Kubernets 资源对象

资源：对象

workload
- Pod
- ReplicaSet
- Deployment
- StaticfulSet
- DaemonSet
- Job
- Cronjob
服务发现与负载均衡
- Service
- Ingress
配置存储
- Volume CSI
- ConfigMap，
- Secret
- DownwandAPI
集群资源
- Namespace
- Node Role
- ClusterRole
- RoleBinding
- ClusterRoleBinding
元数据型资源
- HPA
- PodTemplate
- LimitRange

查看各资源yaml配置使用

kubectl explain pod  这里pod为资源类型 可以写其他资源 
kubectl explain pod.spec

1.POD

作为最小单位，由以下一级字段组成，具体说明请查看 http://www.jcwit.com/?p=493

apiVersion api版本此值必须在kubectl apiversion中
kind 指定资源类型这里是Pod
metadata meta信息，比如名称、namespace、标签等信息
spec 包括一些container，storage，volume以及其他Kubernetes需要的参数，以及诸如是否在容器失败时重新启动容器的属性
status（由系统定义该字段）

2. ReplicaSet

控制pod的副本数量由以下一级字段组成

apiVersion api版本此值必须在kubectl apiversion中
kind 指定资源类型这里是ReplicaSet
metadata meta信息，比如名称、namespace、标签等信息
spec 需要指定以下字段
- replicas 副本数量
- selector选择器
- template pod模板
selector标签选择器
- 等值关系 = == ！=
- 集合关系
- key in （value1， value2）
- key not in （value，value2）
- key
- !key

许多资源支持内嵌字段定义标签选择器
matchLabels：直接给键值
matchExpressions: 基于给定表达式定义标签

[root@node1 ~]# cat nginx-rs.yaml 
apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: nginx-rs
  namespace: default
  labels:
    web: nginx
spec:
  replicas: 2   #指定副本数量
  selector:
    matchLabels:   指定匹配标签
      app: nginx
  template:
    metadata:
       labels:     对应上面的selector标签
         app: nginx
    spec:               #下面是容器定义和pod.spec一样
      containers:
      - name: nginx
        image: daocloud.io/library/nginx
        imagePullPolicy: IfNotPresent 
        ports:
        - containerPort: 80

更新

[root@node1 ~]# kubectl set image rs nginx-rs nginx=daocloud.io/library/nginx:1.12
replicaset.extensions/nginx-rs image updated

通过挨个删除其中一个pod 然后让其重构实现版本更新（灰度发布）

3. Deployment 类似于rs

由以下字段组成

apiVersion：
kind 这里为Deployment
metadata meta信息，比如名称、namespace、标签等信息
spec需要指定以下字段
- replicas 副本数量
- selector选择器
- template pod模板

[root@node1 ~]# cat nginx.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deployment
  namespace: default
  labels:
     web: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
       app: nginx
  template:
    metadata:
       labels:
         app: nginx
    spec:
      containers:
      - name: nginx
        image: daocloud.io/library/nginx
        imagePullPolicy: IfNotPresent 
         ports:
         - containerPort: 80

kubectl apply -f nginx.yaml

更新 (蓝绿发布)

[root@node1 ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deployment-587ccff74 2 2 2 155m
[root@node1 ~]# kubectl set image deploy nginx-deployment nginx=daocloud.io/library/nginx:1.12
deployment.extensions/nginx-deployment image updated
[root@node1 ~]# kubectl get rs     #这里会产生两个rs,用来回滚
NAME DESIRED CURRENT READY AGE
nginx-deployment-587ccff74 0 0 0 157m
nginx-deployment-8d64b797d 2 2 1 9s

通过打补丁方式修改资源

[root@node1 ~]# kubectl patch deploy nginx-deployment -p '{"spec":{"replicas":5}}'
deployment.extensions/nginx-deployment patched

允许多一个pod

[root@node1 ~]# kubectl patch deployment nginx-deployment -p '{"spec":{"strategy":{"rollingUpdate":{"maxSurge":1,"maxUnavailable":0}}}}'
deployment.extensions/nginx-deployment patched

实现金丝雀发布

执行暂停操作

[root@node1 ~]# kubectl set image deploy nginx-deployment nginx=daocloud.io/library/nginx:1.11 && kubectl rollout pause deploy nginx-deployment
deployment.extensions/nginx-deployment image updated
deployment.extensions/nginx-deployment paused

实时查看pod状态发现多了一个pod 卡在了删除容器

[root@node1 ~]# kubectl get pods -w 
NAME READY STATUS RESTARTS AGE
nginx-deployment-79fbdccf57-sr4v6 0/1 ContainerCreating 0 20s
nginx-deployment-8d64b797d-8x8lh 1/1 Running 0 9m33s
nginx-deployment-8d64b797d-frwmw 1/1 Running 0 17m
nginx-deployment-8d64b797d-qtczc 1/1 Running 0 9m33s
nginx-deployment-8d64b797d-rsjl9 1/1 Running 0 9m33s
nginx-deployment-8d64b797d-xr5x6 1/1 Running 0 17m
nginx-deployment-79fbdccf57-sr4v6 1/1 Running 0 36s

确认没问题后执行以下操作关闭暂停

[root@node1 ~]# kubectl rollout resume deploy nginx-deployment
deployment.extensions/nginx-deployment resumed

查看更新状态

[root@node1 ~]# kubectl rollout status deploy nginx-deployment
Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 5 new replicas have been updated...
Waiting for deployment spec update to be observed...
Waiting for deployment spec update to be observed...
Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 1 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 2 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 3 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 3 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 3 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 4 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 4 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 4 out of 5 new replicas have been updated...
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
Waiting for deployment "nginx-deployment" rollout to finish: 1 old replicas are pending termination...
deployment "nginx-deployment" successfully rolled out

4.DaemonSet

和Deployment 相似

kind： DaemonSet

没有replicas 会在每个node上运行一个pod，新加入的Node也同样会自动运行一个Pod

查看pod发现每个节点运行一个

[root@node1 ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
nginx-deployment-dmmnb 1/1 Running 0 14s 10.254.60.3 192.168.57.14 <none> <none>
nginx-deployment-p88k7 1/1 Running 0 14s 10.254.60.2 192.168.57.15 <none> <none>

k8s

Kubernets 资源对象

http://www.jcwit.com/article/51/

作者

Carlos

发布于

2019年5月7日

许可协议

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