一、名稱空間
1、切換名稱空間
[root@master pod]# kubectl create ns test
namespace/test created
[root@master pod]# kubectl get ns
NAME STATUS AGE
default Active 10h
kube-node-lease Active 10h
kube-public Active 10h
kube-system Active 10h
test Active 2s
[root@master pod]# kubectl config set-context --current --namespace=kube-system
Context "kubernetes-admin@kubernetes" modified.
[root@master pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
calico-kube-controllers-d886b8fff-mbdz7 1/1 Running 0 6h42m
calico-node-48tnk 1/1 Running 0 6h46m
calico-node-jq7mr 1/1 Running 0 6h46m
calico-node-pdwcr 1/1 Running 0 6h46m
coredns-567c556887-99cqw 1/1 Running 1 (6h44m ago) 10h
coredns-567c556887-9sbfp 1/1 Running 1 (6h44m ago) 10h
etcd-master 1/1 Running 1 (6h44m ago) 10h
kube-apiserver-master 1/1 Running 1 (6h44m ago) 10h
kube-controller-manager-master 1/1 Running 1 (6h44m ago) 10h
kube-proxy-7dl5r 1/1 Running 1 (6h50m ago) 10h
kube-proxy-pvbrg 1/1 Running 1 (6h44m ago) 10h
kube-proxy-xsqt9 1/1 Running 1 (6h50m ago) 10h
kube-scheduler-master 1/1 Running 1 (6h44m ago) 10h
[root@master pod]# kubectl config set-context --current --namespace=default
Context "kubernetes-admin@kubernetes" modified.
[root@master pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx1 1/1 Running 0 8m44s
2、設定名稱空間資源限額
-
就是不能超過這個名稱空間的限制
-
限制這個名稱空間所有pod的型別的限制
[root@master ns]# cat test.yaml
apiVersion: v1
kind: ResourceQuota #這個是資源配額
metadata:
name: mem-cpu-qutoa
namespace: test
spec:
hard: #限制資源
requests.cpu: "2" #最少2個cpu
requests.memory: 2Gi
limits.cpu: "4" #最大4個cpu
limits.memory: 4Gi
#檢視名稱空間詳細資訊
[root@master ns]# kubectl describe ns test
Name: test
Labels: kubernetes.io/metadata.name=test
Annotations: <none>
Status: Active
Resource Quotas
Name: mem-cpu-qutoa
Resource Used Hard
-------- --- ---
limits.cpu 0 4
limits.memory 0 4Gi
requests.cpu 0 2
requests.memory 0 2Gi
No LimitRange resource.
#定義了名稱空間限制的話，建立Pod必須設定資源限制，否則會報錯
[root@master pod]# cat nginx.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx1
namespace: test
labels:
app: nginx-pod
spec:
containers:
- name: nginx01
image: docker.io/library/nginx:1.9.1
imagePullPolicy: IfNotPresent
resources: #pod資源的限制，如果不做限制的話,pod出現了問題的話，一直吃記憶體的話，就會出現問題
limits:
memory: "2Gi" #記憶體為2g
cpu: "2m" #單位為毫核，1000m=1核
二、標籤
-
這個非常的重要，因為很多的資源型別都是靠這個標籤進行管理的(識別到了)
-
服務或者控制器等都是靠這個標籤來進行管理的
#打上標籤
[root@master /]# kubectl label pods nginx1 test=01
pod/nginx1 labeled
[root@master /]# kubectl get pod --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx1 1/1 Running 0 45m app=nginx-pod,test=01
#具有這個標籤的pod進行列出
[root@master /]# kubectl get pods -l app=nginx-pod
NAME READY STATUS RESTARTS AGE
nginx1 1/1 Running 0 48m
#檢視所有名稱空間和標籤
[root@master /]# kubectl get pods --all-namespaces --show-labels
#檢視這個鍵app對應的值是什麼
[root@master /]# kubectl get pods -L app
NAME READY STATUS RESTARTS AGE APP
nginx1 1/1 Running 0 50m nginx-pod
#刪除這個標籤
[root@master ~]# kubectl label pod nginx1 app-
pod/nginx1 unlabeled
[root@master ~]# kubectl get pod --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx1 1/1 Running 0 57m test=01
s
三、親和性
1、node節點選擇器
就是根據主機名或者標籤進行pod的排程，屬於強制性的排程，不存在的也能進行排程，是pending的狀態
1、nodename
[root@master pod]# cat pod1.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod1
namespace: test
spec:
nodeName: node1 #排程到node1主機上面
containers:
- name: pod1
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx1 1/1 Running 0 12h 10.244.104.5 node2 <none> <none>
pod1 1/1 Running 0 34s 10.244.166.130 node1 <none> <none>
2、nodeselector
#給主機名打上標籤，以便進行排程
[root@master ~]# kubectl label nodes node1 app=node1
node/node1 labeled
[root@master ~]# kubectl get nodes node1 --show-labels
NAME STATUS ROLES AGE VERSION LABELS
node1 Ready <none> 23h v1.26.0 app=node1,beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node1,kubernetes.io/os=linux
[root@master pod]# cat pod2.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod2
namespace: test
spec:
nodeSelector: #根據主機名的標籤進行排程
app: node1 #這種鍵值的形式來表現出來
containers:
- name: pod2
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx1 1/1 Running 0 12h 10.244.104.5 node2 <none> <none>
pod1 1/1 Running 0 9m28s 10.244.166.130 node1 <none> <none>
pod2 1/1 Running 0 12s 10.244.166.131 node1 <none> <none>
2、node親和性
-
根據node上面的標籤進行排程
-
根據的是node和pod之間的關係進行排程的
1、軟親和性
- 如果沒有符合條件的，就隨機選擇一個進行排程
[root@master pod]# cat pod4.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod4
namespace: test
spec:
affinity:
nodeAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- preference:
matchExpressions: #匹配節點上面的標籤
- key: app
operator: In
values: ["node1"]
weight: 1 #根據權重來排程
containers:
- name: pod4
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod3 1/1 Running 0 6m52s 10.244.166.133 node1 <none> <none>
pod4 1/1 Running 0 40s 10.244.166.135 node1 <none> <none>
2、硬親和性
[root@master pod]# cat pod3.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod3
namespace: test
spec:
affinity:
nodeAffinity:
requiredDuringSchedulingIgnoredDuringExecution: #硬限制
nodeSelectorTerms: #根據這個node上面的標籤來進行排程
- matchExpressions:
- key: app
operator: In
values: ["node1"] #排程到上面有app=node1這個標籤的節點上面去
containers:
- name: pod3
image: docker.io/library/nginx:1.9.1
imagePullPolicy: IfNotPresent
3、pod親和性
-
就是幾個pod之間有依賴的關係，就放在一起，這樣效率就快一點，網站服務和資料庫服務就需要在一起，提高效率
-
根據正在執行的pod上面的標籤進行排程
1、軟親和性
apiVersion: v1
kind: Pod
metadata:
name: pod7
namespace: test
spec:
affinity:
podAffinity:
preferredDuringSchedulingIgnoredDuringExecution:
- podAffinityTerm:
labelSelector:
matchExpressions:
- key: app
operator: In
values: ["pod4"]
topologyKey: app
weight: 1
containers:
- name: pod7
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod4 1/1 Running 0 24m 10.244.166.136 node1 <none> <none>
pod5 1/1 Running 0 21m 10.244.166.137 node1 <none> <none>
pod7 1/1 Running 0 51s 10.244.166.139 node1 <none> <none>
2、硬親和性
[root@master pod]# cat pod5.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod5
namespace: test
spec:
affinity:
podAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: app
operator: In
values: ["pod4"]
topologyKey: kubernetes.io/hostname #這個就是拓撲域，每個節點的這個都不一樣。node1,node2等
containers:
- name: pod5
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
#關於這個topologyKey的值的選擇，一般就是節點上面的標籤
apiVersion: v1
kind: Pod
metadata:
name: pod6
namespace: test
spec:
affinity:
podAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: app
operator: In
values: ["pod4"]
topologyKey: app2 #這個是node2上面的標籤，排程到pod包含這個app=pod4這個標籤，並且節點是標籤是app2上面的節點上面
containers:
- name: pod6
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
[root@master pod]# cat pod5.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod6
namespace: test
spec:
affinity:
podAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: app
operator: In
values: ["pod4"]
topologyKey: app #排程到pod包含了app的標籤，並且值在app節點上面去了
containers:
- name: pod6
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
# operator: DoesNotExist情況
apiVersion: v1
kind: Pod
metadata:
name: pod6
namespace: test
spec:
affinity:
podAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: app
operator: DoesNotExist
topologyKey: app #排程到key不包含app並且節點標籤為app的節點上面，還是排程到app節點上面去了
containers:
- name: pod6
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
4、pod反親和性
就是當2個都是佔記憶體比較高的Pod,就使用和這個反親和性進行分開
apiVersion: v1
kind: Pod
metadata:
name: pod8
namespace: test
spec:
affinity:
podAntiAffinity:
requiredDuringSchedulingIgnoredDuringExecution:
- labelSelector:
matchExpressions:
- key: app
operator: In
values: ["pod4"]
topologyKey: kubernetes.io/hostname #排程到不能包含app=pod4上面的節點，排程到node1上
containers:
- name: pod8
image: docker.io/library/nginx
imagePullPolicy: IfNotPresent
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod4 1/1 Running 0 36m 10.244.166.136 node1 <none> <none>
pod5 1/1 Running 0 33m 10.244.166.137 node1 <none> <none>
pod6 1/1 Running 0 7m42s 10.244.166.140 node1 <none> <none>
pod7 1/1 Running 0 12m 10.244.166.139 node1 <none> <none>
pod8 1/1 Running 0 8s 10.244.104.6 node2 <none> <none>=
5、汙點
-
在node上面進行打汙點
-
kubectl explain node.spec.taints -
手動打汙點，
kubectl taint nodes node1 a=b:NoSchedule -
汙點三個等級
-
NoExecute 節點上面的pod都移除掉，不能排程到這個節點上
-
NoSchedule 節點上面存在的pod保留，但是新建立的pod不能排程到這個節點上面
-
PreferNoSchedule pod不到萬不得已的情況下，才能排程到這個節點上面
-
#給node1打上一個汙點
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod4 1/1 Running 0 41m 10.244.166.136 node1 <none> <none>
pod5 1/1 Running 0 37m 10.244.166.137 node1 <none> <none>
pod6 1/1 Running 0 12m 10.244.166.140 node1 <none> <none>
pod7 1/1 Running 0 17m 10.244.166.139 node1 <none> <none>
pod8 1/1 Running 0 4m33s 10.244.104.6 node2 <none> <none>
[root@master pod]# kubectl taint node node1 app=node1:NoExecute
node/node1 tainted
#發現這個節點上面的pod都銷燬了
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod8 1/1 Running 0 6m21s 10.244.104.6 node2 <none> <none>
#去除汙點
[root@master pod]# kubectl taint node node1 app-
node/node1 untainted
[root@master pod]# kubectl describe node node1 | grep -i taint
Taints: <none>
6、容忍度
-
在pod上面進行容忍度，就是會容忍node上面的汙點,從而能進行排程
-
kubectl explain pod.spec.tolerations
#就是節點上面有汙點但是pod上面有容忍度可以容忍這個汙點來進行排程到指定的節點上面去
#給node1打上汙點
[root@master pod]# kubectl taint node node1 app=node1:NoExecute
node/node1 tainted
#進行排程到node1上
apiVersion: v1
kind: Pod
metadata:
name: pod10
namespace: test
spec:
tolerations:
- key: "app"
operator: Equal #就是key和values，effect必須和node上面完全匹配才行 #exists，只要對應的鍵是存在的，其值被自動定義成萬用字元
value: "node1"
effect: NoExecute
containers:
- name: pod10
image: docker.io/library/nginx:1.9.1
[root@master pod]# kubectl get pod -n test -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod10 1/1 Running 0 58s 10.244.166.142 node1 <none> <none>
pod8 1/1 Running 0 27m 10.244.104.6 node2 <none> <none>
apiVersion: v1
kind: Pod
metadata:
name: pod11
namespace: test
spec:
tolerations:
- key: "app"
operator: Exists #容忍無論app，NoExecute的值為多少,都能進行排程
value: ""
effect: NoExecute
containers:
- name: pod11
image: docker.io/library/nginx:1.9.1
四：pod的生命週期
-
init容器，初始化的容器，就是必須要經過這個階段才能執行主容器
-
主容器，裡面有啟動前鉤子和啟動後鉤子
1、初始化容器
[root@master pod]# cat init.yaml
apiVersion: v1
kind: Pod
metadata:
name: init-pod
namespace: test
spec:
initContainers:
- name: init-pod1
image: docker.io/library/nginx:1.9.1
command: ["/bin/bash","-c","touch /11.txt"]
containers:
- name: main-pod
image: docker.io/library/nginx:1.9.1
[root@master pod]# kubectl get pod -n test -w
NAME READY STATUS RESTARTS AGE
init-pod 0/1 Pending 0 0s
init-pod 0/1 Pending 0 0s
init-pod 0/1 Init:0/1 0 0s
init-pod 0/1 Init:0/1 0 1s
init-pod 0/1 PodInitializing 0 2s
init-pod 1/1 Running 0 3s
#如果初始化錯誤的話，會一直陷入重啟的狀態，這個跟pod的重啟策略有關
[root@master pod]# cat init.yaml
apiVersion: v1
kind: Pod
metadata:
name: init-pod
namespace: test
spec:
initContainers:
- name: init-pod1
image: docker.io/library/nginx:1.9.1
command: ["/bin/bash","-c","qwe /11.txt"]
containers:
- name: main-pod
image: docker.io/library/nginx:1.9.1
[root@master pod]# kubectl get pod -n test -w
NAME READY STATUS RESTARTS AGE
init-pod 0/1 Pending 0 0s
init-pod 0/1 Pending 0 0s
init-pod 0/1 Init:0/1 0 0s
init-pod 0/1 Init:0/1 0 0s
init-pod 0/1 Init:0/1 0 1s
init-pod 0/1 Init:Error 0 2s
init-pod 0/1 Init:Error 1 (2s ago) 3s
init-pod 0/1 Init:CrashLoopBackOff 1 (2s ago) 4s
init-pod 0/1 Init:Error 2 (14s ago) 16s
2、啟動前鉤子
-
就是在主容器執行的前，執行這個鉤子
-
失敗的話，會一直重啟(重啟策略決定的)，就不會執行主容器了
-
有三種的寫法
1、exec
[root@master pod]# cat pre.yaml
apiVersion: v1
kind: Pod
metadata:
name: pre-pod
namespace: test
spec:
containers:
- name: pre-pod
image: docker.io/library/nginx:1.9.1
lifecycle:
postStart:
exec:
command: ["/bin/bash","-c","touch /11.txt"]
[root@master pod]# kubectl exec -n test -ti pre-pod -- /bin/bash
root@pre-pod:/# ls
11.txt boot etc lib media opt root sbin sys usr
bin dev home lib64 mnt proc run srv tmp var
root@pre-pod:/# cat 11.txt
#如果啟動前鉤子鉤子報錯的話，後面的主容器不會執行了
3、啟動後鉤子
[root@master pod]# cat pre.yaml
apiVersion: v1
kind: Pod
metadata:
name: pre-pod
namespace: test
spec:
containers:
- name: pre-pod
image: docker.io/library/nginx:1.9.1
lifecycle:
preStop:
exec:
command: ["/bin/bash","-c","touch /11.txt"]
4、pod重啟策略和pod的狀態
-
用於設定pod的值
-
Always，當容器出現任何狀況的話，就自動進行重啟，這個是預設的值
-
OnFailure，當容器終止執行且退出碼不為0時，kubelet自動重啟該容器
-
Never，不論容器的狀態如何，kubelet都不會重啟該容器
-
pod的狀態
1、pending，請求建立Pod時，條件不滿足，排程沒有進行完成沒有一個節點符合，或者是處於下載映象的情況
-
running 就是已經排程到一個節點上面了，裡面的容器至少有一個建立出來了
-
succeeded pod裡面的所有容器都成功的被終止了，並且不會在重啟了
-
Failed 裡面的所有容器都已經終止了，並且至少有一個容器是因為失敗終止的，就是非0狀態重啟的
-
Unknown 未知狀態，就是apiserver和kubelet出現了問題
-
Evicted狀態，記憶體和硬碟資源不夠
-
CrashLoopBackOff 容器曾經啟動了，但是又異常退出了
-
Error pod啟動過程中發生了錯誤
-
Completed 說明pod已經完成了工作，
-
#在容器裡面設定一個啟動前鉤子，鉤子會失敗，然後重啟策略設定為Never
apiVersion: v1
kind: Pod
metadata:
name: pre-pod
namespace: test
spec:
restartPolicy: Never
containers:
- name: pre-pod
image: docker.io/library/nginx:1.9.1
lifecycle:
postStart:
exec:
command: ["/bin/bash","-c","qwe /11.txt"]
#這個鉤子失敗了，然後pod不進行重啟策略
[root@master pod]# kubectl get pod -n test -w
NAME READY STATUS RESTARTS AGE
pre-pod 0/1 Pending 0 0s
pre-pod 0/1 Pending 0 0s
pre-pod 0/1 ContainerCreating 0 0s
pre-pod 0/1 ContainerCreating 0 0s
pre-pod 0/1 Completed 0 2s
pre-pod 0/1 Completed 0 3s
pre-pod 0/1 Completed 0 4s
#檢視詳細資訊
#正常退出了
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 12m default-scheduler Successfully assigned test/pre-pod to node1
Normal Pulled 12m kubelet Container image "docker.io/library/nginx:1.9.1" already present on machine
Normal Created 12m kubelet Created container pre-pod
Normal Started 12m kubelet Started container pre-pod
Warning FailedPostStartHook 12m kubelet PostStartHook failed
Normal Killing 12m kubelet s FailedPostStartHook
五、pod健康檢查(主要就是容器裡面)
1、liveness probe(存活探測)
-
用於檢測pod內的容器是否處於執行的狀態，當這個探測失效時，k8s會根據這個重啟策略決定是否重啟改容器
-
適用於在容器發生故障時進行重啟，web程式等
-
主要就是檢測pod是否執行的
-
支援三種格式，exec,tcp，httpget
-
探測結果有三個值，Success表示透過了檢測，Failure表示未透過檢測，Unknown表示檢測沒有正常的執行
-
kubectl explain pod.spec.containers.livenessProbe
1、引數詳解
livenessProbe:
initialDelaySeconds: #pod啟動後首次進行檢查的等待時間，單位為秒
periodSeconds: #檢查的間隔時間，預設為10秒
timeoutSeconds： #探針執行檢測請求後，等待響應的超時時間，預設為1秒
successThreshold： #連續探測幾次成功，才認為探測成功，預設為1，在liveness中，必須為1，最小值為1
failureThreshold： #探測失敗的重試次數，重試一定次數後將認為失敗，在readiness探針中，Pod會被標記未就緒，預設為3，最小值為1
2、exec格式
[root@master pod]# cat liveness.yaml
apiVersion: v1
kind: Pod
metadata:
name: live1
namespace: test
spec:
containers:
- name: live1
image: docker.io/library/nginx:1.9.1
livenessProbe:
exec:
command: ["/bin/bash","-c","touch /11.txt"]
failureThreshold: 3 #失敗三次就認定為失敗
initialDelaySeconds: 3 #進行探測的時候，等待三秒
periodSeconds: 5 #檢查的時間間隔為10s
successThreshold: 1 #必須為1，有1次成功即可
timeoutSeconds: 10 #執行請求後，等待的時間為10s
[root@master pod]# kubectl get pod -n test -w
NAME READY STATUS RESTARTS AGE
pre-pod 0/1 Completed 0 4h45m
live1 0/1 Pending 0 0s
live1 0/1 Pending 0 0s
live1 0/1 ContainerCreating 0 0s
live1 0/1 ContainerCreating 0 1s
live1 1/1 Running 0 2s
live1 1/1 Running 0 30s
3、httpget格式
#格式說明
httpGet:
scheme： #用於連線host的協議，預設為http
host： #要連線的主機名，預設為pod的ip，就是容器裡面的主機名
port： #容器上要訪問埠號或名稱
path: #http伺服器上的訪問url
httpHeaders： #自定義http請求headers，允許重複
[root@master pod]# cat liveness.yaml
apiVersion: v1
kind: Pod
metadata:
name: live1
namespace: test
spec:
containers:
- name: live1
image: docker.io/library/nginx:1.9.1
livenessProbe:
httpGet:
port: 80
scheme: HTTP
path: /index.html #就是在容器內部curl localhost:80/index.html檢測
failureThreshold: 3 #返回了一個成功的 HTTP 響應（狀態碼在 200-399 之間)就是成功的
initialDelaySeconds: 3
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 10
#可以執行
live1 0/1 ContainerCreating 0 0s
live1 0/1 ContainerCreating 0 1s
live1 1/1 Running 0 2s
live1 1/1 Running 0 42s
4、tcp方式健康檢查
[root@master pod]# cat liveness.yaml
apiVersion: v1
kind: Pod
metadata:
name: live1
namespace: test
spec:
containers:
- name: live1
image: docker.io/library/nginx:1.9.1
livenessProbe:
tcpSocket:
port: 80 #傳送一個探針，嘗試連線容器80埠
failureThreshold: 3
initialDelaySeconds: 3
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 10
2、readiness probe(就緒性探測)
-
就是pod裡面的容器執行了，但是提供服務的程式，需要讀取這個網頁的配置檔案，才能提供服務
-
所以的話需要這個就緒性探測，伺服器起來了，就能提供這個服務了
-
防止Pod起來了，但是裡面的服務是假的服務這種情況
-
也支援三種
[root@master pod]# cat liveness.yaml
apiVersion: v1
kind: Pod
metadata:
name: live1
namespace: test
spec:
containers:
- name: live1
image: docker.io/library/nginx:1.9.1
readinessProbe:
httpGet:
port: 80 #傳送一個請求
failureThreshold: 3
initialDelaySeconds: 3
periodSeconds: 5
successThreshold: 1
timeoutSeconds: 10
#在檢測的時候的等待幾秒鐘
[root@master pod]# kubectl get pod -n test -w
NAME READY STATUS RESTARTS AGE
pre-pod 0/1 Completed 0 5h11m
live1 0/1 Pending 0 0s
live1 0/1 Pending 0 0s
live1 0/1 ContainerCreating 0 0s
live1 0/1 ContainerCreating 0 0s
live1 0/1 Running 0 1s
live1 1/1 Running 0 5s