kubernetes集群核心概念---pod
1.pod介绍
参考链接: https://kubernetes.io/zh/docs/concepts/workloads/pods/
1.1.查看pod
[root@centos ~]# kubectl get pod # pod或pods都可以，不指定namespace,默认是名为default的namespace
[root@centos ~]# kubectl get pod -n kube-system
1.2.pod的yaml资源清单格式
apiVersion: v1
kind: Pod
metadata:
name:
labels:
spec:
hostNetwork: true|false
nodeName: "指定的节点名称必须在etcd中有记录"
volumes:
- name: data01
emptyDir:{}
- name: data02
hostPath:
path:
- name: data03
nfs:
server:
path:
- name: data04
configMap:
name:
items:
contaners:
- name:
image:
env:
- name:
value:
- name:
value:
command: []
args: []
ports:
- containerPort:
hostIP:
hostPort:
name:
protocol:
imagePullPolicy: Alwasy|Never|IfNotPresent
resources:
request:
cpu:
memory:
limits:
cpu:
memory:
volumeMounts:
- name:
mountPath:
status:
1.3.yaml格式查找帮助方法
[root@centos ~]# kubectl explain namespace
[root@centos ~]# kubectl explain pod
[root@centos ~]# kubectl explain pod.spec
[root@centos ~]# kubectl explain pod.spec.containers
2.pod创建
2.1.创建一个名为pod-nginx的pod
[root@centos ~]# kubectl run nginx1 --image=nginx:1.15-alpine
pod/nginx1 created
[root@centos ~]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx1 1/1 Running 0 41s
2.2.YAML创建pod
[root@centos ~]# vim pod1.yml
apiVersion: v1 # api版本
kind: Pod # 资源类型为Pod
metadata:
name: pod-test-stress # 自定义pod的名称
spec:
containers: # 定义pod里包含的容器
- name: c1 # 自定义pod中的容器名
image: polinux/test-stress # 启动容器的镜像名
command: ["test-stress"] # 自定义启动容器时要执行的命令(类似dockerfile里的CMD)
args: ["--vm", "1", "--vm-bytes", "150M", "--vm-hang", "1"] # 自定义启动容器执行命令的参数
# polinux/test-stress这个镜像用于压力测试,在启动容器时传命令与参数就是相当于分配容器运行时需要的压力
[root@centos ~]# kubectl apply -f pod1.yml
pod/pod-test-stress created
3.查看pod信息
3.1.查看pod信息
[root@centos ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod-test-stress 1/1 Running 0 20s
3.2.查看pod详细信息
[root@centos ~]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES
pod-test-stress 1/1 Running 0 71s 10.244.194.72 k8s-worker1 <none> <none>
3.3.描述pod详细信息
[root@k8s-master1 ~]# kubectl describe pod pod-test-stress
......
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 102s default-scheduler Successfully assigned default/pod-test-stress to k8s-worker1
Normal Pulling 102s kubelet Pulling image "polinux/test-stress"
Normal Pulled 83s kubelet Successfully pulled image "polinux/test-stress" in 18.944533343s
Normal Created 83s kubelet Created container c1
Normal Started 82s kubelet Started container c1
4.删除pod
4.1.单个pod删除
# kubectl delete pod pod-test-stress
# kubectl delete -f pod1.yml
4.2.多个pod删除
# kubectl delete pod pod名1 pod名2 pod名3 ......
# kubectl get pods |awk 'NR>1 {print $1}' |xargs kubectl delete pod
# kubectl delete ns xxxx
5.pod标签
5.1.查看pod标签
kubectl get pods --show-labels
5.2.打标签并查看
# kubectl label pod pod-test-stress region=huanai zone=A env=test-stress bussiness=game
pod/pod-test-stress labeled
# kubectl get pods --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-test-stress 1/1 Running 0 8m54s bussiness=game,env=test-stress,region=huanai,zone=A
5.3.通过等值关系标签查询
# kubectl get pods -l zone=A
NAME READY STATUS RESTARTS AGE
pod-test-stress 1/1 Running 0 9m22s
5.4.通过集合关系标签查询
kubectl get pods -l "zone in (A,B,C)"
NAME READY STATUS RESTARTS AGE
pod-test-stress 1/1 Running 0 9m55s
5.5.删除标签后再验证
[root@k8s-master1 ~]# kubectl label pod pod-stress region- zone- env- bussiness-
pod/pod-test-stress labeled
[root@k8s-master1 ~]# kubectl get pods --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-test-stress 1/1 Running 0 16m <none>
5.6.通过YAML创建Pod时添加标签
1.修改yaml
# vim pod1.yml
apiVersion: v1
kind: Pod
metadata:
name: pod-test-stress
namespace: default
labels:
env: dev
app: nginx # 直接在原来的yaml里加上多个标签
spec:
containers:
- name: c1
image: polinux/stress
command: ["stress"]
args: ["--vm", "1", "--vm-bytes", "150M", "--vm-hang", "1"]
imagePullPolicy: IfNotPresent
2.直接apply应用
# kubectl apply -f pod1.yaml
pod/pod-stress1 configured
3.验证
kubectl get pods --show-labels
NAME READY STATUS RESTARTS AGE LABELS
pod-test-stress 1/1 Running 0 3m5s app=nginx,env=dev
