Kubernetes集群監控方案
其實現原理有點類似ELK、EFK組合。node-exporter組件負責收集節點上的metrics監控數據,並將數據推送給prometheus, prometheus負責存儲這些數據,grafana將這些數據通過網頁以圖形的形式展現給用戶。
在開始之前有必要了解下Prometheus是什麽?
Prometheus (中文名:普羅米修斯)是由 SoundCloud 開發的開源監控報警系統和時序列數據庫(TSDB).自2012年起,許多公司及組織已經采用 Prometheus,並且該項目有著非常活躍的開發者和用戶社區.現在已經成為一個獨立的開源項目。Prometheus 在2016加入 CNCF ( Cloud Native Computing Foundation ), 作為在 kubernetes 之後的第二個由基金會主持的項目。 Prometheus 的實現參考了Google內部的監控實現,與源自Google的Kubernetes結合起來非常合適。另外相比influxdb的方案,性能更加突出,而且還內置了報警功能。它針對大規模的集群環境設計了拉取式的數據采集方式,只需要在應用裏面實現一個metrics接口,然後把這個接口告訴Prometheus就可以完成數據采集了,下圖為prometheus的架構圖。
Prometheus的特點:
1、多維數據模型(時序列數據由metric名和一組key/value組成)
2、在多維度上靈活的查詢語言(PromQl)
3、不依賴分布式存儲,單主節點工作.
4、通過基於HTTP的pull方式采集時序數據
5、可以通過中間網關進行時序列數據推送(pushing)
6、目標服務器可以通過發現服務或者靜態配置實現
7、多種可視化和儀表盤支持
prometheus 相關組件,Prometheus生態系統由多個組件組成,其中許多是可選的:
1、Prometheus 主服務,用來抓取和存儲時序數據
2、client library 用來構造應用或 exporter 代碼 (go,java,python,ruby)
4、可視化的dashboard (兩種選擇,promdash 和 grafana.目前主流選擇是 grafana.)
4、一些特殊需求的數據出口(用於HAProxy, StatsD, Graphite等服務)
5、實驗性的報警管理端(alartmanager,單獨進行報警匯總,分發,屏蔽等 )
promethues 的各個組件基本都是用 golang 編寫,對編譯和部署十分友好.並且沒有特殊依賴.基本都是獨立工作。
上述文字來自網絡!
現在我們正式開始部署工作。
一、環境介紹
操作系統環境:centos linux 7.2 64bit
K8S軟件版本: 1.9.0(采用kubeadm方式部署)
Node節點IP: 192.168.115.6/24
二、在k8s集群的所有節點上下載所需要的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組件
# cat node-exporter.yaml
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
name: node-exporter
namespace: kube-system
labels:
k8s-app: node-exporter
spec:
template:
metadata:
labels:
k8s-app: node-exporter
spec:
containers:
- image: prom/node-exporter
name: node-exporter
ports:
- containerPort: 9100
protocol: TCP
name: http
---
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
通過上述文件創建pod和service
# kubectl create -f node-exporter.yaml
四、部署prometheus組件
1、rbac文件
# cat rbac-setup.yaml
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
name: prometheus
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:
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
2、以configmap的形式管理prometheus組件的配置文件
# cat 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: 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:
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=24h"
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
4、Prometheus service文件
# cat prometheus.svc.yml
---
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
5、通過上述yaml文件創建相應的對象
# kubectl create -f rbac-setup.yaml
# kubectl create -f configmap.yaml
# kubectl create -f prometheus.deploy.yml
# kubectl create -f prometheus.svc.yml
Node-exporter對應的nodeport端口為31672,通過訪問http://192.168.115.5:31672/metrics 可以看到對應的metrics
prometheus對應的nodeport端口為30003,通過訪問http://192.168.115.5:30003/target 可以看到prometheus已經成功連接上了k8s的apiserver
可以在prometheus的WEB界面上提供了基本的查詢K8S集群中每個POD的CPU使用情況,查詢條件如下:
sum by (pod_name)( rate(container_cpu_usage_seconds_total{image!="", pod_name!=""}[1m] ) )
上述的查詢有出現數據,說明node-exporter往prometheus中寫入數據正常,接下來我們就可以部署grafana組件,實現更友好的webui展示數據了。
五、部署grafana組件
1、grafana deployment配置文件
# cat grafana-deploy.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: grafana-core
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
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: {}
2、grafana service配置文件
# cat 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
3、grafana ingress配置文件
# cat 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
通過訪問traefik的webui可以看到k8s.grafana服務發布成功
修改hosts解析,訪問測試
也可以直接訪問nodeport端口
默認用戶名和密碼都是admin
配置數據源為prometheus
導入面板,可以直接輸入模板編號315在線導入,或者下載好對應的json模板文件本地導入,面板模板下載地址https://grafana.com/dashboards/315
導入面板之後就可以看到對應的監控數據了。
這裏要說明一下,在測試過程中,導入編號為162的模板,發現只有部分數據,且pod的名稱顯示不友好。模板地址https://grafana.com/dashboards/162,詳見下圖。
六、後記
這裏存在一些問題後續要繼續研究解決。
1、prometheus的數據存儲采用emptydir。如果Pod被刪除,或者Pod發生遷移,emptyDir也會被刪除,並且永久丟失。後續可以在K8S集群外部再配置一個Prometheus系統來永久保存監控數據, 兩個prometheus系統之間通過配置job自動進行數據拉取。
2、Grafana的配置數據存儲采用emptydir。如果Pod被刪除,或者Pod發生遷移,emptyDir也會被刪除,並且永久丟失。我們也可以選擇將grafana配置在k8s外部,數據源選擇K8S集群外部的prometheus即可。
3、關於監控項的報警(alertmanager)尚未配置。
參考文檔,感謝作者分享!
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
Kubernetes集群監控方案