飞天使-k8s知识点17-kubernetes实操2-pod探针的使用

探针的使用

kubectl edit deploy -n kube-system corednslivenessprobe 的使用 livenessProbe:failureThreshold: 5httpGet:path: /healthport: 8080scheme: HTTPinitialDelaySeconds: 60periodSeconds: 10successThreshold: 1timeoutSeconds: 5readinessProbereadinessProbe:failureThreshold: 3httpGet:path: /readyport: 8181scheme: HTTPperiodSeconds: 10successThreshold: 1timeoutSeconds: 1kubectl edit po nginx kubectl describe po nginx-daemon
最下面有容器启动时候相关日志

容器探针启动实验1-启动探针的使用-startupprobe

Events:Type     Reason     Age               From               Message----     ------     ----              ----               -------Normal   Scheduled  20s               default-scheduler  Successfully assigned default/my-pod1 to ha2.example.localNormal   Pulled     20s               kubelet            Container image "nginx:1.7.9" already present on machineNormal   Created    20s               kubelet            Created container nginxNormal   Started    20s               kubelet            Started container nginxWarning  Unhealthy  4s (x2 over 14s)  kubelet            Startup probe failed: HTTP probe failed with statuscode: 404
[root@kubeadm-master1 test]# kubectl get pod
NAME                                 READY   STATUS    RESTARTS   AGE
client                               1/1     Running   0          48d
my-pod                               1/1     Running   0          7d23h
my-pod1                              0/1     Running   0          37s
net-test1                            1/1     Running   133        55d
net-test2                            1/1     Running   13         55d
nginx-deployment-67dfd6c8f9-5s6nz    1/1     Running   1          55d
tomcat-deployment-6c44f58b47-4pz6d   1/1     Running   1          55d
[root@kubeadm-master1 test]# kubectl get pod
NAME                                 READY   STATUS    RESTARTS   AGE
client                               1/1     Running   0          48d
my-pod                               1/1     Running   0          7d23h
my-pod1                              0/1     Running   0          42s
net-test1                            1/1     Running   133        55d
net-test2                            1/1     Running   13         55d
nginx-deployment-67dfd6c8f9-5s6nz    1/1     Running   1          55d
tomcat-deployment-6c44f58b47-4pz6d   1/1     Running   1          55d
[root@kubeadm-master1 test]# cat nginx-po.yaml
apiVersion: v1
kind: Pod
metadata:name: my-pod1labels:type: apptest: "1.0.0"namespace: default
spec:containers:- name: nginximage: nginx:1.7.9imagePullPolicy: IfNotPresentcommand:- nginx- -g- 'daemon off;'workingDir: /usr/share/nginx/htmlports:- name: httpcontainerPort: 80protocol: TCPenv:- name: JVM_OPTSvalue: '-Xms128m -Xmx128m'resources:requests:cpu: 100mmemory: 128Milimits:cpu: 200mmemory: 256MistartupProbe:httpGet:path: /api/pathport: 80failureThreshold: 3periodSeconds: 10successThreshold: 1timeoutSeconds: 5restartPolicy: OnFailure

Liveness Probes 和 Readiness Probes

用于检查容器是否还在运行。如果 liveness 探针失败，Kubernetes 将杀死容器，并根据其重启策略来处理。
用于检查容器是否已经准备好接收流量。如果 readiness 探针失败，Kubernetes 将不会将流量路由到该容器。定义了一个 startupProbe，它在容器启动后通过 HTTP GET 请求检查 /api/path 端点。现在我们将添加 livenessProbe 和 readinessProbe。一个 livenessProbe 可以如下定义：livenessProbe:httpGet:path: /api/healthport: 80initialDelaySeconds: 30periodSeconds: 10
这个 livenessProbe 会在容器启动后的30秒开始工作，每10秒检查一次 /api/health 端点。一个 readinessProbe 可以如下定义：readinessProbe:httpGet:path: /api/readyport: 80initialDelaySeconds: 5periodSeconds: 5
这个 readinessProbe 会在容器启动后的5秒开始工作，每5秒检查一次 /api/ready 端点。

演示

[root@kubeadm-master1 test]# cat liveness.yml
apiVersion: v1
kind: Pod
metadata:name: my-pod1labels:type: apptest: "1.0.0"namespace: default
spec:containers:- name: nginximage: nginx:1.7.9imagePullPolicy: IfNotPresentcommand:- nginx- -g- 'daemon off;'workingDir: /usr/share/nginx/htmlports:- name: httpcontainerPort: 80protocol: TCPenv:- name: JVM_OPTSvalue: '-Xms128m -Xmx128m'resources:requests:cpu: 100mmemory: 128Milimits:cpu: 200mmemory: 256MistartupProbe:httpGet:path: /api/pathport: 80failureThreshold: 3periodSeconds: 10successThreshold: 1timeoutSeconds: 5livenessProbe:httpGet:path: /api/healthport: 80initialDelaySeconds: 30periodSeconds: 10readinessProbe:httpGet:path: /api/readyport: 80initialDelaySeconds: 5periodSeconds: 5restartPolicy: OnFailureState:          RunningStarted:      Thu, 15 Feb 2024 15:15:19 +0800Ready:          FalseRestart Count:  0Limits:cpu:     200mmemory:  256MiRequests:cpu:      100mmemory:   128MiLiveness:   http-get http://:80/api/health delay=30s timeout=1s period=10s #success=1 #failure=3Readiness:  http-get http://:80/api/ready delay=5s timeout=1s period=5s #success=1 #failure=3Startup:    http-get http://:80/api/path delay=0s timeout=5s period=10s #success=1 #failure=3Environment:JVM_OPTS:  -Xms128m -Xmx128mMounts:/var/run/secrets/kubernetes.io/serviceaccount from default-token-75cq9 (ro)
Conditions:Type              StatusInitialized       TrueReady             FalseContainersReady   FalsePodScheduled      True
Volumes:default-token-75cq9:Type:        Secret (a volume populated by a Secret)SecretName:  default-token-75cq9Optional:    false
QoS Class:       Burstable
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute op=Exists for 300snode.kubernetes.io/unreachable:NoExecute op=Exists for 300s
Events:Type     Reason     Age               From               Message----     ------     ----              ----               -------Normal   Scheduled  19s               default-scheduler  Successfully assigned default/my-pod1 to ha2.example.localNormal   Pulled     19s               kubelet            Container image "nginx:1.7.9" already present on machineNormal   Created    19s               kubelet            Created container nginxNormal   Started    19s               kubelet            Started container nginxWarning  Unhealthy  2s (x2 over 12s)  kubelet            Startup probe failed: HTTP probe failed with statuscode: 404

若存在started.html 则进行