Kubernetes : Metrics Server の設定2023/07/28

Metrics Server を設定して、Kubernetes クラスターの CPU/メモリーリソースのメトリクスを収集/監視します。

当例では以下のように 3 台のノードを使用して Kubernetes クラスターを構成しています。

-----------+---------------------------+--------------------------+------------
           |                           |                          |
       eth0|10.0.0.25              eth0|10.0.0.71             eth0|10.0.0.72
+----------+-----------+   +-----------+-----------+   +-----------+-----------+
|  [ ctrl.srv.world ]  |   |  [snode01.srv.world]  |   |  [snode02.srv.world]  |
|     Control Plane    |   |      Worker Node      |   |      Worker Node      |
+----------------------+   +-----------------------+   +-----------------------+

[1]	Control Plane ノードで Metrics Server を設定します。

root@ctrl:~#

git clone https://github.com/kubernetes-sigs/metrics-server

root@ctrl:~#

vi ./metrics-server/manifests/base/deployment.yaml

.....
.....
 containers:
      - name: metrics-server
        image: gcr.io/k8s-staging-metrics-server/metrics-server:master
        imagePullPolicy: IfNotPresent
        # 23行目 : 追記
        command:
        - /metrics-server
        - --kubelet-insecure-tls
        - --kubelet-preferred-address-types=InternalIP
        args:
          - --cert-dir=/tmp
          - --secure-port=10250
          - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
          - --kubelet-use-node-status-port
          - --metric-resolution=15s
.....
.....

root@ctrl:~#

kubectl apply -k ./metrics-server/manifests/base/

serviceaccount/metrics-server created
clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created
clusterrole.rbac.authorization.k8s.io/system:metrics-server created
rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created
clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created
clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created
service/metrics-server created
deployment.apps/metrics-server created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created

root@ctrl:~#

kubectl get pods -n kube-system

NAME                                      READY   STATUS    RESTARTS   AGE
calico-kube-controllers-56dd5794f-r7fvl   1/1     Running   0          5h57m
calico-node-89s9h                         1/1     Running   0          5h57m
calico-node-txrgc                         1/1     Running   0          69m
calico-node-x8qvh                         1/1     Running   0          70m
coredns-787d4945fb-6nn4p                  1/1     Running   0          6h2m
coredns-787d4945fb-qwxb5                  1/1     Running   0          6h2m
etcd-ctrl.srv.world                       1/1     Running   0          6h3m
kube-apiserver-ctrl.srv.world             1/1     Running   0          6h3m
kube-controller-manager-ctrl.srv.world    1/1     Running   0          6h3m
kube-proxy-fbfgj                          1/1     Running   0          6h2m
kube-proxy-gc6ff                          1/1     Running   0          69m
kube-proxy-zc2fn                          1/1     Running   0          70m
kube-scheduler-ctrl.srv.world             1/1     Running   0          6h3m
metrics-server-5698b55c7d-q48zb           1/1     Running   0          50s
# [metrics-server] pod が新規にデプロイされる

[2]	CPU やメモリーの使用状況は以下のように確認できます。

root@ctrl:~#

kubectl top node

NAME                CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
ctrl.srv.world      117m         1%     1731Mi          10%
snode01.srv.world   27m          0%     907Mi           11%
snode02.srv.world   37m          0%     1017Mi          6%

root@ctrl:~#

kubectl top pod

NAME                          CPU(cores)   MEMORY(bytes)
test-nginx-6b4d69f6f8-2jcb2   0m           7Mi
test-nginx-6b4d69f6f8-pwc5f   0m           7Mi
test-nginx-6b4d69f6f8-xjmd8   0m           4Mi