- 记录一个简单的livenessProb的使用
创建livenessProbe探针
具体的liveness-httpget.yaml文件如下：
apiVersion: v1
kind: Pod
metadata:
name: liveness-httpget-pod
namespace: default
spec:
containers:
- name: liveness-exec-container
image: ikubernetes/myapp:v1
imagePullPolicy: IfNotPresent
ports:
- name: http
containerPort: 80
livenessProbe:
httpGet:
port: http
path: /index.html
initialDelaySeconds: 1
periodSeconds: 3
[root@master manifests]# cat liveness-httpget.yaml
apiVersion: v1
kind: Pod
metadata:
name: liveness-httpget-pod
namespace: default
spec:
containers:
- name: liveness-exec-container
image: ikubernetes/myapp:v1
imagePullPolicy: IfNotPresent
ports:
- name: http
containerPort: 80
livenessProbe:
httpGet:
port: http
path: /index.html
initialDelaySeconds: 1
periodSeconds: 3创建该pod
[root@master manifests]# kubectl create -f liveness-httpget.yaml
pod/liveness-httpget-pod created查看当前pod的状态
[root@master manifests]# kubectl describe pod liveness-httpget-pod
Name: liveness-httpget-pod
Namespace: default
Priority: 0
PriorityClassName:
Node: node02/192.168.18.130
Start Time: Fri, 17 Aug 2018 18:24:26 +0800
Labels:
Annotations:
Status: Running
IP: 10.244.2.40
Containers:
liveness-exec-container:
Container ID: docker://b00bc09eac7c4dcadb482dd9795a9f7e6d9b68ca63e75384da18feb0ef7bdc6d
Image: ikubernetes/myapp:v1
Image ID: docker-pullable://ikubernetes/myapp@sha256:9c3dc30b5219788b2b8a4b065f548b922a34479577befb54b03330999d30d513
Port: 80/TCP
Host Port: 0/TCP
State: Running
Started: Fri, 17 Aug 2018 18:24:27 +0800
Ready: True
Restart Count: 0
Liveness: http-get http://:http/index.html delay=1s timeout=1s period=3s #success=1 #failure=3
Environment:
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-qcfxf (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-qcfxf:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-qcfxf
Optional: false
QoS Class: BestEffort
Node-Selectors:
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Pulled 37s kubelet, node02 Container image "ikubernetes/myapp:v1" already present on machine
Normal Created 37s kubelet, node02 Created container
Normal Started 37s kubelet, node02 Started container
Normal Scheduled 32s default-scheduler Successfully assigned default/liveness-httpget-pod to node02 测试将容器内的index.html删除掉
登陆容器
使用命令 kubectl exec liveness-httpget-pod -c liveness-exec-container -it -- /bin/sh 登陆容器
[root@master manifests]# kubectl exec liveness-httpget-pod -c liveness-exec-container -it -- /bin/sh
/ # ls
bin dev etc home lib media mnt proc root run sbin srv sys tmp usr var
/ # mv /usr/share/nginx/html/index.html index.html
/ # command terminated with exit code 137可以看到，当我们把index.html移走后，这个容器立马就退出了。
此时，查看pod的信息
[root@master manifests]# kubectl describe pod liveness-httpget-pod
Name: liveness-httpget-pod
Namespace: default
Priority: 0
PriorityClassName:
Node: node02/192.168.18.130
Start Time: Fri, 17 Aug 2018 18:24:26 +0800
Labels:
Annotations:
Status: Running
IP: 10.244.2.40
Containers:
liveness-exec-container:
Container ID: docker://ac663b9e29c2cbc9c1d0283f1609914be69964149247945266ddcc8b33dde12f
Image: ikubernetes/myapp:v1
Image ID: docker-pullable://ikubernetes/myapp@sha256:9c3dc30b5219788b2b8a4b065f548b922a34479577befb54b03330999d30d513
Port: 80/TCP
Host Port: 0/TCP
State: Running
Started: Fri, 17 Aug 2018 18:48:07 +0800
Last State: Terminated
Reason: Completed
Exit Code: 0
Started: Fri, 17 Aug 2018 18:24:27 +0800
Finished: Fri, 17 Aug 2018 18:48:06 +0800
Ready: True
Restart Count: 1
Liveness: http-get http://:http/index.html delay=1s timeout=1s period=3s #success=1 #failure=3
Environment:
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-qcfxf (ro)
Conditions:
Type Status
Initialized True
Ready True
ContainersReady True
PodScheduled True
Volumes:
default-token-qcfxf:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-qcfxf
Optional: false
QoS Class: BestEffort
Node-Selectors:
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 24m default-scheduler Successfully assigned default/liveness-httpget-pod to node02
Warning Unhealthy 1m (x3 over 1m) kubelet, node02 Liveness probe failed: HTTP probe failed with statuscode: 404
Normal Pulled 1m (x2 over 24m) kubelet, node02 Container image "ikubernetes/myapp:v1" already present on machine
Normal Created 1m (x2 over 24m) kubelet, node02 Created container
Normal Started 1m (x2 over 24m) kubelet, node02 Started container
Normal Killing 1m kubelet, node02 Killing container with id docker://liveness-exec-container:Container failed liveness probe.. Container will be killed and recreated. 看输出，容器由于健康检查未通过，pod会被杀掉，并重新创建
[root@master manifests]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-httpget-pod 1/1 Running 1 33mrestarts 为 1
重新登陆容器查看
重新登陆容器，发现index.html又出现了，证明容器是被重拉了。
[root@master manifests]# kubectl exec liveness-httpget-pod -c liveness-exec-container -it -- /bin/sh
/ # cat /usr/share/nginx/html/index.html
Hello MyApp | Version: v1 | Pod Name