网站建设到运营赚钱,网站开发计算机配置,用dw做教学网站,自己做网站选什么好在《研发工程师玩转Kubernetes——启动、存活和就绪探针》中#xff0c;我们讲了就绪探针和服务之间的特殊关系。就绪探针检测失败并不代表整个程序处于“非存活”状态#xff0c;可能只是短暂临时的不可以提供服务#xff0c;比如CPU阶段性占满#xff0c;导致就绪探针检测…在《研发工程师玩转Kubernetes——启动、存活和就绪探针》中我们讲了就绪探针和服务之间的特殊关系。就绪探针检测失败并不代表整个程序处于“非存活”状态可能只是短暂临时的不可以提供服务比如CPU阶段性占满导致就绪探针检测超时而导致失败。这个时候就绪探针并不会向存活探针那样尝试重启容器而只是简单的把它从何它关联的Service中摘除。
带Readiness Probe的Nginx
apiVersion: apps/v1
kind: Deployment
metadata:name: readiness-nginx-deployment
spec:selector:matchLabels:app: readiness-nginxreplicas: 2template:metadata:labels:app: readiness-nginxspec:containers:- name: readiness-nginx-containerimage: nginxports:- containerPort: 80command: [/bin/sh, -c, sleep 3; touch /tempdir/readiness-nginx; while true; do sleep 5; done]volumeMounts:- name: probe-volumemountPath: /tempdirreadinessProbe:exec:command:- cat- /tempdir/readiness-nginxinitialDelaySeconds: 2failureThreshold: 6periodSeconds: 1successThreshold: 1volumes:- name: probe-volumeemptyDir: medium: MemorysizeLimit: 1GiNginx关联的Service
kind: Service
apiVersion: v1
metadata:name: readiness-nginx-service
spec:selector:app: readiness-nginxports:- protocol: TCPport: 80targetPort: 80实验
创建上述组件可以看到启动了下面的Pod
kubectl get pod -o wideNAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
readiness-nginx-deployment-57b7fd5644-7x7wc 1/1 Running 0 25s 10.1.43.223 ubuntuc none none
readiness-nginx-deployment-57b7fd5644-lhszp 1/1 Running 0 25s 10.1.209.155 ubuntub none noneService也绑定了这些IP。
kubectl describe endpoints readiness-nginx-service Name: readiness-nginx-service
Namespace: default
Labels: none
Annotations: endpoints.kubernetes.io/last-change-trigger-time: 2023-08-14T14:35:33Z
Subsets:Addresses: 10.1.209.155,10.1.43.223NotReadyAddresses: nonePorts:Name Port Protocol---- ---- --------unset 80 TCPEvents: none现在我们挑选一个容器readiness-nginx-deployment-57b7fd5644-7x7wc10.1.43.223观察该容器的Event状态
kubectl describe pod readiness-nginx-deployment-57b7fd5644-7x7wcName: readiness-nginx-deployment-57b7fd5644-7x7wc
Namespace: default
Priority: 0
Service Account: default
Node: ubuntuc/172.22.247.176
Start Time: Mon, 14 Aug 2023 14:35:27 0000
Labels: appreadiness-nginxpod-template-hash57b7fd5644
Annotations: cni.projectcalico.org/containerID: c475d3e82ff0d5adbd35252ab990608ad75955f8d0862bb8b0c54ee60a0878ebcni.projectcalico.org/podIP: 10.1.43.223/32cni.projectcalico.org/podIPs: 10.1.43.223/32
Status: Running
IP: 10.1.43.223
IPs:IP: 10.1.43.223
Controlled By: ReplicaSet/readiness-nginx-deployment-57b7fd5644
Containers:readiness-nginx-container:Container ID: containerd://5d82d8467bc6e0c8151e40ee3258d54bffec8659bcdad4a441848ea8f77a3223Image: nginxImage ID: docker.io/library/nginxsha256:67f9a4f10d147a6e04629340e6493c9703300ca23a2f7f3aa56fe615d75d31caPort: 80/TCPHost Port: 0/TCPCommand:/bin/sh-csleep 3; touch /tempdir/readiness-nginx; while true; do sleep 5; doneState: RunningStarted: Mon, 14 Aug 2023 14:35:30 0000Ready: TrueRestart Count: 0Readiness: exec [cat /tempdir/readiness-nginx] delay2s timeout1s period1s #success1 #failure6Environment: noneMounts:/tempdir from probe-volume (rw)/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-c4tcl (ro)
Conditions:Type StatusInitialized True Ready True ContainersReady True PodScheduled True
Volumes:probe-volume:Type: EmptyDir (a temporary directory that shares a pods lifetime)Medium: MemorySizeLimit: 1Gikube-api-access-c4tcl:Type: Projected (a volume that contains injected data from multiple sources)TokenExpirationSeconds: 3607ConfigMapName: kube-root-ca.crtConfigMapOptional: nilDownwardAPI: true
QoS Class: BestEffort
Node-Selectors: none
Tolerations: node.kubernetes.io/not-ready:NoExecute opExists for 300snode.kubernetes.io/unreachable:NoExecute opExists for 300s
Events:Type Reason Age From Message---- ------ ---- ---- -------Normal Scheduled 3m53s default-scheduler Successfully assigned default/readiness-nginx-deployment-57b7fd5644-7x7wc to ubuntucNormal Pulling 3m53s kubelet Pulling image nginxNormal Pulled 3m50s kubelet Successfully pulled image nginx in 2.489885583s (2.489893984s including waiting)Normal Created 3m50s kubelet Created container readiness-nginx-containerNormal Started 3m50s kubelet Started container readiness-nginx-containerWarning Unhealthy 3m48s (x2 over 3m48s) kubelet Readiness probe failed: cat: /tempdir/readiness-nginx: No such file or directory可以看到就绪探针在第3次检测时就存在了这个时候Pod的Ready和ContainersReady都是True的状态。
就绪-非就绪
现在我们删除就绪标志文件
kubectl exec pods/readiness-nginx-deployment-57b7fd5644-7x7wc --container readiness-nginx-container -- rm /tempdir/readiness-nginx再观察其状态可以发现
Name: readiness-nginx-deployment-57b7fd5644-7x7wc
Namespace: default
Priority: 0
Service Account: default
Node: ubuntuc/172.22.247.176
Start Time: Mon, 14 Aug 2023 14:35:27 0000
Labels: appreadiness-nginxpod-template-hash57b7fd5644
Annotations: cni.projectcalico.org/containerID: c475d3e82ff0d5adbd35252ab990608ad75955f8d0862bb8b0c54ee60a0878ebcni.projectcalico.org/podIP: 10.1.43.223/32cni.projectcalico.org/podIPs: 10.1.43.223/32
Status: Running
IP: 10.1.43.223
IPs:IP: 10.1.43.223
Controlled By: ReplicaSet/readiness-nginx-deployment-57b7fd5644
Containers:readiness-nginx-container:Container ID: containerd://5d82d8467bc6e0c8151e40ee3258d54bffec8659bcdad4a441848ea8f77a3223Image: nginxImage ID: docker.io/library/nginxsha256:67f9a4f10d147a6e04629340e6493c9703300ca23a2f7f3aa56fe615d75d31caPort: 80/TCPHost Port: 0/TCPCommand:/bin/sh-csleep 3; touch /tempdir/readiness-nginx; while true; do sleep 5; doneState: RunningStarted: Mon, 14 Aug 2023 14:35:30 0000Ready: FalseRestart Count: 0Readiness: exec [cat /tempdir/readiness-nginx] delay2s timeout1s period1s #success1 #failure6Environment: noneMounts:/tempdir from probe-volume (rw)/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-c4tcl (ro)
Conditions:Type StatusInitialized True Ready False ContainersReady False PodScheduled True
Volumes:probe-volume:Type: EmptyDir (a temporary directory that shares a pods lifetime)Medium: MemorySizeLimit: 1Gikube-api-access-c4tcl:Type: Projected (a volume that contains injected data from multiple sources)TokenExpirationSeconds: 3607ConfigMapName: kube-root-ca.crtConfigMapOptional: nilDownwardAPI: true
QoS Class: BestEffort
Node-Selectors: none
Tolerations: node.kubernetes.io/not-ready:NoExecute opExists for 300snode.kubernetes.io/unreachable:NoExecute opExists for 300s
Events:Type Reason Age From Message---- ------ ---- ---- -------Warning Unhealthy 7s (x22 over 6m6s) kubelet Readiness probe failed: cat: /tempdir/readiness-nginx: No such file or directory可以看到Ready和ContainersReady都变成了False状态。 我们再观察Service
kubectl describe endpoints readiness-nginx-service Name: readiness-nginx-service
Namespace: default
Labels: none
Annotations: endpoints.kubernetes.io/last-change-trigger-time: 2023-08-14T14:41:18Z
Subsets:Addresses: 10.1.209.155NotReadyAddresses: 10.1.43.223Ports:Name Port Protocol---- ---- --------unset 80 TCPEvents: none可以看到被删除了就绪探针检测文件的Pod被从Service中摘掉了。
非就绪-就绪
我们再将检测文件还原
kubectl exec pods/readiness-nginx-deployment-57b7fd5644-7x7wc --container readiness-nginx-container -- touch /tempdir/readiness-nginx观察对应Pod的状态其Ready和ContainersReady又变成了True状态。
Name: readiness-nginx-deployment-57b7fd5644-7x7wc
Namespace: default
Priority: 0
Service Account: default
Node: ubuntuc/172.22.247.176
Start Time: Mon, 14 Aug 2023 14:35:27 0000
Labels: appreadiness-nginxpod-template-hash57b7fd5644
Annotations: cni.projectcalico.org/containerID: c475d3e82ff0d5adbd35252ab990608ad75955f8d0862bb8b0c54ee60a0878ebcni.projectcalico.org/podIP: 10.1.43.223/32cni.projectcalico.org/podIPs: 10.1.43.223/32
Status: Running
IP: 10.1.43.223
IPs:IP: 10.1.43.223
Controlled By: ReplicaSet/readiness-nginx-deployment-57b7fd5644
Containers:readiness-nginx-container:Container ID: containerd://5d82d8467bc6e0c8151e40ee3258d54bffec8659bcdad4a441848ea8f77a3223Image: nginxImage ID: docker.io/library/nginxsha256:67f9a4f10d147a6e04629340e6493c9703300ca23a2f7f3aa56fe615d75d31caPort: 80/TCPHost Port: 0/TCPCommand:/bin/sh-csleep 3; touch /tempdir/readiness-nginx; while true; do sleep 5; doneState: RunningStarted: Mon, 14 Aug 2023 14:35:30 0000Ready: TrueRestart Count: 0Readiness: exec [cat /tempdir/readiness-nginx] delay2s timeout1s period1s #success1 #failure6Environment: noneMounts:/tempdir from probe-volume (rw)/var/run/secrets/kubernetes.io/serviceaccount from kube-api-access-c4tcl (ro)
Conditions:Type StatusInitialized True Ready True ContainersReady True PodScheduled True
Volumes:probe-volume:Type: EmptyDir (a temporary directory that shares a pods lifetime)Medium: MemorySizeLimit: 1Gikube-api-access-c4tcl:Type: Projected (a volume that contains injected data from multiple sources)TokenExpirationSeconds: 3607ConfigMapName: kube-root-ca.crtConfigMapOptional: nilDownwardAPI: true
QoS Class: BestEffort
Node-Selectors: none
Tolerations: node.kubernetes.io/not-ready:NoExecute opExists for 300snode.kubernetes.io/unreachable:NoExecute opExists for 300s
Events:Type Reason Age From Message---- ------ ---- ---- -------Warning Unhealthy 3m5s (x262 over 13m) kubelet Readiness probe failed: cat: /tempdir/readiness-nginx: No such file or directoryService也重新将其加回来了。
Name: readiness-nginx-service
Namespace: default
Labels: none
Annotations: endpoints.kubernetes.io/last-change-trigger-time: 2023-08-14T14:48:23Z
Subsets:Addresses: 10.1.209.155,10.1.43.223NotReadyAddresses: nonePorts:Name Port Protocol---- ---- --------unset 80 TCPEvents: none
