Listen tcp :53: bind: permission denied ERROR!!

Tej-Singh-Rana commented 1 month ago

What happened:

kubectl get po -A
NAMESPACE      NAME                                   READY   STATUS             RESTARTS      AGE
kube-flannel   kube-flannel-ds-962vp                  1/1     Running            0             15m
kube-flannel   kube-flannel-ds-qs6xr                  1/1     Running            0             15m
kube-system    coredns-7db6d8ff4d-6w776               0/1     CrashLoopBackOff   1 (10s ago)   12s
kube-system    coredns-7db6d8ff4d-99tng               0/1     CrashLoopBackOff   1 (9s ago)    12s
kube-system    etcd-controlplane                      1/1     Running            0             12m
kube-system    kube-apiserver-controlplane            1/1     Running            0             12m
kube-system    kube-controller-manager-controlplane   1/1     Running            0             12m
kube-system    kube-proxy-hbt5b                       1/1     Running            0             12m
kube-system    kube-proxy-x96js                       1/1     Running            0             11m
kube-system    kube-scheduler-controlplane            1/1     Running            0             12m

I was setting up the single-node k8s cluster (1 controlplane and 1 worker node). After going through all the installation process from the official k8s site -> at last, after deploying the network plugin on the k8s cluster. CoreDNS pods went into a Crashloopbackoff state. I did check for the container logs and found the following error message:

 listen tcp :53: bind: permission denied

What you expected to happen:

Both coreDNS pods should be in the running state, after deploying the network plugin.

How to reproduce it (as minimally and precisely as possible):

Simply follow the steps from the official k8s site.

Anything else we need to know?: I did some tests, and I used 1024 instead of 53 port, and it started to work.

kubectl logs -n kube-system coredns-7db6d8ff4d-wchnq 
.:1024
[INFO] plugin/reload: Running configuration SHA512 = e20da72760199c1bc59098f3ae16621ae48df8f7756e50bd0dfa5553ccb7be57af61562fff46a43fdcce51ac086b26aa19929386004908ad3afe3aea9b06316a
CoreDNS-1.11.1
linux/amd64, go1.20.7, ae2bbc2

Environment:

the version of CoreDNS: registry.k8s.io/coredns/coredns:v1.11.1

Corefile: The below content is from the coredns configMap.

Corefile: |
.:53 {
    errors
    health {
       lameduck 5s
    }
    ready
    kubernetes cluster.local in-addr.arpa ip6.arpa {
       pods insecure
       fallthrough in-addr.arpa ip6.arpa
       ttl 30
    }
    prometheus :9153
    forward . /etc/resolv.conf {
       max_concurrent 1000
    }
    cache 30
    loop
    reload
    loadbalance
}

logs, if applicable:
```
listen tcp :53: bind: permission denied
```

OS (e.g: cat /etc/os-release):

PRETTY_NAME="Ubuntu 22.04.4 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.4 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy

osho-20 commented 3 days ago

would like to work on this

mariuskimmina commented 3 days ago

I don't think there is anything to be done here on the CoreDNS site, it's a problem with the setup. The ports 1-1023 are privileged ports and require sudo permissions, which seem to be missing here. I didn't go through the installation guide, it could be that there is some problem in that - I am pretty sure that this is not a bug in CoreDNS tho.

coredns / coredns

Listen tcp :53: bind: permission denied ERROR!! #6716