K8S动态伸缩和失效转移
大约 3 分钟约 986 字
K8S动态伸缩和失效转移
扩容和缩容
第一方式
kubectl scale deployment nginx-deploy --replicas=8
//使用命令行的方式进行扩容操作(缩容也是一样的道理)
kubectl get pod -o wide | grep nginx | wc -l
8
kubectl get deployments. nginx-deploy -o yaml
kubectl get deployments. nginx-deploy -o json
//也可以将nginx资源类型已json或yaml文件格式输出(其中也可查看到副本的数量)
第二种方式
[root@master v3]# kubectl edit deployments nginx-deploy
//编辑名为nginx的资源类型
19 spec: //找到spec字段
20 progressDeadlineSeconds: 600
21 replicas: 6 //更改副本数量
//在保存退出的一瞬间就生效了
[root@master v3]# kubectl get pod -o wide | grep nginx | wc -l
6
//查看副本数量
弹性伸缩
部署部署metrics-server
apiVersion: v1
kind: ServiceAccount
metadata:
labels:
k8s-app: metrics-server
name: metrics-server
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
k8s-app: metrics-server
rbac.authorization.k8s.io/aggregate-to-admin: "true"
rbac.authorization.k8s.io/aggregate-to-edit: "true"
rbac.authorization.k8s.io/aggregate-to-view: "true"
name: system:aggregated-metrics-reader
rules:
- apiGroups:
- metrics.k8s.io
resources:
- pods
- nodes
verbs:
- get
- list
- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
labels:
k8s-app: metrics-server
name: system:metrics-server
rules:
- apiGroups:
- ""
resources:
- pods
- nodes
- nodes/stats
- namespaces
- configmaps
verbs:
- get
- list
- watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
labels:
k8s-app: metrics-server
name: metrics-server-auth-reader
namespace: kube-system
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: Role
name: extension-apiserver-authentication-reader
subjects:
- kind: ServiceAccount
name: metrics-server
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
k8s-app: metrics-server
name: metrics-server:system:auth-delegator
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:auth-delegator
subjects:
- kind: ServiceAccount
name: metrics-server
namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
labels:
k8s-app: metrics-server
name: system:metrics-server
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: system:metrics-server
subjects:
- kind: ServiceAccount
name: metrics-server
namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
labels:
k8s-app: metrics-server
name: metrics-server
namespace: kube-system
spec:
ports:
- name: https
port: 443
protocol: TCP
targetPort: https
selector:
k8s-app: metrics-server
---
apiVersion: apps/v1
kind: Deployment
metadata:
labels:
k8s-app: metrics-server
name: metrics-server
namespace: kube-system
spec:
selector:
matchLabels:
k8s-app: metrics-server
strategy:
rollingUpdate:
maxUnavailable: 0
template:
metadata:
labels:
k8s-app: metrics-server
spec:
containers:
- args:
- --cert-dir=/tmp
- --secure-port=443
- --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
- --kubelet-use-node-status-port
- --metric-resolution=15s
- --kubelet-insecure-tls
image: registry.aliyuncs.com/k8sxio/metrics-server:v0.5.0
imagePullPolicy: IfNotPresent
livenessProbe:
failureThreshold: 3
httpGet:
path: /livez
port: https
scheme: HTTPS
periodSeconds: 10
name: metrics-server
ports:
- containerPort: 443
name: https
protocol: TCP
readinessProbe:
failureThreshold: 3
httpGet:
path: /readyz
port: https
scheme: HTTPS
initialDelaySeconds: 20
periodSeconds: 10
resources:
requests:
cpu: 100m
memory: 200Mi
securityContext:
readOnlyRootFilesystem: true
runAsNonRoot: true
runAsUser: 1000
volumeMounts:
- mountPath: /tmp
name: tmp-dir
nodeSelector:
kubernetes.io/os: linux
priorityClassName: system-cluster-critical
serviceAccountName: metrics-server
volumes:
- emptyDir: {}
name: tmp-dir
---
apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:
labels:
k8s-app: metrics-server
name: v1beta1.metrics.k8s.io
spec:
group: metrics.k8s.io
groupPriorityMinimum: 100
insecureSkipTLSVerify: true
service:
name: metrics-server
namespace: kube-system
version: v1beta1
versionPriority: 100
编写hpa.yaml配置文件
apiVersion: apps/v1
kind: Deployment
metadata:
name: deployment-hpa-cpu
spec:
replicas: 1
selector:
matchLabels:
app: myapp
template:
metadata:
labels:
app: myapp
spec:
containers:
- name: myapp
image: nginx
ports:
- containerPort: 80
resources:
limits:
cpu: 20m
memory: 10Mi
requests:
cpu: 20m
memory: 10Mi
---
apiVersion: v1
kind: Service
metadata:
name: myapp
spec:
type: ClusterIP
selector:
app: myapp
ports:
- name: http
port: 80
targetPort: 80
---
apiVersion: autoscaling/v1
kind: HorizontalPodAutoscaler
metadata:
name: deployment-hpa-cpu
spec:
maxReplicas: 6
minReplicas: 1
scaleTargetRef:
apiVersion: apps/v1
kind: Deployment
name: deployment-hpa-cpu
targetCPUUtilizationPercentage: 80
部署hpa
kubectl apply -f hpa-cpu.yaml
测试 HPA
# 开三个 k8s-master01 窗口，分别执行下面三条命令
watch kubectl get pods
watch kubectl top pods
ip=$(kubectl get svc | grep myapp | awk '{print $3}')
for i in `seq 1 100000`; do curl $ip?a=$i; done
while true; do wget -q -O- 10.98.114.85; done
失效转移
编写失效转移的文件
apiVersion: apps/v1
kind: Deployment
metadata:
name: my-nginx-deploy
spec:
replicas: 2
selector:
matchLabels:
app: my-nginx
template:
metadata:
labels:
app: my-nginx
spec:
tolerations:
- key: "node.kubernetes.io/unreachable"
operator: "Exists"
effect: "NoExecute"
tolerationSeconds: 2
- key: "node.kubernetes.io/not-ready"
operator: "Exists"
effect: "NoExecute"
tolerationSeconds: 2
containers:
- name: my-nginx-container
image: nginx
ports:
- containerPort: 80
kubernetes节点失效后pod的调度过程：
0、Master每隔一段时间和node联系一次，判定node是否失联，这个时间周期配置项为 node-monitor-period ，默认5s
1、当node失联后一段时间后，kubernetes判定node为notready状态，这段时长的配置项为 node-monitor-grace-period ，默认40s
2、当node失联后一段时间后，kubernetes判定node为unhealthy，这段时长的配置项为 node-startup-grace-period ，默认1m0s
3、当node失联后一段时间后，kubernetes开始删除原node上的pod，这段时长配置项为 pod-eviction-timeout ，默认5m0s
停止掉工作节点看看是否发生转移
systemctl stop kubelet