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17、Kubernetes - 资源清单 - 常用字段说明

发布时间：2022-12-11 21:31:25编辑：雪饮阅读（）

Step1

查看pod模板

[root@k8s-master01 ~]# kubectl explain pod

KIND: Pod

VERSION: v1

DESCRIPTION:

Pod is a collection of containers that can run on a host. This resource is

created by clients and scheduled onto hosts.

FIELDS:

apiVersion <string>

APIVersion defines the versioned schema of this representation of an

object. Servers should convert recognized schemas to the latest internal

value, and may reject unrecognized values. More info:

https://git.k8s.io/community/contributors/devel/api-conventions.md#resources

kind <string>

Kind is a string value representing the REST resource this object

represents. Servers may infer this from the endpoint the client submits

requests to. Cannot be updated. In CamelCase. More info:

https://git.k8s.io/community/contributors/devel/api-conventions.md#types-kinds

metadata <Object>

Standard object's metadata. More info:

https://git.k8s.io/community/contributors/devel/api-conventions.md#metadata

spec <Object>

Specification of the desired behavior of the pod. More info:

https://git.k8s.io/community/contributors/devel/api-conventions.md#spec-and-status

status <Object>

Most recently observed status of the pod. This data may not be up to date.

Populated by the system. Read-only. More info:

https://git.k8s.io/community/contributors/devel/api-conventions.md#spec-and-status

查看某个pod模板更详细的信息

[root@k8s-master01 ~]# kubectl explain pod.apiVersion

KIND: Pod

VERSION: v1

FIELD: apiVersion <string>

DESCRIPTION:

APIVersion defines the versioned schema of this representation of an

object. Servers should convert recognized schemas to the latest internal

value, and may reject unrecognized values. More info:

https://git.k8s.io/community/contributors/devel/api-conventions.md#resources

示例2，这个pod模板详细内容太多就不贴命令回显结果了

kubectl explain pod.spec

step2

定义一个pod

[root@k8s-master01 ~]# vim pod.yaml

[root@k8s-master01 ~]# cat pod.yaml

apiVersion: v1

kind: Pod

metadata:

name: myapp-pod

labels:

app: myapp

spec:

containers:

- name: app

image: hub.atguigu.com/library/myapp:v1

- name: test

image: hub.atguigu.com/library/myapp:v1

该pod的容器列表是两个都使用80端口的镜像（那么会有冲突的）

该pod定义文件中键与值之间需要有空格（冒号后面）

并且不要用tab缩进，自己写空格进行缩进。

然后应用该pod定义文件

[root@k8s-master01 ~]# kubectl apply -f pod.yaml

pod/myapp-pod created

然后查看pod列表中，刚才这个pod是有问题的

[root@k8s-master01 ~]# kubectl get pod

NAME READY STATUS RESTARTS AGE

myapp-pod 1/2 CrashLoopBackOff 4 2m48s

nginx-deployment-85756b779-dljnk 1/1 Running 2 24h

nginx-deployment-85756b779-f45wk 1/1 Running 1 24h

nginx-deployment-85756b779-hgr9q 1/1 Running 3 2d22h

restarts字段显示的是重启的次数，就是说遇到了错误尝试重启了4次还是失败。（毕竟是端口占用呗）

Step3

那么到底是那个容器启动失败了呢？因为我们这个pod内部包含两个容器的

[root@k8s-master01 ~]# kubectl describe pod myapp-pod

Name: myapp-pod

Namespace: default

Priority: 0

Node: k8s-node01/192.168.66.20

Start Time: Sun, 11 Dec 2022 21:15:42 +0800

Labels: app=myapp

Annotations: kubectl.kubernetes.io/last-applied-configuration:

{"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"labels":{"app":"myapp"},"name":"myapp-pod","namespace":"default"},"spec":{"c...

Status: Running

IP: 10.224.1.17

Containers:

app:

Container ID: docker://ea7a8d65a89e44491e1209aecbb1d31154e920c862ba3dd105ff5310b7428b54

Image: hub.atguigu.com/library/myapp:v1

Image ID: docker-pullable://hub.atguigu.com/library/myapp@sha256:9eeca44ba2d410e54fccc54cbe9c021802aa8b9836a0bcf3d3229354e4c8870e

Port: <none>

Host Port: <none>

State: Running

Started: Sun, 11 Dec 2022 21:15:43 +0800

Ready: True

Restart Count: 0

Environment: <none>

Mounts:

/var/run/secrets/kubernetes.io/serviceaccount from default-token-xt842 (ro)

test:

Container ID: docker://5dfc8f8e898ba22a7546abf3f01a87dd53ddf550a6ae5b2a3e416248f9fc3e72

Image: hub.atguigu.com/library/myapp:v1

Image ID: docker-pullable://hub.atguigu.com/library/myapp@sha256:9eeca44ba2d410e54fccc54cbe9c021802aa8b9836a0bcf3d3229354e4c8870e

Port: <none>

Host Port: <none>

State: Waiting

Reason: CrashLoopBackOff

Last State: Terminated

Reason: Error

Exit Code: 1

Started: Sun, 11 Dec 2022 21:18:48 +0800

Finished: Sun, 11 Dec 2022 21:18:51 +0800

Ready: False

Restart Count: 5

Environment: <none>

Mounts:

/var/run/secrets/kubernetes.io/serviceaccount from default-token-xt842 (ro)

Conditions:

Type Status

Initialized True

Ready False

ContainersReady False

PodScheduled True

Volumes:

default-token-xt842:

Type: Secret (a volume populated by a Secret)

SecretName: default-token-xt842

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 5m16s default-scheduler Successfully assigned default/myapp-pod to k8s-node01

Normal Pulled 5m15s kubelet, k8s-node01 Container image "hub.atguigu.com/library/myapp:v1" already present on machine

Normal Created 5m15s kubelet, k8s-node01 Created container app

Normal Started 5m15s kubelet, k8s-node01 Started container app

Normal Pulled 3m40s (x5 over 5m15s) kubelet, k8s-node01 Container image "hub.atguigu.com/library/myapp:v1" already present on machine

Normal Created 3m40s (x5 over 5m15s) kubelet, k8s-node01 Created container test

Normal Started 3m40s (x5 over 5m15s) kubelet, k8s-node01 Started container test

Warning BackOff 4s (x24 over 5m9s) kubelet, k8s-node01 Back-off restarting failed container

可以看到app容器没有问题，test容器挂了，这里猜测应该是按pod定义上面的容器顺序进行运行的，所以app优先占用了80端口，然后test运行时候就没有办法运行了。

查看当前pod的test容器的日志

[root@k8s-master01 ~]# kubectl log myapp-pod -c test

log is DEPRECATED and will be removed in a future version. Use logs instead.