Kubernetes K8S之kube-prometheus概述与部署

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Kubernetes K8S之kube-prometheus概述与部署

主机配置规划

服务器名称(hostname) 系统版本 配置 内网IP 外网IP(模拟)
k8s-master CentOS7.7 2C/4G/20G 172.16.1.110 10.0.0.110
k8s-node01 CentOS7.7 2C/4G/20G 172.16.1.111 10.0.0.111
k8s-node02 CentOS7.7 2C/4G/20G 172.16.1.112 10.0.0.112

prometheus概述

Prometheus是一个开源的系统监控和警报工具包，自2012成立以来，许多公司和组织采用了Prometheus。它现在是一个独立的开源项目，并独立于任何公司维护。在2016年，Prometheus加入云计算基金会作为Kubernetes之后的第二托管项目。

Prometheus性能也足够支撑上万台规模的集群。

Prometheus的关键特性

  • 多维度数据模型
  • 灵活的查询语言
  • 不依赖于分布式存储；单服务器节点是自治的
  • 通过基于HTTP的pull方式采集时序数据
  • 可以通过中间网关进行时序列数据推送
  • 通过服务发现或者静态配置来发现目标服务对象
  • 支持多种多样的图表和界面展示，比如Grafana等

架构图

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基本原理

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)。

Prometheus三大套件

  • Server 主要负责数据采集和存储，提供PromQL查询语言的支持。
  • Alertmanager 警告管理器，用来进行报警。
  • Push Gateway 支持临时性Job主动推送指标的中间网关。

服务过程

  • Prometheus Daemon负责定时去目标上抓取metrics(指标)数据，每个抓取目标需要暴露一个http服务的接口给它定时抓取。Prometheus支持通过配置文件、文本文件、Zookeeper、Consul、DNS SRV Lookup等方式指定抓取目标。Prometheus采用PULL的方式进行监控，即服务器可以直接通过目标PULL数据或者间接地通过中间网关来Push数据。
  • Prometheus在本地存储抓取的所有数据，并通过一定规则进行清理和整理数据，并把得到的结果存储到新的时间序列中。
  • Prometheus通过PromQL和其他API可视化地展示收集的数据。Prometheus支持很多方式的图表可视化，例如Grafana、自带的Promdash以及自身提供的模版引擎等等。Prometheus还提供HTTP API的查询方式，自定义所需要的输出。
  • PushGateway支持Client主动推送metrics到PushGateway，而Prometheus只是定时去Gateway上抓取数据。
  • Alertmanager是独立于Prometheus的一个组件，可以支持Prometheus的查询语句，提供十分灵活的报警方式。

kube-prometheus部署

kube-prometheus的GitHub地址：

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https://github.com/coreos/kube-prometheus/

本次我们选择release-0.2版本，而不是其他版本。

kube-prometheus下载与配置修改

下载

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[root@k8s-master prometheus]# pwd
/root/k8s_practice/prometheus
[root@k8s-master prometheus]# 
[root@k8s-master prometheus]# wget https://github.com/coreos/kube-prometheus/archive/v0.2.0.tar.gz 
[root@k8s-master prometheus]# tar xf v0.2.0.tar.gz 
[root@k8s-master prometheus]# ll
total 432
drwxrwxr-x 10 root root   4096 Sep 13  2019 kube-prometheus-0.2.0
-rw-r--r--  1 root root 200048 Jul 19 11:41 v0.2.0.tar.gz

配置修改

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# 当前所在目录
[root@k8s-master manifests]# pwd
/root/k8s_practice/prometheus/kube-prometheus-0.2.0/manifests
[root@k8s-master manifests]# 
# 配置修改1
[root@k8s-master manifests]# vim grafana-service.yaml 
apiVersion: v1
kind: Service
metadata:
  labels:
    app: grafana
  name: grafana
  namespace: monitoring
spec:
  type: NodePort   # 添加内容
  ports:
  - name: http
    port: 3000
    targetPort: http
    nodePort: 30100   # 添加内容
  selector:
    app: grafana
[root@k8s-master manifests]# 
# 配置修改2 
[root@k8s-master manifests]# vim prometheus-service.yaml 
apiVersion: v1
kind: Service
metadata:
  labels:
    prometheus: k8s
  name: prometheus-k8s
  namespace: monitoring
spec:
  type: NodePort   # 添加内容
  ports:
  - name: web
    port: 9090
    targetPort: web
    nodePort: 30200   # 添加内容
  selector:
    app: prometheus
    prometheus: k8s
  sessionAffinity: ClientIP
[root@k8s-master manifests]#
# 配置修改3
[root@k8s-master manifests]# vim alertmanager-service.yaml 
apiVersion: v1
kind: Service
metadata:
  labels:
    alertmanager: main
  name: alertmanager-main
  namespace: monitoring
spec:
  type: NodePort   # 添加内容
  ports:
  - name: web
    port: 9093
    targetPort: web
    nodePort: 30300   # 添加内容
  selector:
    alertmanager: main
    app: alertmanager
  sessionAffinity: ClientIP
[root@k8s-master manifests]#
# 配置修改4
[root@k8s-master manifests]# vim grafana-deployment.yaml 
# 将apps/v1beta2 改为 apps/v1
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: grafana
  name: grafana
  namespace: monitoring
spec:
  replicas: 1
  selector:
………………

kube-prometheus镜像版本查看与下载

由于镜像都在国外，因此经常会下载失败。为了快速下载镜像，这里我们下载国内的镜像，然后tag为配置文件中的国外镜像名即可。

查看kube-prometheus的镜像信息

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# 当前工作目录
[root@k8s-master manifests]# pwd
/root/k8s_practice/prometheus/kube-prometheus-0.2.0/manifests
[root@k8s-master manifests]# 
# 所有镜像信息如下
[root@k8s-master manifests]# grep -riE 'quay.io|k8s.gcr|grafana/' *
0prometheus-operator-deployment.yaml:        - --config-reloader-image=quay.io/coreos/configmap-reload:v0.0.1
0prometheus-operator-deployment.yaml:        - --prometheus-config-reloader=quay.io/coreos/prometheus-config-reloader:v0.33.0
0prometheus-operator-deployment.yaml:        image: quay.io/coreos/prometheus-operator:v0.33.0
alertmanager-alertmanager.yaml:  baseImage: quay.io/prometheus/alertmanager
grafana-deployment.yaml:      - image: grafana/grafana:6.2.2
kube-state-metrics-deployment.yaml:        image: quay.io/coreos/kube-rbac-proxy:v0.4.1
kube-state-metrics-deployment.yaml:        image: quay.io/coreos/kube-rbac-proxy:v0.4.1
kube-state-metrics-deployment.yaml:        image: quay.io/coreos/kube-state-metrics:v1.7.2
kube-state-metrics-deployment.yaml:        image: k8s.gcr.io/addon-resizer:1.8.4
node-exporter-daemonset.yaml:        image: quay.io/prometheus/node-exporter:v0.18.1
node-exporter-daemonset.yaml:        image: quay.io/coreos/kube-rbac-proxy:v0.4.1
prometheus-adapter-deployment.yaml:        image: quay.io/coreos/k8s-prometheus-adapter-amd64:v0.4.1
prometheus-prometheus.yaml:  baseImage: quay.io/prometheus/prometheus
##### 由上可知alertmanager和prometheus的镜像版本未显示
### 获取alertmanager镜像版本信息
[root@k8s-master manifests]# cat alertmanager-alertmanager.yaml 
apiVersion: monitoring.coreos.com/v1
kind: Alertmanager
metadata:
  labels:
    alertmanager: main
  name: main
  namespace: monitoring
spec:
  baseImage: quay.io/prometheus/alertmanager
  nodeSelector:
    kubernetes.io/os: linux
  replicas: 3
  securityContext:
    fsGroup: 2000
    runAsNonRoot: true
    runAsUser: 1000
  serviceAccountName: alertmanager-main
  version: v0.18.0
##### 由上可见alertmanager的镜像版本为v0.18.0
### 获取prometheus镜像版本信息
[root@k8s-master manifests]# cat prometheus-prometheus.yaml
apiVersion: monitoring.coreos.com/v1
kind: Prometheus
metadata:
  labels:
    prometheus: k8s
  name: k8s
  namespace: monitoring
spec:
  alerting:
    alertmanagers:
    - name: alertmanager-main
      namespace: monitoring
      port: web
  baseImage: quay.io/prometheus/prometheus
  nodeSelector:
    kubernetes.io/os: linux
  podMonitorSelector: {}
  replicas: 2
  resources:
    requests:
      memory: 400Mi
  ruleSelector:
    matchLabels:
      prometheus: k8s
      role: alert-rules
  securityContext:
    fsGroup: 2000
    runAsNonRoot: true
    runAsUser: 1000
  serviceAccountName: prometheus-k8s
  serviceMonitorNamespaceSelector: {}
  serviceMonitorSelector: {}
  version: v2.11.0
##### 由上可见prometheus的镜像版本为v2.11.0

执行脚本：镜像下载并重命名【集群所有机器执行】

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[root@k8s-master software]# vim download_prometheus_image.sh 
#!/bin/sh

##### 在 master 节点和 worker 节点都要执行 【所有机器执行】

# 加载环境变量
. /etc/profile
. /etc/bashrc

###############################################
# 从国内下载 prometheus 所需镜像，并对镜像重命名  
src_registry="registry.cn-beijing.aliyuncs.com/cloud_registry"
# 定义镜像集合数组 
images=(
    kube-rbac-proxy:v0.4.1
    kube-state-metrics:v1.7.2
    k8s-prometheus-adapter-amd64:v0.4.1
    configmap-reload:v0.0.1
    prometheus-config-reloader:v0.33.0
    prometheus-operator:v0.33.0
)
# 循环从国内获取的Docker镜像
for img in ${images[@]};
do
    # 从国内源下载镜像
    docker pull ${src_registry}/$img
    # 改变镜像名称
    docker tag  ${src_registry}/$img quay.io/coreos/$img
    # 删除源始镜像
    docker rmi  ${src_registry}/$img
    # 打印分割线
    echo "======== $img download OK  ========"
done

##### 其他镜像下载
image_name="alertmanager:v0.18.0"
docker pull ${src_registry}/${image_name}  && docker tag ${src_registry}/${image_name}  quay.io/prometheus/${image_name}  && docker rmi ${src_registry}/${image_name}
echo "======== ${image_name} download OK  ========"

image_name="node-exporter:v0.18.1"
docker pull ${src_registry}/${image_name}  && docker tag ${src_registry}/${image_name}  quay.io/prometheus/${image_name}  && docker rmi ${src_registry}/${image_name}
echo "======== ${image_name} download OK  ========"

image_name="prometheus:v2.11.0"
docker pull ${src_registry}/${image_name}  && docker tag ${src_registry}/${image_name}  quay.io/prometheus/${image_name}  && docker rmi ${src_registry}/${image_name}
echo "======== ${image_name} download OK  ========"

image_name="grafana:6.2.2"
docker pull ${src_registry}/${image_name}  && docker tag ${src_registry}/${image_name}  grafana/${image_name}             && docker rmi ${src_registry}/${image_name}
echo "======== ${image_name} download OK  ========"

image_name="addon-resizer:1.8.4"
docker pull ${src_registry}/${image_name}  && docker tag ${src_registry}/${image_name}  k8s.gcr.io/${image_name}          && docker rmi ${src_registry}/${image_name}
echo "======== ${image_name} download OK  ========"


echo "********** prometheus docker images OK! **********"

执行脚本后得到如下镜像

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[root@k8s-master software]# docker images | grep 'quay.io/coreos'
quay.io/coreos/kube-rbac-proxy                             v0.4.1                           a9d1a87e4379        6 days ago          41.3MB
quay.io/coreos/flannel                                     v0.12.0-amd64                    4e9f801d2217        4 months ago        52.8MB ## 之前已存在
quay.io/coreos/kube-state-metrics                          v1.7.2                           3fd71b84d250        6 months ago        33.1MB
quay.io/coreos/prometheus-config-reloader                  v0.33.0                          64751efb2200        8 months ago        17.6MB
quay.io/coreos/prometheus-operator                         v0.33.0                          8f2f814d33e1        8 months ago        42.1MB
quay.io/coreos/k8s-prometheus-adapter-amd64                v0.4.1                           5f0fc84e586c        15 months ago       60.7MB
quay.io/coreos/configmap-reload                            v0.0.1                           3129a2ca29d7        3 years ago         4.79MB
[root@k8s-master software]# 
[root@k8s-master software]# docker images | grep 'quay.io/prometheus'
quay.io/prometheus/node-exporter                           v0.18.1                          d7707e6f5e95        11 days ago         22.9MB
quay.io/prometheus/prometheus                              v2.11.0                          de242295e225        2 months ago        126MB
quay.io/prometheus/alertmanager                            v0.18.0                          30594e96cbe8        10 months ago       51.9MB
[root@k8s-master software]# 
[root@k8s-master software]# docker images | grep 'grafana'
grafana/grafana                                            6.2.2                            a532fe3b344a        9 months ago        248MB
[root@k8s-node01 software]# 
[root@k8s-node01 software]# docker images | grep 'addon-resizer'
k8s.gcr.io/addon-resizer                                   1.8.4                            5ec630648120        20 months ago       38.3MB

kube-prometheus启动

启动prometheus

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[root@k8s-master kube-prometheus-0.2.0]# pwd
/root/k8s_practice/prometheus/kube-prometheus-0.2.0
[root@k8s-master kube-prometheus-0.2.0]# 
### 如果出现异常，可以再重复执行一次或多次
[root@k8s-master kube-prometheus-0.2.0]# kubectl apply -f manifests/

启动后svc与pod状态查看

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[root@k8s-master ~]# kubectl top node
NAME         CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%   
k8s-master   152m         7%     1311Mi          35%       
k8s-node01   100m         5%     928Mi           54%       
k8s-node02   93m          4%     979Mi           56%       
[root@k8s-master ~]# 
[root@k8s-master ~]# kubectl get svc -n monitoring
NAME                    TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)                      AGE
alertmanager-main       NodePort    10.97.249.249    <none>        9093:30300/TCP               7m21s
alertmanager-operated   ClusterIP   None             <none>        9093/TCP,9094/TCP,9094/UDP   7m13s
grafana                 NodePort    10.101.183.103   <none>        3000:30100/TCP               7m20s
kube-state-metrics      ClusterIP   None             <none>        8443/TCP,9443/TCP            7m20s
node-exporter           ClusterIP   None             <none>        9100/TCP                     7m20s
prometheus-adapter      ClusterIP   10.105.174.86    <none>        443/TCP                      7m19s
prometheus-k8s          NodePort    10.109.179.233   <none>        9090:30200/TCP               7m19s
prometheus-operated     ClusterIP   None             <none>        9090/TCP                     7m3s
prometheus-operator     ClusterIP   None             <none>        8080/TCP                     7m21s
[root@k8s-master ~]# 
[root@k8s-master ~]# kubectl get pod -n monitoring -o wide
NAME                                  READY   STATUS    RESTARTS   AGE     IP             NODE         NOMINATED NODE   READINESS GATES
alertmanager-main-0                   2/2     Running   0          2m11s   10.244.4.164   k8s-node01   <none>           <none>
alertmanager-main-1                   2/2     Running   0          2m11s   10.244.2.225   k8s-node02   <none>           <none>
alertmanager-main-2                   2/2     Running   0          2m11s   10.244.4.163   k8s-node01   <none>           <none>
grafana-5cd56df4cd-6d75r              1/1     Running   0          29s     10.244.2.227   k8s-node02   <none>           <none>
kube-state-metrics-7d4bb66d8d-gx7w4   4/4     Running   0          2m18s   10.244.2.223   k8s-node02   <none>           <none>
node-exporter-pl47v                   2/2     Running   0          2m17s   172.16.1.110   k8s-master   <none>           <none>
node-exporter-tmmbw                   2/2     Running   0          2m17s   172.16.1.111   k8s-node01   <none>           <none>
node-exporter-w8wd9                   2/2     Running   0          2m17s   172.16.1.112   k8s-node02   <none>           <none>
prometheus-adapter-c676d8764-phj69    1/1     Running   0          2m17s   10.244.2.224   k8s-node02   <none>           <none>
prometheus-k8s-0                      3/3     Running   1          2m1s    10.244.2.226   k8s-node02   <none>           <none>
prometheus-k8s-1                      3/3     Running   0          2m1s    10.244.4.165   k8s-node01   <none>           <none>
prometheus-operator-7559d67ff-lk86l   1/1     Running   0          2m18s   10.244.4.162   k8s-node01   <none>           <none>

kube-prometheus访问

prometheus-service访问

访问地址如下：

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http://172.16.1.110:30200/

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通过访问如下地址，可以看到prometheus已经成功连接上了k8s的apiserver。

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http://172.16.1.110:30200/targets

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查看service-discovery

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http://172.16.1.110:30200/service-discovery

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prometheus自己指标查看

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http://172.16.1.110:30200/metrics

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prometheus的WEB界面上提供了基本的查询，例如查询K8S集群中每个POD的CPU使用情况，可以使用如下查询条件查询：

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# 直接使用 container_cpu_usage_seconds_total 可以看见有哪些字段信息
sum(rate(container_cpu_usage_seconds_total{image!="", pod!=""}[1m] )) by (pod)

列表页面

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图形页面

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grafana-service访问

访问地址如下：

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http://172.16.1.110:30100/

首次登录时账号密码默认为：admin/admin

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添加数据来源

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得到如下页面

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如上，数据来源默认是已经添加好了的

点击进入，拉到下面，再点击Test按钮，测验数据来源是否正常

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之后可导入一些模板

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数据信息图像化查看

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异常问题解决

如果 kubectl apply -f manifests/ 出现类似如下提示：

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unable to recognize "manifests/alertmanager-alertmanager.yaml": no matches for kind "Alertmanager" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/alertmanager-serviceMonitor.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/grafana-serviceMonitor.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/kube-state-metrics-serviceMonitor.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/node-exporter-serviceMonitor.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-operator-serviceMonitor.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-prometheus.yaml": no matches for kind "Prometheus" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-rules.yaml": no matches for kind "PrometheusRule" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-serviceMonitor.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-serviceMonitorApiserver.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-serviceMonitorCoreDNS.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-serviceMonitorKubeControllerManager.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-serviceMonitorKubeScheduler.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"
unable to recognize "manifests/prometheus-serviceMonitorKubelet.yaml": no matches for kind "ServiceMonitor" in version "monitoring.coreos.com/v1"

那么再次 kubectl apply -f manifests/ 即可；因为存在依赖。

但如果使用的是kube-prometheus：v0.3.0、v0.4.0、v0.5.0版本并出现了上面的提示【反复执行kubectl apply -f manifests/，但一直存在】，原因暂不清楚。

完毕！

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