Pod控制器应用进阶
标签是K8s极具特色之一 一个资源可以拥有多个标签 同一个标签可以贴到不同的对象上资源配置清单： 自主式Pod资源 资源的清单格式： 一级字段：apiVersion(group/version),kind,metadata(name,namespace,labels,annotations,...),spec,status(只读) ...
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标签是K8s极具特色之一
一个资源可以拥有多个标签
同一个标签可以贴到不同的对象上
资源配置清单：
自主式Pod资源
资源的清单格式：
一级字段：apiVersion(group/version),kind,metadata(name,namespace,labels,annotations,...),spec,status(只读)
Pod资源
spec.containers <[]object>
- name <string>
image <string>
imagePullPolicy <string>
Always,Never,IfNotPresent 分别对应：总是去下载，总是不去下载，如果本地不存在就下载
示例：在yaml文件中：
spec：
containers:
imagePullPolicy: IfNotPresent
查看端口的一些信息
kubectl explain pods.spec.containers.ports
例如：
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
- name:https
containerPort: 443
标签：
key=value
key：字符，数字 _ - .只能以字母数字开头
value:可以为空，只能以字母数字开头和结尾
标签选择器：
等值关系：=,==,!=
集合关系：KEY notin(VALUE1,VALUE2)
KEY notin (VALUE1,VALUE2)
KEY
!KEY
许多资源支持内嵌字段使用标签选择器：
matchLabels：直接给定健值
matchExpressions：基于给定的表达式来使用标签选择器{key:"KEY",operator:"OPERATOR",values:[VAL1,VAL2,...]}
操作符：
In， NotIn：value字段的值必须为非空列表
Exists，NotExists:values字段的值必须为空列表
nodeSelector <map[string]string>
节点选择器标签
nodeName <string> 指定节点选择器
annotations：
和label不同的地方在于，它不能用于挑选资源对象，仅用于对象提供"元数据"
Pod的生命周期：
状态： Pending 挂起 没有能满足的，调度没有完成
Running 运行
Failed 失败
Succeeded 成功
Unknown 位置状态
创建Pod：
Pod生命周期中的重要行为：
初始化容器
容器探测：
liveness
readiness
reatartPolicy(容器的重启策略)
Always，OnFailure，Neber，Default to Always
必须重启，状态错误重启，不充钱，默认
查看所有的标签：
kubectl get pods --show-labels
[root@master manifests]# kubectl get pods --show-labels
NAME READY STATUS RESTARTS AGE LABELS
client 1/1 Running 0 15h run=client
myapp-848b5b879b-4xpl7 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-7gtn4 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-xtcdd 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h pod-template-hash=16151555,run=nginx-deploy
pod-demo 2/2 Running 0 4s app=myapp,tier=frontend指定标签过滤器：
kubectl get pods -L app
[root@master manifests]# kubectl get pods -L app
NAME READY STATUS RESTARTS AGE APP
client 1/1 Running 0 15h
myapp-848b5b879b-4xpl7 1/1 Running 0 14h
myapp-848b5b879b-7gtn4 1/1 Running 0 14h
myapp-848b5b879b-xtcdd 1/1 Running 0 14h
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h
pod-demo 2/2 Running 0 1m myapp
[root@master manifests]# kubectl get pods -l app
NAME READY STATUS RESTARTS AGE
pod-demo 2/2 Running 0 2m
[root@master manifests]# kubectl get pods -l app --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-demo 2/2 Running 0 3m app=myapp,tier=frontend
显示每一个pod的标签值
[root@master manifests]# kubectl get pods -L app --show-labels
NAME READY STATUS RESTARTS AGE APP LABELS
client 1/1 Running 0 15h run=client
myapp-848b5b879b-4xpl7 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-7gtn4 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-xtcdd 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h pod-template-hash=16151555,run=nginx-deploy
pod-demo 2/2 Running 0 3m myapp app=myapp,tier=frontend
给特定的pod增加一个标签：
kubectl label pods pod-demo release=canary
打标签之前：
[root@master manifests]# kubectl get pods -L app --show-labels
NAME READY STATUS RESTARTS AGE APP LABELS
client 1/1 Running 0 15h run=client
myapp-848b5b879b-4xpl7 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-7gtn4 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-xtcdd 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h pod-template-hash=16151555,run=nginx-deploy
pod-demo 2/2 Running 0 3m myapp app=myapp,tier=frontend
[root@master manifests]# kubectl label pods pod-demo release=canary #开始打标签
pod/pod-demo labeled
打标签之后：
[root@master manifests]# kubectl get pods -L app --show-labels
NAME READY STATUS RESTARTS AGE APP LABELS
client 1/1 Running 0 15h run=client
myapp-848b5b879b-4xpl7 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-7gtn4 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-xtcdd 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h pod-template-hash=16151555,run=nginx-deploy
pod-demo 2/2 Running 0 6m myapp app=myapp,release=canary,tier=frontend
如果已经有这个标签，再次打标签会报错的
[root@master manifests]# kubectl label pods pod-demo release=stable
error: 'release' already has a value (canary), and --overwrite is false
#已经有这个标签，如果想打上这个标签，使用--overwrite is false覆盖标签
[root@master manifests]# kubectl label pods pod-demo release=stable
error: 'release' already has a value (canary), and --overwrite is false
[root@master manifests]# kubectl label pods pod-demo release=stable --overwrite
pod/pod-demo labeled
[root@master manifests]# kubectl get pods -L app --show-labels
NAME READY STATUS RESTARTS AGE APP LABELS
client 1/1 Running 0 15h run=client
myapp-848b5b879b-4xpl7 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-7gtn4 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
myapp-848b5b879b-xtcdd 1/1 Running 0 14h pod-template-hash=4046164356,run=myapp
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h pod-template-hash=16151555,run=nginx-deploy
pod-demo 2/2 Running 0 11m myapp app=myapp,release=stable,tier=frontend筛选出来：
[root@master manifests]# kubectl get pods -l app --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-demo 2/2 Running 0 12m app=myapp,release=stable,tier=frontend
筛选有release标签的
[root@master manifests]# kubectl get pods -l release
NAME READY STATUS RESTARTS AGE
pod-demo 2/2 Running 0 13m
筛选有release和app标签的
[root@master manifests]# kubectl get pods -l release,app
NAME READY STATUS RESTARTS AGE
pod-demo 2/2 Running 0 13m
筛选出release=stable的pod
kubectl get pods -l release=stable --show-labels
[root@master manifests]# kubectl get pods -l release=stable --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-demo 2/2 Running 0 17m app=myapp,release=stable,tier=frontend我们在给别的pod打个标签
[root@master manifests]# kubectl label pods nginx-deploy-5b595999-fsxlp release=canary
pod/nginx-deploy-5b595999-fsxlp labeled
[root@master manifests]# kubectl get pods -l release --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h pod-template-hash=16151555,release=canary,run=nginx-deploy
pod-demo 2/2 Running 0 19m app=myapp,release=stable,tier=frontend
[root@master manifests]# kubectl get pods -l release=canary --show-labels
NAME READY STATUS RESTARTS AGE LABELS
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h pod-template-hash=16151555,release=canary,run=nginx-deploy
多标签筛选：
[root@master manifests]# kubectl get pods -l release,app --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-demo 2/2 Running 0 22m app=myapp,release=stable,tier=frontend
排除某一个标签：
[root@master manifests]# kubectl get pods -l release!=canary
NAME READY STATUS RESTARTS AGE
client 1/1 Running 0 15h
myapp-848b5b879b-4xpl7 1/1 Running 0 15h
myapp-848b5b879b-7gtn4 1/1 Running 0 15h
myapp-848b5b879b-xtcdd 1/1 Running 0 15h
pod-demo 2/2 Running 0 30m
包含和不包含
[root@master manifests]# kubectl get pods -l "release in (canary,beta,alpha)"
NAME READY STATUS RESTARTS AGE
nginx-deploy-5b595999-fsxlp 1/1 Running 0 15h
[root@master manifests]# kubectl get pods -l "release notin (canary,beta,alpha)"
NAME READY STATUS RESTARTS AGE
client 1/1 Running 0 16h
myapp-848b5b879b-4xpl7 1/1 Running 0 15h
myapp-848b5b879b-7gtn4 1/1 Running 0 15h
myapp-848b5b879b-xtcdd 1/1 Running 0 15h
pod-demo 2/2 Running 0 34m通过此方法也可以获得node标签
[root@master manifests]# kubectl get nodes --show-labels
NAME STATUS ROLES AGE VERSION LABELS
master Ready master 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=master,node-role.kubernetes.io/master=
node1 Ready <none> 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=node1
node2 Ready <none> 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=node2
给node1上打一个ssh的标签
[root@master manifests]# kubectl get nodes --show-labels
NAME STATUS ROLES AGE VERSION LABELS
master Ready master 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=master,node-role.kubernetes.io/master=
node1 Ready <none> 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,disktype=ssh,kubernetes.io/hostname=node1
node2 Ready <none> 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=node2
在yaml文件中定义node标签，创建时生成：
kubectl delete -f pod-node.yaml
kubectl create -f pod-node.yaml
[root@master manifests]# cat pod-demo.yaml
apiVersion: v1
kind: Pod
metadata:
name: pod-demo
namespace: default
labels:
app: myapp
tier: frontend
spec:
containers:
- name: myapp
image: ikubernetes/myapp:v1
ports:
- name: http
containerPort: 80
- name: https
containerPort: 443
- name: busybox
image: busybox:latest
imagePullPolicy: IfNotPresent #Always,Never,IfNotPresent 分别对应：总是去下载，总是不去下载，如果本地不存在就下载
command:
- "/bin/sh"
- "-c"
- "sleep 3600"
nodeSelector:
disktype: ssd
[root@master manifests]# kubectl get nodes --show-labels
NAME STATUS ROLES AGE VERSION LABELS
master Ready master 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=master,node-role.kubernetes.io/master=
node1 Ready <none> 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,disktype=ssh,kubernetes.io/hostname=node1
node2 Ready <none> 17h v1.11.2 beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/hostname=node2
资源注解：
通过：
kubectl describe pods pod-demo
yaml中添加：
apiVersion: v1
kind: Pod
metadata:
name: pod-demo
namespace: default
labels:
app: myapp
tier: frontend
annotations:
node1/create-by: "cluster admin"
显示：
Annotations: node1/create-by=cluster admin
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