MicroK8s : ダッシュボードを有効にする2020/08/03

MicroK8s クラスターでダッシュボードを有効にする場合は以下のように設定します。

[1]	プライマリーノードで、ダッシュボードアドオンを有効にします。

root@dlp:~#

microk8s enable dashboard dns

Enabling Kubernetes Dashboard
Enabling Metrics-Server
clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created
clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created
rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created
serviceaccount/metrics-server created
deployment.apps/metrics-server created
service/metrics-server created
clusterrole.rbac.authorization.k8s.io/system:metrics-server created
clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created
clusterrolebinding.rbac.authorization.k8s.io/microk8s-admin created
Adding argument --authentication-token-webhook to nodes.
Applying to node node01.srv.world.
Metrics-Server is enabled
Applying manifest
serviceaccount/kubernetes-dashboard created
service/kubernetes-dashboard created
secret/kubernetes-dashboard-certs created
secret/kubernetes-dashboard-csrf created
secret/kubernetes-dashboard-key-holder created
configmap/kubernetes-dashboard-settings created
role.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrole.rbac.authorization.k8s.io/kubernetes-dashboard created
rolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard created
deployment.apps/kubernetes-dashboard created
service/dashboard-metrics-scraper created
deployment.apps/dashboard-metrics-scraper created

If RBAC is not enabled access the dashboard using the default token retrieved with:

token=$(microk8s kubectl -n kube-system get secret | grep default-token | cut -d " " -f1)
microk8s kubectl -n kube-system describe secret $token

In an RBAC enabled setup (microk8s enable RBAC) you need to create a user with restricted
permissions as shown in:
https://github.com/kubernetes/dashboard/blob/master/docs/user/access-control/creating-sample-user.md

Enabling DNS
Applying manifest
serviceaccount/coredns created
configmap/coredns created
deployment.apps/coredns created
service/kube-dns created
clusterrole.rbac.authorization.k8s.io/coredns created
clusterrolebinding.rbac.authorization.k8s.io/coredns created
Restarting kubelet
Adding argument --cluster-domain to nodes.
Applying to node node01.srv.world.
Adding argument --cluster-dns to nodes.
Applying to node node01.srv.world.
Restarting nodes.
Applying to node node01.srv.world.
DNS is enabled

root@dlp:~#

microk8s kubectl get services -n kube-system

NAME                        TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)                  AGE
dashboard-metrics-scraper   ClusterIP   10.152.183.56   <none>        8000/TCP                 119s
kube-dns                    ClusterIP   10.152.183.10   <none>        53/UDP,53/TCP,9153/TCP   119s
kubernetes-dashboard        ClusterIP   10.152.183.7    <none>        443/TCP                  119s
metrics-server              ClusterIP   10.152.183.50   <none>        443/TCP                  2m

# セキュリティトークン確認

# [token:] 行の二列目が該当

root@dlp:~#

microk8s kubectl -n kube-system describe secret $(microk8s kubectl -n kube-system get secret | grep default-token | awk '{print $1}')

Name:         default-token-n9m8r
Namespace:    kube-system
Labels:       <none>
Annotations:  kubernetes.io/service-account.name: default
              kubernetes.io/service-account.uid: 823d56bf-ba7a-46c2-915b-37e9bbdf3331

Type:  kubernetes.io/service-account-token

Data
====
namespace:  11 bytes
token:      eyJhbGciOiJSUzI1NiIsImtpZCI6ImRlWTdDUnpYaVd5N2hxVkczblpqNldyMzFzNWptQ3FjeW.....

# 外部からもアクセスできるようにポートフォワードする

root@dlp:~#

microk8s kubectl port-forward -n kube-system service/kubernetes-dashboard --address 0.0.0.0 10443:443

Forwarding from 0.0.0.0:10443 -> 8443

[2]	ローカルネットワーク内の任意のクライアントコンピューターで Web ブラウザーを起動し、[https://(MicroK8s プライマリーノードのホスト名または IP アドレス):10443/] にアクセスします。以下のような画面が表示されたら、[1] で確認したセキュリティトークンをコピー & ペーストして [Sing In] ボタンをクリックします。なお、下例の画面は英語表示となっていますが、日本語 OS でアクセスすれば日本語で表示されます。

[3]	認証が成功すると MicroK8s クラスターのダッシュボードが表示されます。