I have this problem with Docker containers on one of my servers running OMV 5 on Debian 10.
Temporary failure resolving
About this setup. I have recently installed OMV 5 on two x86 and one ARM server. The problem appears just on one of server, while inside the host os dns seems to work fine, I can install and upgrade packages, in docker containers it simply does not work. I tried to followw several guides, nothing helped so far. Also restored the image and reinstalled docker several time. Also the servers have identical OS images just with a few configuration changes related to disks. I've tried this guide https://development.robinwinslow.uk/2016/06/23/fix-docker-networking-dns/ and this https://www.dedoimedo.com/computers/docker-container-no-network.html On all servers I get this
root@mars:~# docker run busybox nslookup google.com
Server: 192.168.1.1
Address: 192.168.1.1:53
Non-authoritative answer:
Name: google.com
Address: 172.217.20.174
*** Can't find google.com: No answer
On two servers it works (arm and x86):
root@venus:~# docker run -t -i ubuntu /bin/bash
root@9e4dce3d6ad9:/# apt update
Get:1 http://archive.ubuntu.com/ubuntu focal InRelease [265 kB]
Get:2 http://security.ubuntu.com/ubuntu focal-security InRelease [107 kB]
Get:3 http://archive.ubuntu.com/ubuntu focal-updates InRelease [107 kB]
Get:4 http://archive.ubuntu.com/ubuntu focal-backports InRelease [98.3 kB]
Get:5 http://security.ubuntu.com/ubuntu focal-security/universe amd64 Packages [8273 B]
Get:6 http://security.ubuntu.com/ubuntu focal-security/main amd64 Packages [60.9 kB]
Get:7 http://archive.ubuntu.com/ubuntu focal/multiverse amd64 Packages [177 kB]
Get:8 http://security.ubuntu.com/ubuntu focal-security/restricted amd64 Packages [4673 B]
Get:9 http://archive.ubuntu.com/ubuntu focal/universe amd64 Packages [11.3 MB]
Get:10 http://archive.ubuntu.com/ubuntu focal/main amd64 Packages [1275 kB]
Get:11 http://archive.ubuntu.com/ubuntu focal/restricted amd64 Packages [33.4 kB]
Get:12 http://archive.ubuntu.com/ubuntu focal-updates/universe amd64 Packages [31.6 kB]
Get:13 http://archive.ubuntu.com/ubuntu focal-updates/restricted amd64 Packages [4673 B]
Get:14 http://archive.ubuntu.com/ubuntu focal-updates/main amd64 Packages [104 kB]
Get:15 http://archive.ubuntu.com/ubuntu focal-backports/universe amd64 Packages [2903 B]
Fetched 13.6 MB in 10s (1389 kB/s)
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
root@9e4dce3d6ad9:/#
but on the 3rd(x86) I get this
root@mars:~# docker run -t -i ubuntu /bin/bash
root@173885bb1bfa:/# apt update
Err:1 http://archive.ubuntu.com/ubuntu focal InRelease
Temporary failure resolving 'archive.ubuntu.com'
Err:2 http://security.ubuntu.com/ubuntu focal-security InRelease
Temporary failure resolving 'security.ubuntu.com'
Err:3 http://archive.ubuntu.com/ubuntu focal-updates InRelease
Temporary failure resolving 'archive.ubuntu.com'
Err:4 http://archive.ubuntu.com/ubuntu focal-backports InRelease
Temporary failure resolving 'archive.ubuntu.com'
Reading package lists... Done
Building dependency tree
Reading state information... Done
All packages are up to date.
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal/InRelease Temporary failure resolving 'archive.ubuntu.com'
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal-updates/InRelease Temporary failure resolving 'archive.ubuntu.com'
W: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal-backports/InRelease Temporary failure resolving 'archive.ubuntu.com'
W: Failed to fetch http://security.ubuntu.com/ubuntu/dists/focal-security/InRelease Temporary failure resolving 'security.ubuntu.com'
W: Some index files failed to download. They have been ignored, or old ones used instead.
My router is running OpenWrt 19.07, I also reboot it amd delete the dhcp leases. Which resolved the problem that the installed could not auto configure networks. I also found and started a container with X and VNC. In browsers DNS works fines, but not in apt.
I also use henet tunnel brocker to get ipv6.
