K8S资源管理总结及dashboard创建

K8S资源管理总结及dashboard创建

K8S核心资源管理方法：

• 陈述式管理：基于众多kubectl命令


• 声明式管理：基于k8s资源配置清单


• GUI式管理：基于K8S仪表盘（dashboard）

K8S四种核心的附件

CNI网络插件：如果集群足够小，其实不需要网络插件，只需要改iptables规则，增加几条路由就可以了。

在恰当的时候，用恰当的技术，解决恰当的问题。

• CNI网络插件

  
  
  
  
  • flannel（在100台机器的规模内）
  
  
  • 三种常用工作模式
    
    
    
    • NAT
    
    
    • VxLAN
    
    
    
    
  
  
  • 优化SNAT规则（集群内容器通信，能获取到具体的容器IP，而不是宿主机IP）
  
  
  
  



• K8S的服务发现

  
  
  
  
  • 集群网络：clusterIP
  
  
  • Service资源：Service Name
  
  
  • CoreDNS软件：实现了Service Name和Cluster IP的自动关联
  
  
  
  



• K8S的服务暴露

  
  
  
  
  • Ingress资源：专用于暴露7层应用到K8S集群外的一种核心资源（http/https）
  
  
  • ingress controller：一个简化版的nginx（调度流量）+go脚本（动态识别yaml）
  
  
  • Traefik软件：实现了ingress控制器的一个软件
  
  
  
  



• GUI图形化管理插件

  
  

开始安装dashboard

在运维主机上hdss7-200

[root@hdss7-200 k8s-yaml]# docker pull k8scn/kubernetes-dashboard-amd64:v1.8.3
[root@hdss7-200 k8s-yaml]# docker images | grep dashboard
k8scn/kubernetes-dashboard-amd64 v1.8.3 fcac9aa03fd6 2 years ago 102MB
[root@hdss7-200 k8s-yaml]# docker tag fcac9aa03fd6 harbor.od.com/public/dashboard.od.com:v1.8.3
[root@hdss7-200 k8s-yaml]# docker push !$


rbac.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
labels:
k8s-app: kubernetes-dashboard
addonmanager.kubernetes.io/mode: Reconcile
name: kubernetes-dashboard-admin
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: kubernetes-dashboard-admin
namespace: kube-system
labels:
k8s-app: kubernetes-dashboard
addonmanager.kubernetes.io/mode: Reconcile
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: cluster-admin
subjects:
- kind: ServiceAccount
name: kubernetes-dashboard-admin
namespace: kube-system


dp.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
name: kubernetes-dashboard
namespace: kube-system
labels:
k8s-app: kubernetes-dashboard
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
spec:
selector:
matchLabels:
k8s-app: kubernetes-dashboard
template:
metadata:
labels:
k8s-app: kubernetes-dashboard
annotations:
scheduler.alpha.kubernetes.io/critical-pod: ''
spec:
priorityClassName: system-cluster-critical
containers:
- name: kubernetes-dashboard
image: harbor.od.com/public/dashboard:v1.8.3
resources:
limits:
cpu: 100m
memory: 300Mi
requests:
cpu: 50m
memory: 100Mi
ports:
- containerPort: 8443
protocol: TCP
args:
# PLATFORM-SPECIFIC ARGS HERE
- --auto-generate-certificates
volumeMounts:
- name: tmp-volume
mountPath: /tmp
livenessProbe:
httpGet:
scheme: HTTPS
path: /
port: 8443
initialDelaySeconds: 30
timeoutSeconds: 30
volumes:
- name: tmp-volume
emptyDir: {}
serviceAccountName: kubernetes-dashboard-admin
tolerations:
- key: "CriticalAddonsOnly"
operator: "Exists"


- --auto-generate-certificates
# 自动生成证书
livenessProbe:
# 容器存活性探针
# 容器就绪性探针
# 目标是判定容器在K8S容器编排环境下是否正常启动，或者运行的过程中是否有异常退出
# 就绪性探针
# 容器被拉起来之后，先用就绪性探针去探测它，直到它满足我的要求，我认定它为就绪状态，就是running状态
port: 8443
# 监听8443是否存在，存在则说明容器是正常状态


svc.yaml

apiVersion: v1
kind: Service
metadata:
name: kubernetes-dashboard
namespace: kube-system
labels:
k8s-app: kubernetes-dashboard
kubernetes.io/cluster-service: "true"
addonmanager.kubernetes.io/mode: Reconcile
spec:
selector:
k8s-app: kubernetes-dashboard
ports:
- port: 443
targetPort: 8443


ingress.yaml

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: kubernetes-dashboard
namespace: kube-system
annotations:
kubernetes.io/ingress.class: traefik
spec:
rules:
- host: dashboard.od.com
http:
paths:
- backend:
serviceName: kubernetes-dashboard
servicePort: 443


创建资源

[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/rbac.yaml
serviceaccount/kubernetes-dashboard-admin created
clusterrolebinding.rbac.authorization.k8s.io/kubernetes-dashboard-admin created
[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/dp.yaml
deployment.apps/kubernetes-dashboard created
[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/svc.yaml
service/kubernetes-dashboard created
[root@hdss7-22 ~]# kubectl apply -f http://k8s-yaml.od.com/dashboard/ingress.yaml
ingress.extensions/kubernetes-dashboard created


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