'How do I execute kubelet --resolve-conf?:

I am running into an issue where coredns doesn't seem to be working on my ubuntu instance, I get allot of the following errors from the logs:

2020-07-16T05:28:36.648Z [INFO] 172.17.0.8:60594 - 29368 "AAAA IN redis-master.cluster.local. udp 44 false 512" NXDOMAIN qr,rd 137 0.000053955s
2020-07-16T05:28:36.650Z [INFO] 172.17.0.8:43585 - 56935 "AAAA IN redis-master. udp 30 false 512" NXDOMAIN qr,rd,ra 30 0.001305981s
2020-07-16T05:28:36.650Z [INFO] 172.17.0.8:43585 - 55951 "A IN redis-master. udp 30 false 512" NXDOMAIN qr,rd,ra 30 0.001790145s
2020-07-16T05:28:36.803Z [INFO] 172.17.0.11:60313 - 14198 "A IN redis-master.cluster.local. udp 44 false 512" NXDOMAIN qr,rd 137 0.000083909s
2020-07-16T05:28:36.803Z [INFO] 172.17.0.11:60313 - 14670 "AAAA IN redis-master.cluster.local. udp 44 false 512" NXDOMAIN qr,rd 137 0.000078636s
2020-07-16T05:28:36.808Z [INFO] 172.17.0.11:42385 - 5737 "A IN redis-master.svc.cluster.local. udp 48 false 512" NXDOMAIN qr,rd 141 0.000095061s
2020-07-16T05:28:36.808Z [INFO] 172.17.0.11:42385 - 6139 "AAAA IN redis-master.svc.cluster.local. udp 48 false 512" NXDOMAIN qr,rd 141 0.000088591s
2020-07-16T05:28:36.809Z [INFO] 172.17.0.11:47547 - 18338 "A IN redis-master.cluster.local. udp 44 false 512" NXDOMAIN qr,rd 137 0.000077331s

I'm hoping that the following paragraph from the docs found here is the solution:

Some Linux distributions (e.g. Ubuntu) use a local DNS resolver by default (systemd-resolved). Systemd-resolved moves and replaces /etc/resolv.conf with a stub file that can cause a fatal forwarding loop when resolving names in upstream servers. This can be fixed manually by using kubelet's --resolv-conf flag to point to the correct resolv.conf (With systemd-resolved, this is /run/systemd/resolve/resolv.conf). kubeadm automatically detects systemd-resolved, and adjusts the kubelet flags accordingly.

However, I lack an understanding of how to execute the call to the kubelet. I could use an explanation or code example of how it is supposed to be done.

I am not sure if it is relevant but I am using minikube to test my cluster.

Thanks in advance for any help, Cheers!

kubernetesminikubecoredns


Solution 1:[1]

Sounds like a conflict with systemd-resolved and coredns in your minikube. You can try disabling systemd-resolved since you didn't create your cluster using kubeadm:

  • Disable systemd-resolved ??

    sudo systemctl disable systemd-resolved
sudo systemctl stop systemd-resolved

  • Put this line in the [main] section of your /etc/NetworkManager/NetworkManager.conf ?:

    dns=default

  • Delete the symlink /etc/resolv.conf ??

    sudo rm /etc/resolv.conf

  • Restart NetworkManager ????????????????

    sudo systemctl restart NetworkManager

Solution 2:[2]

I experienced this issue today, this is what I found - am still validating this answer.

https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/

Create the following file for every host running kubelet.

/etc/systemd/system/docker.service.d/10-docker-opts.conf

[Service]
MountFlags=shared
Environment="DOCKER_OPTS=--resolv-conf=/run/systemd/resolve/resolv.conf"

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution Source
Solution 1
Solution 2 Tomp736

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