DNS-Resolver inside Libreoffice Docker Container Installation #385
Description
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.