简单介绍

 Prometheus 是一款基于时序数据库的开源监控告警系统，非常适合Kubernetes集群的监控。Prometheus的基本原理是通过HTTP协议周期性抓取被监控组件的状态，任意组件只要提供对应的HTTP接口就可以接入监控。不需要任何SDK或者其他的集成过程。这样做非常适合做虚拟化环境监控系统，比如VM、Docker、Kubernetes等。输出被监控组件信息的HTTP接口被叫做exporter 。目前互联网公司常用的组件大部分都有exporter可以直接使用，比如Varnish、Haproxy、Nginx、MySQL、Linux系统信息(包括磁盘、内存、CPU、网络等等)。

安装K8s

这次我们安装的版本是K8s是20.10.7 ，docker是20.10.5。 这里分配三台机器,分别是master(10.10.162.35），worker1(10.10.162.36）,worker2(10.10.162.37）

关闭防火墙,selinux

setenforce 0
systemctl stop firewalld.service ; systemctl disable firewalld.service

1.安装docker

三台机器分别安装

yum -y install -y yum-utils device-mapper-persistent-data lvm2

yum-config-manager \
    --add-repo \
    https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

安装docker    
yum install docker-ce-20.10.5 docker-ce-cli-20.10.5 docker-ce-rootless-extras-20.10.5 -y

//启动docker
systemctl start docker

修改docker的镜像源为国内镜像,修改/etc/docker/daemon.json

{
    "registry-mirrors": ["https://mirror.ccs.tencentyun.com"]
}

修改完成后，重启docker

systemctl daemon-reload
systemctl restart docker.service

2.安装K8S

配置阿里云kubernetes源

cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=https://mirrors.aliyun.com/kubernetes/yum/repos/kubernetes-el7-x86_64/
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://mirrors.aliyun.com/kubernetes/yum/doc/yum-key.gpg https://mirrors.aliyun.com/kubernetes/yum/doc/rpm-package-key.gpg
EOF

yum clean all
yum -y makecache

新增br_netfilter模块，要求iptables对bridge的数据进行处理

modprobe br_netfilter
echo "1" > /proc/sys/net/bridge/bridge-nf-call-iptables
echo "1" >  /proc/sys/net/ipv4/ip_forward 

cat <<EOF >  /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
EOF

sysctl -p /etc/sysctl.d/k8s.conf

禁用swap
swapoff -a
sed -i.bak '/swap/s/^/#/' /etc/fstab

安装20版本k8s,三台机器都开始安装
yum install -y kubelet-1.20.9 kubeadm-1.20.9 kubectl-1.20.9
mkdir -p  /etc/cni/net.d

分别设置三台主机的hostname

master主机设置
hostnamectl set-hostname master

worker主机设置
hostnamectl set-hostname worker1

worker2主机设置
hostnamectl set-hostname worker2

初始化Master主机

#service-cidr设置的service的主机ip范围，pod-network-cidr设置的是pod的ip范围，为什么要用10.244这个网段呢，因为10.244.0.0/16 这个网段这是flannel指定的网段.

kubeadm init --kubernetes-version=1.20.9 --apiserver-advertise-address=10.10.162.35 --image-repository registry.aliyuncs.com/google_containers --service-cidr=10.1.0.0/16 --pod-network-cidr=10.244.0.0/16

运行完成后会master主机会显示如下内容，代表主节点初始化成功。

这里有一个语句特别要记住，这是工作节点主机加入master的关键执行命令。

kubeadm join 10.10.162.35:6443 --token cj86ui.lo3l9o9f0d6u8p0q \
    --discovery-token-ca-cert-hash sha256:0b50df18d8716e06350e0e5698ced0a1ea14a36d7a6ddb04143b35e0471f8f45

接下来的worker1,worker2分别运行上面的语句加入master主节点集群
worker1加入

worker2加入

master主节点增加kubectl密钥访问

mkdir -p $HOME/.kube
/usr/bin/cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
chown $(id -u):$(id -g) $HOME/.kube/config

echo "export KUBECONFIG=/etc/kubernetes/admin.conf" >> ~/.bash_profile 

然后我们运行系统命令，看整个集群是否已经正常

kubectl get nodes -o wide

从上面的状态看，各个节点还没有网络启动，所以都是notReady状态。

3.安装flannel网络插件

下面命令用到的flannel插件可以 网盘下载到。https://pan.baidu.com/s/1yL_7EM-kEoqss12E1UDFXA 提取码: uikr

三台机器分别执行

master主机执行
拷贝cni plug执行程序
cp flannel /opt/cni/bin/
chmod 755 /opt/cni/bin/flannel
docker load < flanneld-v0.11.0-amd64.docker
kubectl delete -f kube-flannel.yml
kubectl apply -f kube-flannel.yml

worker主机执行
cp flannel /opt/cni/bin/
chmod 755 /opt/cni/bin/flannel
docker load < flanneld-v0.11.0-amd64.docker

这时候所有节点运行基本正常了，这样K8s安装成功

安装Prometheus

安装这个我们会启用Grafana的UI来查看Prometheus的数据展示。prometheus我们用的2.0.0,Grafana用的是4.2.0，node-exporter是收集所有节点信息的Pod。

为了安装方便，可以先把镜像拿下来

docker pull prom/node-exporter
docker pull prom/prometheus:v2.0.0
docker pull grafana/grafana:4.2.0

在拖完镜像后，现在我们就是要执行yaml来建立镜像了。

kubectl create -f  node-exporter.yaml 
kubectl create -f  rbac-setup.yaml
kubectl create -f  configmap.yaml 
kubectl create -f prometheus.deploy.yaml
kubectl create -f prometheus.svc.yaml
kubectl create -f grafana-deploy.yaml
kubectl create -f grafana-svc.yaml --validate=false
kubectl create -f grafana-ing.yaml

成功后执行kubectl get pod --all-namespaces，显示如下

先访问http://10.10.162.35:30003/ 查看Prometheus，看看target是否都是成功的。

如果这样就是，全部成功了

接下来我们配置,Grafana来查看Prometheus的数据内容。因为这里Grafana的nodeport是随机的，所以你可以看看哪些端口是开放的，可以访问一下，我这里是Grafana地址是http://10.10.162.35:32154/login，输入admin,admin默认用户名和密码

进入Grafana先配置数据源

然后配置dashboard


我这里导入的模板是
https://grafana.com/grafana/dashboards/315-kubernetes-cluster-monitoring-via-prometheus/

接下来就可以观看指标参数了。接下来我们会自己来定义其他的监控项。

node-exporter.yaml 内容如下

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: node-exporter
  namespace: kube-system
  labels:
    k8s-app: node-exporter
spec:
  selector:
    matchLabels:
      k8s-app: node-exporter
  template:
    metadata:
      labels:
        k8s-app: node-exporter
    spec:
      hostPID: true
      hostIPC: true
      hostNetwork: true
      containers:
      - image: prom/node-exporter
        name: node-exporter
        ports:
        - containerPort: 9100
          protocol: TCP
          name: http
        securityContext:
          privileged: true
        args:
        - --path.procfs
        - /host/proc
        - --path.sysfs
        - /host/sys
        - --collector.filesystem.ignored-mount-points
        - '"^/(sys|proc|dev|host|etc)($|/)"'
        volumeMounts:
        - name: dev
          mountPath: /host/dev
        - name: proc
          mountPath: /host/proc
        - name: sys
          mountPath: /host/sys
        - name: rootfs
          mountPath: /rootfs
      tolerations:
      - key: "node-role.kubernetes.io/master"
        operator: "Exists"
        effect: "NoSchedule"
      volumes:
        - name: proc
          hostPath:
            path: /proc
        - name: dev
          hostPath:
            path: /dev
        - name: sys
          hostPath:
            path: /sys
        - name: rootfs
          hostPath:
            path: /
---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: node-exporter
  name: node-exporter
  namespace: kube-system
spec:
  ports:
  - name: http
    port: 9100
    nodePort: 31672
    protocol: TCP
  type: NodePort
  selector:
    k8s-app: node-exporter

rbac-setup.yaml内容如下

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: prometheus
rules:
- apiGroups: [""]
  resources:
  - nodes
  - nodes/proxy
  - nodes/metrics
  - services
  - endpoints
  - pods
  verbs: ["get", "list", "watch"]
- apiGroups:
  - extensions
  resources:
  - ingresses
  verbs: ["get", "list", "watch"]
- nonResourceURLs: ["/metrics"]
  verbs: ["get"]
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: prometheus
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: prometheus
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: prometheus
subjects:
- kind: ServiceAccount
  name: prometheus
  namespace: kube-system

configmap.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: prometheus-config
  namespace: kube-system
data:
  prometheus.yml: |
    global:
      scrape_interval:     15s
      evaluation_interval: 15s
    scrape_configs:

    - job_name: 'kubernetes-apiservers'
      kubernetes_sd_configs:
      - role: endpoints
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - source_labels: [__meta_kubernetes_namespace, __meta_kubernetes_service_name, __meta_kubernetes_endpoint_port_name]
        action: keep
        regex: default;kubernetes;https

    - job_name: 'kubernetes-nodes'
      kubernetes_sd_configs:
      - role: node
      scheme: http
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
      - source_labels: [__address__]
        regex: '(.*):10250'
        replacement: '${1}:9100'
        target_label: __address__
        action: replace
      - source_labels: [__meta_kubernetes_node_name]
        regex: (.+)
        target_label: __metrics_path__
        replacement: /metrics

    - job_name: 'kubernetes-cadvisor'
      kubernetes_sd_configs:
      - role: node
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)
      - target_label: __address__
        replacement: kubernetes.default.svc:443
      - source_labels: [__meta_kubernetes_node_name]
        regex: (.+)
        target_label: __metrics_path__
        replacement: /api/v1/nodes/${1}/proxy/metrics/cadvisor

    - job_name: 'kubernetes-service-endpoints'
      kubernetes_sd_configs:
      - role: endpoints
      relabel_configs:
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scrape]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_scheme]
        action: replace
        target_label: __scheme__
        regex: (https?)
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_path]
        action: replace
        target_label: __metrics_path__
        regex: (.+)
      - source_labels: [__address__, __meta_kubernetes_service_annotation_prometheus_io_port]
        action: replace
        target_label: __address__
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: $1:$2
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        action: replace
        target_label: kubernetes_name

    - job_name: 'kubernetes-services'
      kubernetes_sd_configs:
      - role: service
      metrics_path: /probe
      params:
        module: [http_2xx]
      relabel_configs:
      - source_labels: [__meta_kubernetes_service_annotation_prometheus_io_probe]
        action: keep
        regex: true
      - source_labels: [__address__]
        target_label: __param_target
      - target_label: __address__
        replacement: blackbox-exporter.example.com:9115
      - source_labels: [__param_target]
        target_label: instance
      - action: labelmap
        regex: __meta_kubernetes_service_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_service_name]
        target_label: kubernetes_name

    - job_name: 'kubernetes-ingresses'
      kubernetes_sd_configs:
      - role: ingress
      relabel_configs:
      - source_labels: [__meta_kubernetes_ingress_annotation_prometheus_io_probe]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_ingress_scheme,__address__,__meta_kubernetes_ingress_path]
        regex: (.+);(.+);(.+)
        replacement: ${1}://${2}${3}
        target_label: __param_target
      - target_label: __address__
        replacement: blackbox-exporter.example.com:9115
      - source_labels: [__param_target]
        target_label: instance
      - action: labelmap
        regex: __meta_kubernetes_ingress_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_ingress_name]
        target_label: kubernetes_name

    - job_name: 'kubernetes-pods'
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_scrape]
        action: keep
        regex: true
      - source_labels: [__meta_kubernetes_pod_annotation_prometheus_io_path]
        action: replace
        target_label: __metrics_path__
        regex: (.+)
      - source_labels: [__address__, __meta_kubernetes_pod_annotation_prometheus_io_port]
        action: replace
        regex: ([^:]+)(?::\d+)?;(\d+)
        replacement: $1:$2
        target_label: __address__
      - action: labelmap
        regex: __meta_kubernetes_pod_label_(.+)
      - source_labels: [__meta_kubernetes_namespace]
        action: replace
        target_label: kubernetes_namespace
      - source_labels: [__meta_kubernetes_pod_name]
        action: replace
        target_label: kubernetes_pod_name
    
    - job_name: 'kubernetes-kubelet'
      kubernetes_sd_configs:
      - role: node
      scheme: https
      tls_config:
        ca_file: /var/run/secrets/kubernetes.io/serviceaccount/ca.crt
        insecure_skip_verify: true
      bearer_token_file: /var/run/secrets/kubernetes.io/serviceaccount/token
      relabel_configs:
      - action: labelmap
        regex: __meta_kubernetes_node_label_(.+)

prometheus.deploy.yaml

---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    name: prometheus-deployment
  name: prometheus
  namespace: kube-system
spec:
  replicas: 1
  selector:
    matchLabels:
      app: prometheus
  template:
    metadata:
      labels:
        app: prometheus
    spec:
      containers:
      - image: prom/prometheus:v2.0.0
        name: prometheus
        command:
        - "/bin/prometheus"
        args:
        - "--config.file=/etc/prometheus/prometheus.yml"
        - "--storage.tsdb.path=/prometheus"
        - "--storage.tsdb.retention=7d"
        - "--web.enable-admin-api"
        - "--web.enable-lifecycle"
        ports:
        - containerPort: 9090
          protocol: TCP
        volumeMounts:
        - mountPath: "/prometheus"
          name: data
        - mountPath: "/etc/prometheus"
          name: config-volume
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
          limits:
            cpu: 500m
            memory: 2500Mi
      serviceAccountName: prometheus    
      volumes:
      - name: data
        emptyDir: {}
      - name: config-volume
        configMap:
          name: prometheus-config

prometheus.svc.yaml

---
kind: Service
apiVersion: v1
metadata:
  labels:
    app: prometheus
  name: prometheus
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port: 9090
    targetPort: 9090
    nodePort: 30003
  selector:
    app: prometheus

grafana-deploy.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: grafana-core
  namespace: kube-system
  labels:
    app: grafana
    component: core
spec:
  replicas: 1
  selector:
    matchLabels:
      app: grafana
      component: core
  template:
    metadata:
      labels:
        app: grafana
        component: core
    spec:
      containers:
      - image: grafana/grafana:4.2.0
        name: grafana-core
        imagePullPolicy: IfNotPresent
        # env:
        resources:
          # keep request = limit to keep this container in guaranteed class
          limits:
            cpu: 100m
            memory: 100Mi
          requests:
            cpu: 100m
            memory: 100Mi
        env:
          # The following env variables set up basic auth twith the default admin user and admin password.
          - name: GF_AUTH_BASIC_ENABLED
            value: "true"
          - name: GF_AUTH_ANONYMOUS_ENABLED
            value: "false"
          # - name: GF_AUTH_ANONYMOUS_ORG_ROLE
          #   value: Admin
          # does not really work, because of template variables in exported dashboards:
          # - name: GF_DASHBOARDS_JSON_ENABLED
          #   value: "true"
        readinessProbe:
          httpGet:
            path: /login
            port: 3000
          # initialDelaySeconds: 30
          # timeoutSeconds: 1
        volumeMounts:
        - name: grafana-persistent-storage
          mountPath: /var
      volumes:
      - name: grafana-persistent-storage
        emptyDir: {}

grafana-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: grafana
  namespace: kube-system
  labels:
    app: grafana
    component: core
spec:
  type: NodePort
  ports:
    - port: 3000
  selector:
    app: grafana
component: core

grafana-ing.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
   name: grafana
   namespace: kube-system
spec:
   rules:
   - host: k8s.grafana
     http:
       paths:
       - path: /
         backend:
          serviceName: grafana
          servicePort: 3000