k8s的error: metrics not available yet问题处理

解决步骤

因项目要求，需在k8s集群中使用 kubectl top node命令，但是一直报error: metrics not available yet错误。为了更好的复现问题，我们将本次解决问题的步骤整理如下。

环境说明

k8s版本：v1.23.5
k8s部署方式：kubeadm

##版本说明，当前的k8s版本为v1.23.5
[root@XXXX ~]# kubectl get node
NAME                        STATUS   ROLES    AGE    VERSION
test-worker1   Ready       160d   v1.23.5
1
2
3
4

问题现象

#1 查看node出错
[root@XXXX ~]# kubectl top node
error: metrics not available yet

#2 查看pod没问题 
[root@XXXXX ~]# kubectl top pod
NAME               CPU(cores)   MEMORY(bytes)   
XXX-48jgq   16m          75Mi            
XXX-55g2z   12m          82Mi            
XXX-6tj6c   8m           143Mi 
1
2
3
4
5
6
7
8
9
10

初次排查

# 查看metrics.k8s.io的api情况
kubectl get --raw /apis/metrics.k8s.io/v1beta1 | python -m json.tool
{
    "apiVersion": "v1",
    "groupVersion": "metrics.k8s.io/v1beta1",
    "kind": "APIResourceList",
    "resources": [
        {
            "kind": "NodeMetrics",
            "name": "nodes",
            "namespaced": false,
            "singularName": "",
            "verbs": [
                "get",
                "list"
            ]
        },
        {
            "kind": "PodMetrics",
            "name": "pods",
            "namespaced": true,
            "singularName": "",
            "verbs": [
                "get",
                "list"
            ]
        }
    ]
}

#2 查看apiservices 服务
kubectl describe apiservices v1beta1.metrics.k8s.io
Status:
  Conditions:
    Last Transition Time:  2023-11-07T16:16:24Z
    Message:               all checks passed
    Reason:                Passed
    Status:                True
    Type:                  Available
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39

问题解决

部署metric-server，使用yaml方式进行部署，因为git下载不下来，我提前下载下来，然后换了阿里的镜像源，要注意metric-server和k8s版本的兼容性：

版本兼容性

根据图表，我们的k8s版本是1.23，因此我们使用metrics-server:v0.6.4

metric-server.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
    rbac.authorization.k8s.io/aggregate-to-admin: "true"
    rbac.authorization.k8s.io/aggregate-to-edit: "true"
    rbac.authorization.k8s.io/aggregate-to-view: "true"
  name: system:aggregated-metrics-reader
rules:
- apiGroups:
  - metrics.k8s.io
  resources:
  - pods
  - nodes
  verbs:
  - get
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
rules:
- apiGroups:
  - ""
  resources:
  - nodes/metrics
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - pods
  - nodes
  verbs:
  - get
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server-auth-reader
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: extension-apiserver-authentication-reader
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server:system:auth-delegator
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:auth-delegator
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:metrics-server
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  ports:
  - name: https
    port: 443
    protocol: TCP
    targetPort: https
  selector:
    k8s-app: metrics-server
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  strategy:
    rollingUpdate:
      maxUnavailable: 0
  template:
    metadata:
      labels:
        k8s-app: metrics-server
    spec:
      containers:
      - args:
        - --cert-dir=/tmp
        - --secure-port=4443
        - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
        - --kubelet-use-node-status-port
        - --metric-resolution=15s
        - --kubelet-insecure-tls 
        image: registry.cn-hangzhou.aliyuncs.com/rainux/metrics-server:v0.6.4
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /livez
            port: https
            scheme: HTTPS
          periodSeconds: 10
        name: metrics-server
        ports:
        - containerPort: 4443
          name: https
          protocol: TCP
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /readyz
            port: https
            scheme: HTTPS
          initialDelaySeconds: 20
          periodSeconds: 10
        resources:
          requests:
            cpu: 100m
            memory: 200Mi
        securityContext:
          allowPrivilegeEscalation: false
          readOnlyRootFilesystem: true
          runAsNonRoot: true
          runAsUser: 1000
        volumeMounts:
        - mountPath: /tmp
          name: tmp-dir
      nodeSelector:
        kubernetes.io/os: linux
      priorityClassName: system-cluster-critical
      serviceAccountName: metrics-server
      volumes:
      - emptyDir: {}
        name: tmp-dir
---
apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:
  labels:
    k8s-app: metrics-server
  name: v1beta1.metrics.k8s.io
spec:
  group: metrics.k8s.io
  groupPriorityMinimum: 100
  insecureSkipTLSVerify: true
  service:
    name: metrics-server
    namespace: kube-system
  version: v1beta1
  versionPriority: 100

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198

问题验证

#1 运行yaml文件
[root@k8s-master][~]
$kubectl create -f metrics-server.yaml

#2 问题验证
[root@XXXX][~]
$kubectl top node
NAME         CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master   194m         9%     1689Mi          35%       
     

[root@XXXX][~]
$kubectl top pod
NAME                                      CPU(cores)   MEMORY(bytes)   
cm-deploy-XXXX               0m           3Mi             
nfs-XXXXX   0m           13Mi 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16