed from the core Pi-hole install script (although it will be re-added for the next release), and so it does not get installed when it runs in the docker build script.

I'll add it to the base image and tag a new container asap

[martialt]

Happens !
Thank you and happy new year...

[X-Xadro]

With me what made it work was that my ENV was using 'ServerIP' and 'ServerIPv6' and i read in the README.md that they were going to be deprecated so i changed them into 'FTLCONF_REPLY_ADDR4' and 'FTLCONF_REPLY_ADDR6'

But right before that i also did this: https://docs.docker.com/config/daemon/ipv6/ 'Enable IPv6 support'

Also want to point i'm a total newb so i only half understood what i did. But it did work so i'm happy.

[PromoFaux]

This should be fixed in the latest image.

ServerIP and ServerIPv6 will be deprecated at some point, just need to face the task of going through and untangling them from the rest of the image... (per #956)

[arctic-alpaca]

Using ServerIP and ServerIPv6 with the latest image still leads to the error described in #961 (comment).

Replacing ServerIP and ServerIPv6 with FTLCONF_REPLY_ADDR4 and FTLCONF_REPLY_ADDR6 allowed the container to start as normal.

[martialt]

I replace them and works with image tag 2022.01.1.
Thanks