12. 部署metrics监控组件

# 一、metrics-server(HPA使用)

1. 版本说明

github地址: https://github.com/kubernetes-sigs/metrics-server

2. Aggregator开启

这个是k8s在1.7的新特性，如果是1.16版本的可以不用添加，1.17以后要添加。这个参数的作用是Aggregation允许在不修改Kubernetes核心代码的同时扩展Kubernetes API。

查询是否开启：

master机器：
```
ps -ef |grep apiserver|grep 'enable-aggregator-routing=true'
```

开启方法：要在master机器上执行

需要在/etc/kubernetes/manifests/kube-apiserver.yaml文件内的`- kube-apiserver`后追加开启参数:
```
--enable-aggregator-routing=true //追加该参数
```

配置命令,执行后apiserver会自动重启
```
sed -i 's#- kube-apiserver#- kube-apiserver\n    - --enable-aggregator-routing=true#g' \
/etc/kubernetes/manifests/kube-apiserver.yaml
```

修改k8s-master的pod配置，让其从默认的127.0.0.1改为监听0.0.0.0
避免prometheus部署后无法访问地址而告警
```
sed -i 's#- \--bind-address=.*#- \--bind-address=0.0.0.0#g' \
/etc/kubernetes/manifests/kube-scheduler.yaml

sed -i 's#- \--bind-address=.*#- \--bind-address=0.0.0.0#g' \
/etc/kubernetes/manifests/kube-controller-manager.yaml
```

3. 部署

下载yaml文件
```
wget https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml
```

修改配置
```
# vim components.yaml
apiVersion: apps/v1
kind: Deployment
spec:
  template:
    metadata:
      labels:
        k8s-app: metrics-server
    spec:
      containers:
      - args:
        - --kubelet-insecure-tls # 跳过 TLS 认证，否则会出现 x509 的认证问题
        - --kubelet-preferred-address-types=InternalIP # 使用 Node IP 进行通信。
	    image: k8s.localvps.top/metrics-server/metrics-server:v0.7.1 # 使用加速地址
```

创建资源
```
kubectl apply -f components.yaml
```

检验相应的API群组metrics.k8s.io是否出现在Kubernetes集群的API群组列表中
```
kubectl api-versions | grep metrics
```

确认相关的Pod对象运行正常
```
kubectl get pods -n kube-system -l k8s-app=metrics-server
```

使用kubectl top node查看结果
```
[root@tiaoban ~]# kubectl top node
NAME         CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master   422m         10%    1471Mi          40%       
k8s-work1    268m         6%     1197Mi          33%       
k8s-work2    239m         5%     1286Mi          35%       
k8s-work3    320m         8%     1091Mi          30% 
```

# 二、kube-state-metrics部署(prometheus采集数据使用)

版本依赖
```
kube-state-metrics	Kubernetes 1.18	Kubernetes 1.19	Kubernetes 1.20	Kubernetes 1.21	Kubernetes 1.22
v1.9.8	-	-	-	-	-
v2.0.0	-/✓	✓	✓	-/✓	-/✓
v2.1.1	-/✓	✓	✓	✓	-/✓
v2.2.0	-/✓	✓	✓	✓	✓
master	-/✓	✓	✓	✓	✓
```

克隆项目至本地
```
# git clone https://github.com/kubernetes/kube-state-metrics.git
# cd kube-state-metrics/examples/standard/
```

修改service，允许prometheus自动发现
```
# vim service.yaml
apiVersion: v1
kind: Service
metadata:
  labels:
    app.kubernetes.io/name: kube-state-metrics
    app.kubernetes.io/version: 2.2.0
  name: kube-state-metrics
  namespace: kube-system
  annotations:  
    prometheus.io/scrape: "true"       ##添加此参数，允许prometheus自动发现
```

创建资源
```
kubectl apply -f .
[root@tiaoban standard]# kubectl get pod -n kube-system -l app.kubernetes.io/name=kube-state-metrics
NAME                                 READY   STATUS    RESTARTS   AGE
kube-state-metrics-bb59558c8-cx9pz   1/1     Running   0          1m
```

使用kubectl top node查看结果

```
[root@tiaoban  ~]# kubectl top node 
NAME         CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%
k8s-master   422m         10%    1471Mi          40%
k8s-work1    268m         6%     1197Mi          33%
k8s-work2    239m         5%     1286Mi          35%
k8s-work3    320m         8%     1091Mi          30%
```