文章目录
- pod的容器分类与镜像拉取策略
- pod的容器分类
- 镜像拉取策略（image PullPolicy）
- K8s私有harbor仓库部署
- 安装docker-ce，docker-compose以及他们的依赖环境还要harbor
- master节点创建一个yaml文件并将镜像下载地址修改为harbor
- 强制删除镜像方法
官方文档：https://kubernetes.io/docs/concepts/containers/images/
pod的容器分类与镜像拉取策略
pod在k8s中是：
- 最小部署单页
- 一组容器的集合
- 一个pod中的容器共享网络命名空间
- pod是短暂的
pod的容器分类
1、infrastructure container：基础容器
维护整个pod网络空间：可以在node节点操作查看容器的网络
[root@node01 ~]# cat /opt/k8s/cfg/kubelet
KUBELET_OPTS="--logtostderr=true \
--v=4 \
--hostname-override=192.168.233.132 \
--kubeconfig=/opt/k8s/cfg/kubelet.kubeconfig \
--bootstrap-kubeconfig=/opt/k8s/cfg/bootstrap.kubeconfig \
--config=/opt/k8s/cfg/kubelet.config \
--cert-dir=/opt/k8s/ssl \
--pod-infra-container-image=registry.cn-hangzhou.aliyuncs.com/google-containers/pause-amd64:3.0" '//是基础容器'2、initcontainers：初始化容器
先于业务容器开始执行，原先pod中容器是并行开启，现在进行了改进
无论容器写在初始化容器前还是写在初始化容器后，最先执行的都是初始化容器。只有初始化容器执行成功后才可以启动容器。
初始化容器的应用场景一般是多容器，例如：mysql和业务分开两个容器。将业务设为初始化容器，并检查mysql是否启动，若mysql启动，则业务容器启动；否则业务容器等待mysql启动。
3、container：业务容器
业务容器就是我们创建的pod资源内的容器服务，业务容器也叫APP容器，并行启动
镜像拉取策略（image PullPolicy）
有三种
- IfNotPresent：默认值，镜像在宿主机上不存在时才拉取
- Always：每次创建 Pod 都会重新拉取一次镜像
- Never： Pod 永远不会主动拉取这个镜像
查看镜像拉取策略
master 节点
[root@localhost bin]# kubectl get deploy/http-deployment -o yaml |grep imagePull imagePullPolicy: Always编辑一个pod并指定拉去策略
[root@localhost /]# mkdir beta1
[root@localhost /]# cd beta1/
[root@localhost beta1]# cat > Gself.yaml <<EOF
> apiVersion: v1
> kind: Pod
> metadata:
> name: gselfpod
> spec:
> containers:
> - name: nginx
> image: nginx:1.19
> imagePullPolicy: IfNotPresent
> EOF
[root@localhost beta1]# cat Gself.yaml
apiVersion: v1
kind: Pod
metadata:
name: GselfPod
spec:
containers:
- name: nginx
image: nginx:1.19
imagePullPolicy: ifnotpresent
command: ["echo","Success"]
[root@localhost beta1]# kubectl create -f Gself.yaml
pod/gselfpod created查看状态
[root@localhost beta1]# kubectl get pods
NAME READY STATUS RESTARTS AGE
gselfpod 0/1 CrashLoopBackOff 1 9s
http-deployment-766c5bfc5c-9x4c4 1/1 Running 0 7h38m
http-deployment-766c5bfc5c-ctmnk 1/1 Running 0 7h38m
http-deployment-766c5bfc5c-dkjgk 1/1 Running 0 7h38m失败的状态的原因是因为命令启动冲突
删除 command: [ “echo”, “SUCCESS” ]
[root@localhost beta1]# vim Gself.yaml
[root@localhost beta1]# cat Gself.yaml
apiVersion: v1
kind: Pod
metadata:
name: gselfpod
spec:
containers:
- name: nginx
image: nginx:1.19
imagePullPolicy: IfNotPresent
[root@localhost beta1]# kubectl apply -f Gself.yaml
pod/gselfpod created
[root@localhost beta1]# kubectl describe pod gselfpod
Name: gselfpod
Namespace: default
Priority: 0
PriorityClassName: <none>
Node: 20.0.0.4/20.0.0.4
Start Time: Mon, 12 Oct 2020 17:32:19 +0800
Labels: <none>
Annotations: kubectl.kubernetes.io/last-applied-configuration:
{"apiVersion":"v1","kind":"Pod","metadata":{"annotations":{},"name":"gselfpod","namespace":"default"},"spec":{"containers":[{"image":"ngin...
Status: Running
IP: 172.17.13.4
[root@localhost beta1]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE
gselfpod 1/1 Running 0 40s 172.17.13.4 20.0.0.4 <none>
http-deployment-766c5bfc5c-9x4c4 1/1 Running 0 7h48m 172.17.13.3 20.0.0.4 <none>
http-deployment-766c5bfc5c-ctmnk 1/1 Running 0 7h48m 172.17.54.2 20.0.0.5 <none>
http-deployment-766c5bfc5c-dkjgk 1/1 Running 0 7h48m 172.17.54.3 20.0.0.5 <none>去 20.0.0.4 节点，查看数据报头
[root@localhost docker]# curl -I 172.17.13.4 ##大写i
HTTP/1.1 200 OK
Server: nginx/1.19.3
Date: Mon, 12 Oct 2020 09:35:38 GMT
Content-Type: text/html
Content-Length: 612
Last-Modified: Tue, 29 Sep 2020 14:12:31 GMT
Connection: keep-alive
ETag: "5f7340cf-264"
Accept-Ranges: bytesK8s私有harbor仓库部署
安装docker-ce，docker-compose以及他们的依赖环境还要harbor
[root@harbor ~]# yum -y install yum-utils device-mapper-persistent-data lvm2 ##安装依赖
[root@harbor ~]# yum-config-manager --add-repo https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo ##安装阿里云docker镜像
已加载插件：fastestmirror, langpacks
adding repo from: https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
grabbing file https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo to /etc/yum.repos.d/docker-ce.repo
repo saved to /etc/yum.repos.d/docker-ce.repo
[root@harbor ~]# ll /etc/yum.repos.d/
总用量 36
-rw-r--r--. 1 root root 1664 11月 23 2018 CentOS-Base.repo
-rw-r--r--. 1 root root 1309 11月 23 2018 CentOS-CR.repo
-rw-r--r--. 1 root root 649 11月 23 2018 CentOS-Debuginfo.repo
-rw-r--r--. 1 root root 314 11月 23 2018 CentOS-fasttrack.repo
-rw-r--r--. 1 root root 630 11月 23 2018 CentOS-Media.repo
-rw-r--r--. 1 root root 1331 11月 23 2018 CentOS-Sources.repo
-rw-r--r--. 1 root root 5701 11月 23 2018 CentOS-Vault.repo
-rw-r--r--. 1 root root 2640 3月 16 2020 docker-ce.repo
[root@harbor ~]# yum -y install docker-ce
[root@harbor ~]# systemctl start docker下一步是镜像加速，自己去阿里云设置吧
[root@harbor ~]# systemctl daemon-reload
[root@harbor ~]# systemctl restart docker安装docker-compose
[root@harbor ~]# rz -E
rz waiting to receive.
[root@harbor ~]# ls
anaconda-ks.cfg initial-setup-ks.cfg 模板 图片 下载 桌面
docker-compose 公共 视频 文档 音乐
[root@harbor ~]# mv docker-compose /usr/local/bin/docker-compose
[root@harbor ~]# chmod +x /usr/local/bin/docker-compose
[root@harbor ~]# docker-compose -v
docker-compose version 1.21.1, build 5a3f1a3安装harbor
[root@harbor ~]# mkdir /harbor
[root@harbor ~]# cd /harbor/
[root@harbor harbor]# rz -E
rz waiting to receive.
[root@harbor harbor]# tar zxvf harbor-offline-installer-v1.2.2.tgz
[root@harbor harbor]# cd harbor/
[root@harbor harbor]# ls
common docker-compose.yml harbor.v1.2.2.tar.gz NOTICE
docker-compose.clair.yml harbor_1_1_0_template install.sh prepare
docker-compose.notary.yml harbor.cfg LICENSE upgrade
[root@harbor harbor]# vim harbor.cfg
hostname = 20.0.0.12
[root@harbor harbor]# sh install.sh
设置全部node节点的deamon-json文件，指定私仓地址
[root@localhost /]# vim /etc/docker/daemon.json
{
"registry-mirrors": ["https://*******.mirror.aliyuncs.com"],
"insecure-registries":["20.0.0.12"]
}
[root@localhost /]# systemctl daemon-reload
[root@localhost /]# systemctl restart docker
[root@5centos ~]# docker login -u admin -p Harbor12345 http://20.0.0.12
WARNING! Using --password via the CLI is insecure. Use --password-stdin.
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store
Login Succeeded下载tomcat镜像，并上载给harbor
[root@localhost /]# docker pull dordoka/tomcat
Using default tag: latest
latest: Pulling from dordoka/tomcat
e082d4499130: Pull complete
371450624c9e: Pull complete
c8a555b3a57c: Pull complete
1456d810d42e: Pull complete
1934ab037d50: Pull complete
297b1bee5293: Pull complete
d33229998f09: Pull complete
a18a39d0e788: Pull complete
8bcdb23cee94: Pull complete
cd68c521fa95: Pull complete
Digest: sha256:711b24da0a43f461d0a21d6348794880207d783e3c89cc761af34543de7912a3
Status: Downloaded newer image for dordoka/tomcat:latest
docker.io/dordoka/tomcat:latest上传给私库
[root@localhost /]# docker tag dordoka/tomcat:latest 20.0.0.12/beta01/tomcat
[root@localhost /]# docker push 20.0.0.12/beta01/tomcat
The push refers to repository [20.0.0.12/beta01/tomcat]
ea9c5326a600: Pushed
0eb88e292f51: Pushed
bfaffd009606: Pushed
0e17934bdc74: Pushed
c2476938351f: Pushed
6e0734ca81cd: Pushed
5f96fa66dc12: Pushed
dda5ec330bd9: Pushed
11a0c2f551fd: Pushed
eef560b4ec4f: Pushed
latest: digest: sha256:711b24da0a43f461d0a21d6348794880207d783e3c89cc761af34543de7912a3 size: 2412
下载测试
[root@localhost /]# docker rmi 20.0.0.12/beta01/tomcat:latest
Untagged: 20.0.0.12/beta01/tomcat:latest
Untagged: 20.0.0.12/beta01/tomcat@sha256:711b24da0a43f461d0a21d6348794880207d783e3c89cc761af34543de7912a3
[root@localhost /]# docker pull 20.0.0.12/beta01/tomcat
Using default tag: latest
latest: Pulling from beta01/tomcat
Digest: sha256:711b24da0a43f461d0a21d6348794880207d783e3c89cc761af34543de7912a3
Status: Downloaded newer image for 20.0.0.12/beta01/tomcat:latest
20.0.0.12/beta01/tomcat:latestmaster节点创建一个yaml文件并将镜像下载地址修改为harbor
[root@localhost beta1]# vim tomcat.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: mytomcat
spec:
replicas: 2
template:
metadata:
labels:
app: mytomcat
spec:
imagePullSecrets:
- name: registry-pull-secret
containers:
-name: mytomcat
image: 20.0.0.12/beta01/tomcat
imagePullPolicy: IfNotPresent ##如果我不指明拉去策略，我镜像就一直报错，就很烦
ports:
- containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: mytomcat
spec:
type: NodePort
ports:
- port: 80
targetPort: 80
nodePort: 30800
selector:
app: mytomcat
[root@localhost beta1]# kubectl apply -f tomcat.yaml
deployment.extensions/mytomcat unchanged
service/mytomcat created
[root@localhost beta1]# kubectl get pods
NAME READY STATUS RESTARTS AGE
http-deployment-766c5bfc5c-ctmnk 1/1 Running 1 14h
http-deployment-766c5bfc5c-dkjgk 1/1 Running 1 14h
http-deployment-766c5bfc5c-ttpt6 1/1 Running 0 4h51m
mytomcat-59bc9fdc84-7db4p 1/1 Running 0 3s
mytomcat-59bc9fdc84-cvd8r 1/1 Running 0 3s看到镜像被多下载了两次，这就差不多OK了
强制删除镜像方法
如果遇到处于Terminating状态的无法删除的容器可以强制删除
[root@master test]# kubectl get pods
NAME READY STATUS RESTARTS AGE
my-nginx-57667b9d9-nklvj 1/1 Terminating 0 10h
my-nginx-57667b9d9-wllnp 1/1 Terminating 0 10h
这种情况下可以使用强制删除命令
[root@master test]# kubectl delete pod my-nginx-57667b9d9-nklvj --force --grace-period=0 -n default
使用kubectl get ns，查看命名空间
[root@master test]# kubectl get ns
NAME STATUS AGE
default Active 12d
kube-public Active 12d
kube-system Active 12d
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