Kubernetes集群监控方案-原创手记-慕课网

本文介绍在k8s集群中使用node-exporter、prometheus、grafana对集群进行监控。

其实现原理有点类似ELK、EFK组合。node-exporter组件负责收集节点上的metrics监控数据，并将数据推送给prometheus, prometheus负责存储这些数据，grafana将这些数据通过网页以图形的形式展现给用户。

在开始之前有必要了解下Prometheus是什么?

Prometheus （中文名：普罗米修斯）是由 SoundCloud 开发的开源监控报警系统和时序列数据库(TSDB).自2012年起,许多公司及组织已经采用 Prometheus,并且该项目有着非常活跃的开发者和用户社区.现在已经成为一个独立的开源项目。Prometheus 在2016加入 CNCF ( Cloud Native Computing Foundation ), 作为在 kubernetes 之后的第二个由基金会主持的项目。 Prometheus 的实现参考了Google内部的监控实现，与源自Google的Kubernetes结合起来非常合适。另外相比influxdb的方案，性能更加突出，而且还内置了报警功能。它针对大规模的集群环境设计了拉取式的数据采集方式，只需要在应用里面实现一个metrics接口，然后把这个接口告诉Prometheus就可以完成数据采集了，下图为prometheus的架构图。

Kubernetes集群监控方案

Prometheus的特点：

1、多维数据模型（时序列数据由metric名和一组key/value组成）

2、在多维度上灵活的查询语言(PromQl)

3、不依赖分布式存储，单主节点工作.

4、通过基于HTTP的pull方式采集时序数据

5、可以通过中间网关进行时序列数据推送(pushing)

6、目标服务器可以通过发现服务或者静态配置实现

7、多种可视化和仪表盘支持

prometheus 相关组件，Prometheus生态系统由多个组件组成，其中许多是可选的：

1、Prometheus 主服务,用来抓取和存储时序数据

2、client library 用来构造应用或 exporter 代码 (go,java,python,ruby)

3、push 网关可用来支持短连接任务

4、可视化的dashboard (两种选择,promdash 和 grafana.目前主流选择是 grafana.)

4、一些特殊需求的数据出口(用于HAProxy, StatsD, Graphite等服务)

5、实验性的报警管理端(alartmanager,单独进行报警汇总,分发,屏蔽等 )

promethues 的各个组件基本都是用 golang 编写,对编译和部署十分友好.并且没有特殊依赖.基本都是独立工作。

上述文字来自网络！

现在我们正式开始部署工作。

一、环境介绍

操作系统环境：centos linux 7.2 64bit

K8S软件版本： 1.9.0（采用kubeadm方式部署）

Master节点IP： 192.168.115.5/24

Node节点IP： 192.168.115.6/24

二、在k8s集群的所有节点上下载所需要的image

# docker pull prom/node-exporter

# docker pull prom/prometheus:v2.0.0

# docker pull grafana/grafana:4.2.0

三、采用daemonset方式部署node-exporter组件

# cat node-exporter.yaml

---

apiVersion: extensions/v1beta1

kind: DaemonSet

metadata:

namespace: kube-system

labels:

k8s-app: node-exporter

spec:

template:

metadata:

labels:

k8s-app: node-exporter

spec:

containers:

- image: prom/node-exporter

ports:

- containerPort: 9100

protocol: TCP

---

apiVersion: v1

kind: Service

metadata:

labels:

k8s-app: node-exporter

namespace: kube-system

spec:

ports:

- name: http

port: 9100

nodePort: 31672

protocol: TCP

type: NodePort

selector:

k8s-app: node-exporter

通过上述文件创建pod和service

# kubectl create -f node-exporter.yaml

四、部署prometheus组件

1、rbac文件

# cat rbac-setup.yaml

apiVersion: rbac.authorization.k8s.io/v1

kind: ClusterRole

metadata:

rules:

- apiGroups: [""]

resources:

- nodes

- nodes/proxy

- services

- endpoints

- pods

verbs: ["get", "list", "watch"]

- apiGroups:

- extensions

resources:

- ingresses

verbs: ["get", "list", "watch"]

- nonResourceURLs: ["/metrics"]

verbs: ["get"]

---

apiVersion: v1

kind: ServiceAccount

metadata:

namespace: kube-system

---

apiVersion: rbac.authorization.k8s.io/v1

kind: ClusterRoleBinding

metadata:

roleRef:

apiGroup: rbac.authorization.k8s.io

kind: ClusterRole

subjects:

- kind: ServiceAccount

namespace: kube-system

2、以configmap的形式管理prometheus组件的配置文件

# cat configmap.yaml

apiVersion: v1

kind: ConfigMap

metadata:

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: 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

- 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

3、Prometheus deployment 文件

# cat prometheus.deploy.yml

---

apiVersion: apps/v1beta2

kind: Deployment

metadata:

labels:

namespace: kube-system

spec:

replicas: 1

selector:

matchLabels:

app: prometheus

template:

metadata:

labels:

app: prometheus

spec:

containers:

- image: prom/prometheus:v2.0.0

command:

- "/bin/prometheus"

args:

- "--config.file=/etc/prometheus/prometheus.yml"

- "--storage.tsdb.path=/prometheus"

- "--storage.tsdb.retention=24h"

ports:

- containerPort: 9090

protocol: TCP

volumeMounts:

- mountPath: "/prometheus"

- mountPath: "/etc/prometheus"

resources:

requests:

cpu: 100m

memory: 100Mi

limits:

cpu: 500m

memory: 2500Mi

serviceAccountName: prometheus

volumes:

- name: data

emptyDir: {}

- name: config-volume

configMap:

4、Prometheus service文件

# cat prometheus.svc.yml

---

kind: Service

apiVersion: v1

metadata:

labels:

app: prometheus

namespace: kube-system

spec:

type: NodePort

ports:

- port: 9090

targetPort: 9090

nodePort: 30003

selector:

app: prometheus

5、通过上述yaml文件创建相应的对象

# kubectl create -f rbac-setup.yaml

# kubectl create -f configmap.yaml

# kubectl create -f prometheus.deploy.yml

# kubectl create -f prometheus.svc.yml

Kubernetes集群监控方案

Node-exporter对应的nodeport端口为31672，通过访问http://192.168.115.5:31672/metrics 可以看到对应的metrics

Kubernetes集群监控方案

prometheus对应的nodeport端口为30003，通过访问http://192.168.115.5:30003/target 可以看到prometheus已经成功连接上了k8s的apiserver

Kubernetes集群监控方案

可以在prometheus的WEB界面上提供了基本的查询K8S集群中每个POD的CPU使用情况，查询条件如下：

sum by (pod_name)( rate(container_cpu_usage_seconds_total{image!="", pod_name!=""}[1m] ) )

Kubernetes集群监控方案

上述的查询有出现数据，说明node-exporter往prometheus中写入数据正常，接下来我们就可以部署grafana组件，实现更友好的webui展示数据了。

五、部署grafana组件

1、grafana deployment配置文件

# cat grafana-deploy.yaml

apiVersion: extensions/v1beta1

kind: Deployment

metadata:

namespace: kube-system

labels:

app: grafana

component: core

spec:

replicas: 1

template:

metadata:

labels:

app: grafana

component: core

spec:

containers:

- image: grafana/grafana:4.2.0

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: {}

2、grafana service配置文件

# cat grafana-svc.yaml

apiVersion: v1

kind: Service

metadata:

namespace: kube-system

labels:

app: grafana

component: core

spec:

type: NodePort

ports:

- port: 3000

selector:

app: grafana

component: core

3、grafana ingress配置文件

# cat grafana-ing.yaml

apiVersion: extensions/v1beta1

kind: Ingress

metadata:

namespace: kube-system

spec:

rules:

- host: k8s.grafana

http:

paths:

- path: /

backend:

serviceName: grafana

servicePort: 3000

通过访问traefik的webui可以看到k8s.grafana服务发布成功

Kubernetes集群监控方案

修改hosts解析，访问测试

Kubernetes集群监控方案

也可以直接访问nodeport端口

Kubernetes集群监控方案

默认用户名和密码都是admin

Kubernetes集群监控方案

配置数据源为prometheus

Kubernetes集群监控方案

导入面板，可以直接输入模板编号315在线导入，或者下载好对应的json模板文件本地导入，面板模板下载地址https://grafana.com/dashboards/315

Kubernetes集群监控方案

导入面板之后就可以看到对应的监控数据了。

Kubernetes集群监控方案

这里要说明一下，在测试过程中，导入编号为162的模板，发现只有部分数据，且pod的名称显示不友好。模板地址https://grafana.com/dashboards/162，详见下图。

Kubernetes集群监控方案

六、后记

这里存在一些问题后续要继续研究解决。

1、prometheus的数据存储采用emptydir。如果Pod被删除，或者Pod发生迁移，emptyDir也会被删除，并且永久丢失。后续可以在K8S集群外部再配置一个Prometheus系统来永久保存监控数据，两个prometheus系统之间通过配置job自动进行数据拉取。

2、Grafana的配置数据存储采用emptydir。如果Pod被删除，或者Pod发生迁移，emptyDir也会被删除，并且永久丢失。我们也可以选择将grafana配置在k8s外部，数据源选择K8S集群外部的prometheus即可。

3、关于监控项的报警（alertmanager）尚未配置。

参考文档，感谢作者分享！

https://www.kubernetes.org.cn/3418.html

https://blog.qikqiak.com/post/kubernetes-monitor-prometheus-grafana/

https://github.com/giantswarm/kubernetes-prometheus/tree/master/manifests

https://segmentfault.com/a/1190000013245394

k8s监控prometheus Kubernetes