服务器版本 docker软件版本 CPU架构 CentOS Linux release 7.4.1708 (Core) Docker version 20.10.12 x86_64
一个pod里可以有一个容器，也可以有多个容器。
一般一个pod里运行一个容器，那一个pod里运行两个容器的意义何在？一个容器是主容器，一个是副容器sidecar,比如nginx容器用来提供服务，另外一个容器使用工具来进行日志分析，两个容器挂载同一个数 据卷，日志分析容器读取数据卷即可分析日志。
3.1 环境介绍
Kubernetes集群架构：k8scloude1作为master节点，k8scloude2，k8scloude3作为worker节点
服务器 操作系统版本 CPU架构 进程 功能描述 k8scloude1/192.168.110.130 CentOS Linux release 7.4.1708 (Core) x86_64 docker，kube-apiserver，etcd，kube-scheduler，kube-controller-manager，kubelet，kube-proxy，coredns，calico k8s master节点 k8scloude2/192.168.110.129 CentOS Linux release 7.4.1708 (Core) x86_64 docker，kubelet，kube-proxy，calico k8s worker节点 k8scloude3/192.168.110.128 CentOS Linux release 7.4.1708 (Core) x86_64 docker，kubelet，kube-proxy，calico k8s worker节点
3.2 在一个pod里创建多个容器
生成一个yaml文件，pod里面有2个容器n1，n2
[root@k8scloude1 pod]# vim pod2.yaml
#kind: Pod表示资源类型为Pod labels指定pod标签 metadata下面的name指定pod名字 containers下面全是容器的定义
#image指定镜像名字 imagePullPolicy指定镜像下载策略 containers下面的name指定容器名
#resources指定容器资源（CPU，内存等） dnsPolicy指定DNS策略 restartPolicy容器重启策略
[root@k8scloude1 pod]# cat pod2.yaml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: pod1
name: pod1
spec:
containers:
- image: nginx
imagePullPolicy: IfNotPresent
name: n1
resources: {}
- image: nginx
imagePullPolicy: IfNotPresent
name: n2
resources: {}
dnsPolicy: ClusterFirst
restartPolicy: Always
status: {}
创建pod
[root@k8scloude1 pod]# kubectl apply -f pod2.yaml
pod/pod1 created
查看pod，pod启动失败，原因为使用了同一个镜像，端口80冲突
[root@k8scloude1 pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod1 1/2 CrashLoopBackOff 2 40s
[root@k8scloude1 pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod1 1/2 Error 3 58s
删除pod
[root@k8scloude1 pod]# kubectl delete pod pod1 --force
warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely.
pod "pod1" force deleted
对于containers，如果没有指定command参数，则运行的进程为nginx镜像里指定的CMD那个进程，如果有command参数，则运行command指定的进程，不运行nginx镜像里CMD的进程。
command: [“sh”,”-c”,”sleep 1000″] 睡眠1000秒，时间到了就结束了，需要进行重启，继续sleep 1000
[root@k8scloude1 pod]# vim pod2.yaml
[root@k8scloude1 pod]# cat pod2.yaml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: pod1
name: pod1
spec:
containers:
- image: nginx
imagePullPolicy: IfNotPresent
name: n1
resources: {}
- image: nginx
imagePullPolicy: IfNotPresent
command: ["sh","-c","sleep 1000"]
name: n2
resources: {}
dnsPolicy: ClusterFirst
restartPolicy: Always
status: {}
创建pod并查看，READY：2/2表示pod里有两个容器，两个容器都启动起来了。
一般一个pod里运行一个容器，那一个pod里运行两个容器的意义何在？则一个容器是主容器，一个是副容器sidecar,比如nginx容器用来提供服务，另外一个容器使用工具来进行日志分析，两个容器挂载同一个数 据卷，日志分析容器读取数据卷即可分析日志。
[root@k8scloude1 pod]# kubectl apply -f pod2.yaml
pod/pod1 created
[root@k8scloude1 pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod1 2/2 Running 0 5s
删除pod
[root@k8scloude1 pod]# kubectl delete pod pod1 --force
warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely.
pod "pod1" force deleted
[root@k8scloude1 pod]# kubectl get pod
No resources found in pod namespace.
command: [“sh”,”-c”,”sleep 10″] 修改睡眠时间为10秒
[root@k8scloude1 pod]# vim pod2.yaml
[root@k8scloude1 pod]# cat pod2.yaml
apiVersion: v1
kind: Pod
metadata:
creationTimestamp: null
labels:
run: pod1
name: pod1
spec:
containers:
- image: nginx
imagePullPolicy: IfNotPresent
name: n1
resources: {}
- image: nginx
imagePullPolicy: IfNotPresent
command: ["sh","-c","sleep 10"]
name: n2
resources: {}
dnsPolicy: ClusterFirst
restartPolicy: Always
status: {}
由于restartPolicy: Always，10秒到期之后，pod会自动进行重启
[root@k8scloude1 pod]# kubectl apply -f pod2.yaml
pod/pod1 created
[root@k8scloude1 pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod1 2/2 Running 0 5s
[root@k8scloude1 pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod1 2/2 Running 2 45s
[root@k8scloude1 pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod1 1/2 CrashLoopBackOff 3 2m3s
[root@k8scloude1 pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
pod1 1/2 CrashLoopBackOff 5 4m55s
删除pod
[root@k8scloude1 pod]# kubectl delete -f pod2.yaml --force
warning: Immediate deletion does not wait for confirmation that the running resource has been terminated. The resource may continue to run on the cluster indefinitely.
pod "pod1" force deleted
[root@k8scloude1 pod]# kubectl get pod
No resources found in pod namespace.
Original: https://www.cnblogs.com/renshengdezheli/p/16701447.html
Author: 人生的哲理
Title: pod(二)：创建包含多个容器的pod（sidecar）
原创文章受到原创版权保护。转载请注明出处：https://www.johngo689.com/582021/
转载文章受原作者版权保护。转载请注明原作者出处！