XOA Kubernetes Recipe FYI CoreDNS not starting (unreachable backend: read udp )

naeemarsalan

Hey Guys,

I recently used the XOA Recipe to create Kuberentes Cluster but by default it uses debian as os image. Which causes the internal Kube Proxy to fail to resolve DNS internally.

2018/11/12 07:40:00 [ERROR] 2 AAAA: unreachable backend: read udp 192.168.18.1:36161->10.0.2.3:53: i/o timeout

Apply the Following fix on all Master/Nodes

sudo update-alternatives --set iptables /usr/sbin/iptables-legacy
sudo update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy

Restart Master/Node Machines and then CoreDNS pods will start to work.

Solution Provided By This Blog Post:
https://www.jeffgeerling.com/blog/2019/debugging-networking-issues-multi-node-kubernetes-on-virtualbox

BenjiReis

@naeemarsalan Good catch, It will be added to the cloudinit script creating the master and the nodes.

This will save one reboot to everyone.