DNS-Resolver inside Libreoffice Docker Container Installation

[digitalshow]

The package bbb-libreoffice-docker tries to build a docker container and add some debian packages. For me, this failed during the installation of the package:

Package locales-all is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'locales-all' has no installation candidate
E: Unable to locate package libxt6
E: Unable to locate package libxrender1
The command '/bin/sh -c apt -y install locales-all fontconfig libxt6 libxrender1' returned a non-zero code: 100
dpkg: error processing package bbb-libreoffice-docker (--configure):
 installed bbb-libreoffice-docker package post-installation script subprocess returned error exit status 100

I found out this was a name resolution issue, apt update failed to fetch the package lists (I still wonder why the Dockerfile didn't fail at that point already). The recommended Ubuntu Server 18.04 uses systemd-resolved, which presents a local caching resolver and registers this at /etc/resolv.conf. Docker seems to notice that that one is not reachable inside containers so it falls back to Google's DNS servers and registers them at the container's /etc/resolv.conf. Inside our network, these are not reachable. My solution was to use our local DNS resolver directly inside the host's /etc/resolv.conf, which will be used by docker:

rm /etc/resolv.conf
echo "nameserver 10.11.12.13" > /etc/resolv.conf

Do we want to add that to the Documentation? If not, this issue might still help people hitting the same problem.

[ffdixon]

Added to docs -- thanks.

https://docs.bigbluebutton.org/2.3/install.html#package-locales-all-is-not-available

[devpoorya]

Greetings,
I still can't manage to get this working. What DNS server should I use inside my /etc/resolv.conf?

[arnounesco]

this can no longer be correct as the package bbb-libreoffice does not exis, there is only a package bbb-libreoffice-docker

trying this solution did not solve the problem on Ubuntu 18.
if you do

systemd-resolve --status

after doing

echo "nameserver 8.8.8.8" > /etc/resolv.conf

you will not see the new nameserver there, anyhow rebooting the machine will overwrite you settings again

[digitalshow]

this can no longer be correct as the package bbb-libreoffice does not exis, there is only a package bbb-libreoffice-docker

I'm sorry, the correct package name is and was bbb-libreoffice-docker as seen in the error message, I changed it above.

you will not see the new nameserver there, anyhow rebooting the machine will overwrite you settings again

That happens because in a normal systemd-resolved setup /etc/resolv.conf is a symlink to a file managed by systemd-resolved. That's why I started with rm /etc/resolv.conf removing the symlink. I just noticed that that step was not taken to the documentation. I'm opening a pull request for that.

[devpoorya]

I still don't understand what DNS should I use inside my resolv.conf file because 10.11.12.13 clearly doesn't work and I'm still unable to install a BigBlueButton 2.3 instance.

[aminvakil]

10.11.12.13 is not an IP you can reach, see https://en.wikipedia.org/wiki/Private_network#Private_IPv4_addresses.

Just use 8.8.8.8, 1.1.1.1 or any other public dns server you like.