"課題 9.3: CoreDNS を扱う" ２点質問

@hid-nakamura さん　ありがとうございます。

student@cp:~$ kubectl run test --restart=Never --image=alpine --rm -it -- nslookup www.kubernetes.io

If you don't see a command prompt, try pressing enter.
nslookup: write to '10.96.0.10': Connection refused
;; connection timed out; no servers could be reached

E0107 00:42:52.587726 4485 v2.go:105] EOF

これはnslookup出来てないものと思います

コントロールプレーンノードからはwww.kubernetes.ioは解決出来ています

student@cp:~$ dig www.kubernetes.io

; <<>> DiG 9.11.3-1ubuntu1.16-Ubuntu <<>> www.kubernetes.io
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 54421
;; flags: qr rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 65494
;; QUESTION SECTION:
;www.kubernetes.io. IN A

;; ANSWER SECTION:
www.kubernetes.io. 3600 IN CNAME kubernetes.io.
kubernetes.io. 3599 IN A 147.75.40.148

;; Query time: 121 msec
;; SERVER: 127.0.0.53#53(127.0.0.53)
;; WHEN: Fri Jan 07 02:30:22 UTC 2022
;; MSG SIZE rcvd: 76

coreDNSは稼働しています

student@cp:~$ kubectl get po -n kube-system

NAME READY STATUS RESTARTS AGE
calico-kube-controllers-5d995d45d6-zbrsc 1/1 Running 1 (15h ago) 21h
calico-node-4hjww 1/1 Running 2 (15h ago) 15d
calico-node-cv97s 1/1 Running 0 15d
calico-node-mnkdr 1/1 Running 2 (15h ago) 15d
coredns-78fcd69978-v2ksh 1/1 Running 1 (15h ago) 21h
coredns-78fcd69978-zgwpt 1/1 Running 1 (15h ago) 21h
etcd-cp 1/1 Running 2 (15h ago) 15d
kube-apiserver-cp 1/1 Running 41 (15h ago) 15d
kube-controller-manager-cp 1/1 Running 9 (15h ago) 15d
kube-proxy-9p2g6 1/1 Running 0 15d
kube-proxy-cg8jj 1/1 Running 2 (15h ago) 15d
kube-proxy-df54x 1/1 Running 2 (15h ago) 15d
kube-scheduler-cp 1/1 Running 9 (15h ago) 15d

coreDNSからコントロールプレーンノードでの解決が出来ていないように思います。なにか確認すべき設定等あれば教えてください。

補足：
バージョンを正確に記載します

student@cp:~$ kubectl version
Client Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.1", GitCommit:"632ed300f2c34f6d6d15ca4cef3d3c7073412212", GitTreeState:"clean", BuildDate:"2021-08-19T15:45:37Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.1", GitCommit:"632ed300f2c34f6d6d15ca4cef3d3c7073412212", GitTreeState:"clean", BuildDate:"2021-08-19T15:39:34Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}
student@cp:~$ kubeadm version
kubeadm version: &version.Info{Major:"1", Minor:"22", GitVersion:"v1.22.1", GitCommit:"632ed300f2c34f6d6d15ca4cef3d3c7073412212", GitTreeState:"clean", BuildDate:"2021-08-19T15:44:22Z", GoVersion:"go1.16.7", Compiler:"gc", Platform:"linux/amd64"}
student@cp:~$ cat /etc/os-release
NAME="Ubuntu"
VERSION="18.04.6 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.6 LTS"
VERSION_ID="18.04"
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"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic