[hide]
检查探针---就绪检测
readinessProbe-httpget
创建资源清单
[root@k8s-master ~]# vim read.yaml
apiVersion: v1
kind: Pod
metadata:
name: readiness-httpget-pod
namespace: default
spec:
containers:
- name: readiness-httpget-container
image: nginx:1.17
imagePullPolicy: IfNotPresent
readinessProbe:
httpGet:
port: 80
path: /yz.html
initialDelaySeconds: 1
periodSeconds: 3创建Pod
[root@k8s-master ~]# kubectl create -f read.yaml
pod/readiness-httpget-pod created查看Pod，虽然显示运行状态，但是准备未就绪
[root@k8s-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-pod 2/2 Running 0 2d20h
mysql-rc-jjsmp 1/1 Running 2 50d
mysql-rc-lc22m 1/1 Running 2 55d
mysql-rc-nkdrh 1/1 Running 2 50d
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d13h
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d13h
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d13h
readiness-httpget-pod 0/1 Running 0 5s
yzapp-pod 1/1 Running 19 19h查看Pod的描述信息
[root@k8s-master ~]# kubectl describe pods readiness-httpget-pod
Name: readiness-httpget-pod
Namespace: default
Priority: 0
Node: k8s-node2/42.51.227.115
Start Time: Tue, 24 Nov 2020 03:32:54 +0000
Labels: <none>
Annotations: <none>
Status: Running
IP: 10.244.3.83
IPs:
IP: 10.244.3.83
Containers:
readiness-httpget-container:
Container ID: docker://55adb8df8776d8a6d3a16db8467dde734148a961a5e5ae0ccdf4191fb4109e79
Image: nginx:1.17
Image ID: docker-pullable://nginx@sha256:6fff55753e3b34e36e24e37039ee9eae1fe38a6420d8ae16ef37c92d1eb26699
Port: <none>
Host Port: <none>
State: Running
Started: Tue, 24 Nov 2020 03:32:57 +0000
Ready: False
Restart Count: 0
Readiness: http-get http://:80/yz.html delay=1s timeout=1s period=3s #success=1 #failure=3
Environment: <none>
Mounts:
/var/run/secrets/kubernetes.io/serviceaccount from default-token-hvlcv (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
default-token-hvlcv:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-hvlcv
Optional: false
QoS Class: BestEffort
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled <unknown> default-scheduler Successfully assigned default/readiness-httpget-pod to k8s-node2
Normal Pulled 37s kubelet, k8s-node2 Container image "nginx:1.17" already present on machine
Normal Created 37s kubelet, k8s-node2 Created container readiness-httpget-container
Normal Started 37s kubelet, k8s-node2 Started container readiness-httpget-container
Warning Unhealthy 1s (x12 over 34s) kubelet, k8s-node2 Readiness probe failed: HTTP probe failed with statuscode: 404进入到Pod里的容器，创建yz.html文件
[root@k8s-master ~]# kubectl exec readiness-httpget-pod -it -- /bin/sh
# cd /usr/share/nginx/html
# ls
# 50x.html index.html
# echo "I am YuanZhang" > yz.html
# exit再次查看Pod，显示已经准备就绪了
[root@k8s-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
myapp-pod 2/2 Running 0 2d20h
mysql-rc-jjsmp 1/1 Running 2 50d
mysql-rc-lc22m 1/1 Running 2 55d
mysql-rc-nkdrh 1/1 Running 2 50d
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d13h
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d13h
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d13h
readiness-httpget-pod 1/1 Running 0 2m36s
yzapp-pod 1/1 Running 19 19h检查探针---三种存活检测
livenessProbe-exec
创建资源清单
[root@k8s-master ~]# vim live-exec.yaml
apiVersion: v1
kind: Pod
metadata:
namespace: default
name: liveness-exec-pod
spec:
containers:
- name: liveness-exec-container
image: busybox
imagePullPolicy: IfNotPresent
command: ["/bin/sh","-c","touch /tmp/live; sleep 60; rm -rf /tmp/live; sleep 3600"]
livenessProbe:
exec:
command: ["test","-e","/tmp/live"]
initialDelaySeconds: 1
periodSeconds: 3创建资源
[root@k8s-master ~]# kubectl create -f live-exec.yaml
pod/liveness-exec-pod created查看Pod信息，已经是在运行中了
[root@k8s-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-exec-pod 1/1 Running 0 4s
myapp-pod 2/2 Running 0 3d
mysql-rc-jjsmp 1/1 Running 2 51d
mysql-rc-lc22m 1/1 Running 2 55d
mysql-rc-nkdrh 1/1 Running 2 51d
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d17h
readiness-httpget-pod 1/1 Running 0 3h33m
yzapp-pod 0/1 Completed 22 23h我们持续查看Pod的运行状态
我们发现Pod会重启，因为我们上面的清单里写的命令
command: ["/bin/sh","-c","touch /tmp/live; sleep 60; rm -rf /tmp/live; sleep 3600"]
livenessProbe:
exec:
command: ["test","-e","/tmp/live"]
initialDelaySeconds: 1
periodSeconds: 3
意思就是容器创建后会创建一个文件 /tmp/live，然后休眠60秒，然后删除这个文件，然后再休眠6分钟
在创建容器后的一分钟内文件是存在的，然后一分钟后文件删除了，我们检测不到了这个文件，那么该容器就被杀死了，因为Pod里只有一个容器，那么容器死掉意味着Pod也会被重启，继续执行这个流程，会一直重启。[root@k8s-master ~]# kubectl get pods -w
NAME READY STATUS RESTARTS AGE
liveness-exec-pod 1/1 Running 0 12s
myapp-pod 2/2 Running 0 3d
mysql-rc-jjsmp 1/1 Running 2 51d
mysql-rc-lc22m 1/1 Running 2 55d
mysql-rc-nkdrh 1/1 Running 2 51d
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d17h
readiness-httpget-pod 1/1 Running 0 3h33m
yzapp-pod 1/1 Running 23 23h
livenes-exec-pod 1/1 Running 1 99s
livenes-exec-pod 1/1 Running 2 3m19slivenessProbe-httpget
创建资源清单
[root@k8s-master ~]# vim live-http.yaml
apiVersion: v1
kind: Pod
metadata:
name: liveness-httpget-pod
namespace: default
spec:
containers:
- name: liveness-httpget-container
image: nginx:1.17
imagePullPolicy: IfNotPresent
ports:
- containerPort: 80
name: http
livenessProbe:
httpGet:
port: http
path: /index.html
initialDelaySeconds: 1
periodSeconds: 3创建Pod资源
[root@k8s-master ~]# kubectl create -f live-http.yaml
pod/liveness-httpget-pod created查看Pod信息，显示已经正在运行
[root@k8s-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-exec-pod 0/1 CrashLoopBackOff 11 33m
liveness-httpget-pod 1/1 Running 0 4s
myapp-pod 2/2 Running 0 3d
mysql-rc-jjsmp 1/1 Running 2 51d
mysql-rc-lc22m 1/1 Running 2 55d
mysql-rc-nkdrh 1/1 Running 2 51d
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d17h
readiness-httpget-pod 1/1 Running 0 4h6m
yzapp-pod 1/1 Running 23 23h查看default命名空间下的Pod的详细信息，可以看到我们创建Pod的IP为：10.244.3.84
[root@k8s-master ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
liveness-exec-pod 0/1 CrashLoopBackOff 11 33m 10.244.2.111 k8s-node3 <none> <none>
liveness-httpget-pod 1/1 Running 0 15s 10.244.3.84 k8s-node2 <none> <none>
myapp-pod 2/2 Running 0 3d 10.244.3.82 k8s-node2 <none> <none>
mysql-rc-jjsmp 1/1 Running 2 51d 10.244.1.72 k8s-node1 <none> <none>
mysql-rc-lc22m 1/1 Running 2 55d 10.244.2.80 k8s-node3 <none> <none>
mysql-rc-nkdrh 1/1 Running 2 51d 10.244.3.65 k8s-node2 <none> <none>
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d17h 10.244.2.98 k8s-node3 <none> <none>
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d17h 10.244.2.100 k8s-node3 <none> <none>
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d17h 10.244.3.73 k8s-node2 <none> <none>
readiness-httpget-pod 1/1 Running 0 4h6m 10.244.3.83 k8s-node2 <none> <none>
yzapp-pod 1/1 Running 23 23h 10.244.2.110 k8s-node3 <none> <none>我们访问Pod的nginx，可以看到访问正常
[root@k8s-master ~]# curl 10.244.3.84/index.html
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
body {
width: 35em;
margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif;
}
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>删除Pod的容器里的usr/share/nginx/html/index.html文件
[root@k8s-master ~]# kubectl exec liveness-httpget-pod -it -- rm -rf /usr/share/nginx/html/index.html删除后查看Pod信息，发现Pod已经被重启了
[root@k8s-master ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
liveness-exec-pod 0/1 CrashLoopBackOff 15 51m
liveness-httpget-pod 1/1 Running 1 17m
myapp-pod 2/2 Running 0 3d1h
mysql-rc-jjsmp 1/1 Running 2 51d
mysql-rc-lc22m 1/1 Running 2 55d
mysql-rc-nkdrh 1/1 Running 2 51d
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d17h
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d17h
readiness-httpget-pod 1/1 Running 0 4h24m
yzapp-pod 1/1 Running 23 24hlivenessProbe-tcp
创建资源清单
为了方便测试效果，我们这里把80端口写成8080，这样可以直接看到实验效果
[root@k8s-master ~]# vim liveness-tcp.yaml
apiVersion: v1
kind: Pod
metadata:
name: liveness-tcp-pod
namespace: default
spec:
containers:
- name: liveness-tcp-container
image: nginx:1.17
imagePullPolicy: IfNotPresent
livenessProbe:
initialDelaySeconds: 5
timeoutSeconds: 1
tcpSocket:
port: 8080
periodSeconds: 35秒以后开始检测，检测时候发起连接我们的8080端口，但是端口肯定是不通的，然后一秒以后自己知道是失败了，然后重启Pod
创建Pod资源
[root@k8s-master ~]# kubectl create -f liveness-tcp.yaml
pod/liveness-tcp-pod created持续查看Pod信息，发现已经被重启
[root@k8s-master ~]# kubectl get pods -w
NAME READY STATUS RESTARTS AGE
livenes-exec-pod 0/1 CrashLoopBackOff 19 68m
liveness-httpget-pod 1/1 Running 1 35m
liveness-tcp-pod 1/1 Running 0 8s
myapp-pod 2/2 Running 0 3d1h
mysql-rc-jjsmp 1/1 Running 2 51d
mysql-rc-lc22m 1/1 Running 2 55d
mysql-rc-nkdrh 1/1 Running 2 51d
nginx-app-756ffb5cc8-52hdh 1/1 Running 0 7d18h
nginx-app-756ffb5cc8-bgcbh 1/1 Running 0 7d18h
nginx-app-756ffb5cc8-smztw 1/1 Running 0 7d18h
readiness-httpget-pod 1/1 Running 0 4h41m
yzapp-pod 1/1 Running 24 24h
liveness-tcp-pod 1/1 Running 1 13s
liveness-tcp-pod 1/1 Running 2 26s[/hide]
heian黑暗
qq群来的。帮顶
科技三
大哥牛逼
看看