coredns doesnt resolve names in kind v0.19.0 #6528

ep4sh · 2024-03-07T10:29:08Z

ep4sh
Mar 7, 2024

Hey folks, trying to run some services in kubernetes-kind and got timeout problems. I assume it's a DNS issue, since ingress controller cant find an upstream:

2024/03/06 15:39:14 [emerg] 78#78: host not found in upstream "nginx-ingress-controller-wallarm-tarantool:3313" in /etc/nginx/nginx.conf:254
nginx: [emerg] host not found in upstream "nginx-ingress-controller-wallarm-tarantool:3313" in /etc/nginx/nginx.conf:254

But this service exists in kubernetes.

I've tested the similar on kubernetes service and was surprised:

/ # cat /etc/resolv.conf 
search gitlab-public.svc.cluster.local svc.cluster.local cluster.local ru-central1.internal auto.internal
nameserver 10.102.128.2
options ndots:5
 
/ # dig kubernetes +short  # <<< OKAY, shouldn't be resolved

/ # dig kubernetes.default +short # <<<< NOT OKAY, should be resolved

/ # dig kubernetes.default.svc.cluster.local +short 
10.102.128.1 # <<<< OKAY, resolved as is

In configmap I see the default config:

apiVersion: v1
data:
  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
    }
kind: ConfigMap
metadata:
  creationTimestamp: "2024-03-07T09:48:07Z"
  name: coredns
  namespace: kube-system
  resourceVersion: "630"
  uid: 4fd4948f-ec8c-4eac-b433-780fd2e13cf7

I assume something like