linuxea:kubernetes v1.11.2编写一个资源清单yaml文件(3)


创建资源中,apiserver只接受JSON格式的资源定义,此前使用的run命令,只不过是自动转换成JSON格式而已。但是JSON太过于重量,使用YAML格式来提供配置清单,apiserver会自动将yaml无损转换为JSON模式,并且不需要多余的信息,而后在提交执行
而后会通过资源配置清单,创建一个Yaml的文件来管理自主式的POD资源。其中需要遵循几个字段:apiversion,kind,metadata,spec,status

[root@linuxea ~]# kubectl get pod
NAME                             READY     STATUS    RESTARTS   AGE
client-linuxea                   1/1       Running   0          21h
nginx-linuxea-5786698598-8qt5n   1/1       Running   0          21h
nginx-linuxea-5786698598-9w5z7   1/1       Running   0          21h
nginx-linuxea-5786698598-xl9xp   1/1       Running   0          21h

I. yaml文件

查看输出yaml

[root@linuxea ~]# kubectl get pod nginx-linuxea-5786698598-8qt5n -o yaml
属性名        属性值
apiVersion: v1    ===>> k8s名称和版本  ,group/name version
kind: Pod   ===>>   类别
metadata:   ===>>   原数据
  creationTimestamp: 2018-08-23T15:22:34Z
  generateName: nginx-linuxea-5786698598-
  labels:
    pod-template-hash: "1342254154"
    run: nginx-linuxea
  name: nginx-linuxea-5786698598-8qt5n
  namespace: default
  ownerReferences:
  - apiVersion: apps/v1
    blockOwnerDeletion: true
    controller: true
    kind: ReplicaSet
    name: nginx-linuxea-5786698598
    uid: 993df65c-a6de-11e8-9c95-88882fbd1028
  resourceVersion: "122893"
  selfLink: /api/v1/namespaces/default/pods/nginx-linuxea-5786698598-8qt5n
  uid: 5c6294c1-a6e8-11e8-9c95-88882fbd1028
spec:    ===>> 规格字段,期望的目标的状态,用户定义的
  containers:
  - image: marksugar/nginx:1.14.a
    imagePullPolicy: IfNotPresent
    name: nginx-linuxea
    ports:
    - containerPort: 8787
      protocol: TCP
    resources: {}
    terminationMessagePath: /dev/termination-log
    terminationMessagePolicy: File
    volumeMounts:
    - mountPath: /var/run/secrets/kubernetes.io/serviceaccount
      name: default-token-l2x78
      readOnly: true
  dnsPolicy: ClusterFirst
  nodeName: linuxea.node-1.com
  priority: 0
  restartPolicy: Always
  schedulerName: default-scheduler
  securityContext: {}
  serviceAccount: default
  serviceAccountName: default
  terminationGracePeriodSeconds: 30
  tolerations:
  - effect: NoExecute
    key: node.kubernetes.io/not-ready
    operator: Exists
    tolerationSeconds: 300
  - effect: NoExecute
    key: node.kubernetes.io/unreachable
    operator: Exists
    tolerationSeconds: 300
  volumes:
  - name: default-token-l2x78
    secret:
      defaultMode: 420
      secretName: default-token-l2x78
status:   ===>>  显示当前资源的当前状态,只读
  conditions:
  - lastProbeTime: null
    lastTransitionTime: 2018-08-23T15:22:34Z
    status: "True"
    type: Initialized
  - lastProbeTime: null
    lastTransitionTime: 2018-08-23T15:22:35Z
    status: "True"
    type: Ready
  - lastProbeTime: null
    lastTransitionTime: null
    status: "True"
    type: ContainersReady
  - lastProbeTime: null
    lastTransitionTime: 2018-08-23T15:22:34Z
    status: "True"
    type: PodScheduled
  containerStatuses:
  - containerID: docker://8e340023d553c2de65a043eb9d643c42b9961a75440eda8a0334494e51da0f89
    image: marksugar/nginx:1.14.a
    imageID: docker-pullable://marksugar/nginx@sha256:103dd97b01c3283b56a587e7d95135f8fc410be1df36477d2d477a41f00daa59
    lastState: {}
    name: nginx-linuxea
    ready: true
    restartCount: 0
    state:
      running:
        startedAt: 2018-08-23T15:22:35Z
  hostIP: 10.10.240.202
  phase: Running
  podIP: 172.16.1.14
  qosClass: BestEffort
  startTime: 2018-08-23T15:22:34Z

大部分的资源配置清单中,都由五个字段组成

  • apiversion

apiversion: 组名/版本,可参考$kubectl api-versions。其中可以进行多次分组,测试,bete等多版本兼容同时存在

[root@linuxea ~]# kubectl api-versions
admissionregistration.k8s.io/v1beta1
apiextensions.k8s.io/v1beta1
apiregistration.k8s.io/v1
apiregistration.k8s.io/v1beta1
apps/v1
apps/v1beta1
apps/v1beta2
authentication.k8s.io/v1
authentication.k8s.io/v1beta1
authorization.k8s.io/v1
authorization.k8s.io/v1beta1
autoscaling/v1
autoscaling/v2beta1
batch/v1
batch/v1beta1
certificates.k8s.io/v1beta1
events.k8s.io/v1beta1
extensions/v1beta1
networking.k8s.io/v1
policy/v1beta1
rbac.authorization.k8s.io/v1
rbac.authorization.k8s.io/v1beta1
scheduling.k8s.io/v1beta1
storage.k8s.io/v1
storage.k8s.io/v1beta1
v1
  • kind

kind资源类别。如:Pod,ReplicaSet,Deployment,StatefulSet,DaemonSet,Job,Service等

  • metadata

metadata元数据:
​ name: 同一资源下,name是唯一的,受限于namespace
​ labels:标签
annotations:资源注解
​ selfLink
​ 资源引用的PATH注解:/api/群组/版本/namespaces/NAMESPACE(名称空间)/TYPE(资源类别)/NAME

  • spec:期望状态

spec可能会嵌套很多二级三级字段,不同的资源类型,其spec需要嵌套的字段各不相同。其中标记为resources的是必选字段,其他的均为可选字段。这些用来定义用户的期望状态

  • status:当前状态

本字段是kubernetes集群维护,用户是不能定义的

假如需要定义一个pod,可使用kubectl explain pod来查看需要的字段说明,此刻若是想知道metadata字段,则可在后面加上.matadate,如: kubectl explain pod.metadata。当然,他可以多层嵌套

[root@linuxea ~]# kubectl explain pod
[root@linuxea ~]# kubectl explain pod.metadata
[root@linuxea ~]# kubectl explain pods.spec
[root@linuxea ~]# kubectl explain pods.spec.containers
[root@linuxea ~]# kubectl explain pods.spec.containers.tty

II. 定义资源

为了测试,定义三个容器在一个pod中,三个容器都不同

[root@linuxea linuxea]# cat pod-demo.yaml 
apiVersion: v1
kind: Pod
metadata: 
  name: pod-demo-linuxea
  namespace: default
  labels:
    www: linuxea-com
    tier: backend
spec:
  containers:
  - name: linuxea-pod1-com
    image: "marksugar/nginx:1.14.a"
    ports:
      - containerPort: 88
  - name: linuxea-pod2-com
    image: "marksugar/nginx:1.14.b"
    ports:
      - containerPort: 88
  - name: alpine
    image: "alpine:3.8"
    command: 
    - "/bin/sh"
    - "-c"
    - "tail -f /etc/passwd"

使用yaml文件的方式就不在是run,而是create

[root@linuxea linuxea]# kubectl create -f pod-demo.yaml 
pod/pod-demo-linuxea created

这里有一个ContainerCreating的过程,而后就running起来

[root@linuxea linuxea]# kubectl get pod -o wide
NAME               READY     STATUS    RESTARTS   AGE       IP             NODE                 NOMINATED NODE
client-linuxea     1/1       Running   0          23h       172.16.2.252   linuxea.node-2.com   <none>
pod-demo-linuxea   1/3       ContainerCreating   0          3s        172.16.3.23    linuxea.node-3.com   <none>
[root@linuxea linuxea]# kubectl get pod -o wide
NAME               READY     STATUS    RESTARTS   AGE       IP             NODE                 NOMINATED NODE
client-linuxea     1/1       Running   0          23h       172.16.2.252   linuxea.node-2.com   <none>
pod-demo-linuxea   3/3       Running   0          3s        172.16.3.23    linuxea.node-3.com   <none>

使用kubectl describe pods pod-demo-linuxea查看定义的pod信息

[root@linuxea linuxea]# kubectl describe pods pod-demo-linuxea
Name:               pod-demo-linuxea
Namespace:          default
Priority:           0
PriorityClassName:  <none>
Node:               linuxea.node-3.com/10.10.240.146
Start Time:         Fri, 24 Aug 2018 15:25:26 +0100
Labels:             tier=backend
                    www=linuxea-com
Annotations:        <none>
Status:             Running
IP:                 172.16.3.23
Containers:
  linuxea-pod1-com:
    Container ID:   docker://7c845c4640e74d6d542a3a18c5b2de69719dc74649207431a62f4f525843f15f
    Image:          marksugar/nginx:1.14.a
    Image ID:       docker-pullable://marksugar/nginx@sha256:103dd97b01c3283b56a587e7d95135f8fc410be1df36477d2d477a41f00daa59
    Port:           88/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Fri, 24 Aug 2018 15:25:26 +0100
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-l2x78 (ro)
  linuxea-pod2-com:
    Container ID:   docker://0c75ff2650b0b26b7b909858fb9f7d6259b1b17da1b161073757334237711846
    Image:          marksugar/nginx:1.14.b
    Image ID:       docker-pullable://marksugar/nginx@sha256:f6998c772d71c6fd0398963b575833bfddac1c996095a3c9a4ba59953d2a05ec
    Port:           88/TCP
    Host Port:      0/TCP
    State:          Running
      Started:      Fri, 24 Aug 2018 15:25:26 +0100
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-l2x78 (ro)
  alpine:
    Container ID:  docker://df9e005ff05e4e40f3603f7b8704c47424c3c1427a2648514f5778c7fe5ad306
    Image:         alpine:3.8
    Image ID:      docker-pullable://alpine@sha256:7043076348bf5040220df6ad703798fd8593a0918d06d3ce30c6c93be117e430
    Port:          <none>
    Host Port:     <none>
    Command:
      /bin/sh
      -c
      tail -f /etc/passwd
    State:          Running
      Started:      Fri, 24 Aug 2018 15:25:27 +0100
    Ready:          True
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-l2x78 (ro)
Conditions:
  Type              Status
  Initialized       True 
  Ready             True 
  ContainersReady   True 
  PodScheduled      True 
Volumes:
  default-token-l2x78:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-l2x78
    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  3m    default-scheduler            Successfully assigned default/pod-demo-linuxea to linuxea.node-3.com
  Normal  Pulled     3m    kubelet, linuxea.node-3.com  Container image "marksugar/nginx:1.14.a" already present on machine
  Normal  Created    3m    kubelet, linuxea.node-3.com  Created container
  Normal  Started    3m    kubelet, linuxea.node-3.com  Started container
  Normal  Pulled     3m    kubelet, linuxea.node-3.com  Container image "marksugar/nginx:1.14.b" already present on machine
  Normal  Created    3m    kubelet, linuxea.node-3.com  Created container
  Normal  Started    3m    kubelet, linuxea.node-3.com  Started container
  Normal  Pulled     3m    kubelet, linuxea.node-3.com  Container image "alpine:3.8" already present on machine
  Normal  Created    3m    kubelet, linuxea.node-3.com  Created container
  Normal  Started    3m    kubelet, linuxea.node-3.com  Started container

可以使用kubectl logs pod-demo-linuxea查看

[root@linuxea linuxea]# kubectl logs pod-demo-linuxea 
Error from server (BadRequest): a container name must be specified for pod pod-demo-linuxea, choose one of: [linuxea-pod1-com linuxea-pod2-com alpine]

或者这样

[root@linuxea linuxea]# kubectl logs linuxea-pod1-com
[root@linuxea linuxea]# kubectl logs linuxea-pod2-com
[root@linuxea linuxea]# kubectl logs linuxea-pod2-com alpine

III. 删除资源

kubectl delete -f pod-demo.yaml即可删除yaml中包含的资源,若是要回复create即可

[root@linuxea linuxea]# kubectl delete -f pod-demo.yaml 
pod "pod-demo-linuxea" deleted
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日期: 2018-08-25分类: kubernetes

标签: kubernetes

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