一、 K8S 架构
除了核心组件，还有一些推荐的 Add-ons：
| 组件名称 | 说明 |
|---|---|
| kube-dns | 负责为整个集群提供 DNS 服务 |
| Ingress Controller | 为服务提供外网入口 |
| Heapster | 提供资源监控 |
| Dashboard | 提供 GUI |
| Federation | 提供跨可用区的集群 |
| Fluentd-elasticsearch | 提供集群日志采集、存储与查询 |
K8S 核心功能：
-
自愈: 重新启动失败的容器，在节点不可用时，替换和重新调度节点上的容器，对用户定义的健康检查不响应的容器会被中止，并且在容器准备好服务之前不会把其向客户端广播。
-
弹性伸缩: 通过监控容器的 cpu 的负载值,如果这个平均高于 80%,增加容器的数量,如果这个平均低于 10%,减少容器的数量
-
服务的自动发现和负载均衡: 不需要修改您的应用程序来使用不熟悉的服务发现机制，Kubernetes 为容器提供了自己的 IP 地址和一组容器的单个 DNS 名称，并可以在它们之间进行负载均衡。
-
滚动升级和一键回滚: Kubernetes 逐渐部署对应用程序或其配置的更改，同时监视应用程序运行状况，以确保它不会同时终止所有实例。 如果出现问题，Kubernetes 会为您恢复更改，利用日益增长的部署解决方案的生态系统。
1.1 环境准备
cat >> /etc/hosts <<EOF
10.0.0.202 master
10.0.0.215 etcd
10.0.0.197 node1
10.0.0.163 node2
EOF
1.2 etcd 节点安装
[root@etcd ~]# yum install etcd -y
vim /etc/etcd/etcd.conf
6行：ETCD_LISTEN_CLIENT_URLS="http://0.0.0.0:2379"
21行：ETCD_ADVERTISE_CLIENT_URLS="http://10.0.0.215:2379"
systemctl start etcd.service
systemctl enable etcd.service
[root@etcd ~]# etcdctl -C http://10.0.0.215:2379 cluster-health
member 8e9e05c52164694d is healthy: got healthy result from http://10.0.0.215:2379
cluster is healthy
1.3 master 节点安装：
yum install kubernetes-master.x86_64 -y
vim /etc/kubernetes/apiserver
8行: KUBE_API_ADDRESS="--insecure-bind-address=0.0.0.0"
11行：KUBE_API_PORT="--port=8080"
17行：KUBE_ETCD_SERVERS="--etcd-servers=http://10.0.0.215:2379"
23行：KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ResourceQuota"
vim /etc/kubernetes/config
22行：KUBE_MASTER="--master=http://10.0.0.202:8080"
systemctl enable kube-apiserver.service
systemctl restart kube-apiserver.service
systemctl enable kube-controller-manager.service
systemctl restart kube-controller-manager.service
systemctl enable kube-scheduler.service
systemctl restart kube-scheduler.service
检查服务是否正常
[root@master ~]# kubectl get componentstatus
NAME STATUS MESSAGE ERROR
scheduler Healthy ok
controller-manager Healthy ok
etcd-0 Healthy {"health":"true"}
1.3 node 节点安装
yum install kubernetes-node.x86_64 -y
vim /etc/kubernetes/config
22行：KUBE_MASTER="--master=http://10.0.0.202:8080"
vim /etc/kubernetes/kubelet
5行：KUBELET_ADDRESS="--address=0.0.0.0"
8行：KUBELET_PORT="--port=10250"
11行：KUBELET_HOSTNAME="--hostname-override=10.0.0.163" #node节点ip
14行：KUBELET_API_SERVER="--api-servers=http://10.0.0.202:8080"
17行：KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=10.0.0.202:5000/rhel7/pod-infrastructure:latest" #这里需要把pod-infrastructure镜像做到本地镜像仓库
systemctl enable kubelet.service
systemctl restart kubelet.service
systemctl enable kube-proxy.service
systemctl restart kube-proxy.service
在 master 节点检查
[root@master ~]# kubectl get node
NAME STATUS AGE
10.0.0.163 Ready 1d
10.0.0.197 Ready 1d
1.4 所有节点配置 flannel 网络
yum install flannel -y
sed -i 's#http://127.0.0.1:2379#http://10.0.0.215:2379#g' /etc/sysconfig/flanneld
##etcd节点：
etcdctl mk /atomic.io/network/config '{ "Network": "172.18.0.0/16" }'
##master节点
yum install docker -y
systemctl enable flanneld.service
systemctl restart flanneld.service
service docker restart
systemctl restart kube-apiserver.service
systemctl restart kube-controller-manager.service
systemctl restart kube-scheduler.service
##node节点：
systemctl enable flanneld.service
systemctl restart flanneld.service
service docker restart
systemctl restart kubelet.service
systemctl restart kube-proxy.service
vim /usr/lib/systemd/system/docker.service
#在[Service]区域下增加一行
ExecStartPost=/usr/sbin/iptables -P FORWARD ACCEPT
systemctl daemon-reload
systemctl restart docker
1.5 配置 master 为镜像仓库
#所有节点
vim /etc/sysconfig/docker
OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false --registry-mirror=https://registry.docker-cn.com --insecure-registry=10.0.0.202:5000'
systemctl restart docker
#master节点（如有网络问题，多试几次）
docker run -d -p 5000:5000 --restart=always --name registry -v /opt/myregistry:/var/lib/registry registry
二、 K8S 常用资源
2.1 pod 资源
pod 是最小资源单位.
k8s yaml 的主要组成
apiVersion: v1 api版本
kind: pod 资源类型
metadata: 属性
spec: 详细
- 创建一个 yaml 文件：
[root@master pod]# cat k8s_pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx
labels:
app: web
spec:
containers:
- name: nginx
image: 10.0.0.202:5000/nginx:latest
ports:
- containerPort: 80
基于 yaml 创建 pod：
[root@master pod]# kubectl create -f k8s_pod.yaml
pod "nginx1" created
[root@master pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx 0/1 ContainerCreating 0 12s
此时发现 pod 创建没能成功，通过
kubectl describe pod nginx查看详细信息：
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
2m 2m 1 {default-scheduler } Normal Scheduled Successfully assigned nginx to 10.0.0.197
2m 43s 4 {kubelet 10.0.0.197} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request. details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"
1m 6s 6 {kubelet 10.0.0.197} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""
由上可见，需要本地镜像仓库需要 pod-infrastructure:latest 这个 pod 基础镜像，所以需要在拉取镜像
docker pull tianyebj/pod-infrastructure，并且 push 到本地镜像仓库
docker pull tianyebj/pod-infrastructure
docker tag docker.io/tianyebj/pod-infrastructure 10.0.0.202:5000/rhel7/pod-infrastructure:latest
docker push 10.0.0.202:5000/rhel7/pod-infrastructure:latest
#同时改下node节点： /etc/kubernetes/kubelet
#更改配置：KUBELET_POD_INFRA_CONTAINER="--pod-infra-container-image=10.0.0.202:5000/rhel7/pod-infrastructure:latest"
systemctl restart kubelet.service
在此查看 pod 创建过程：
Events:
FirstSeen LastSeen Count From SubObjectPath Type Reason Message
--------- -------- ----- ---- ------------- -------- ------ -------
14m 14m 1 {default-scheduler } Normal Scheduled Successfully assigned nginx to 10.0.0.197
13m 3m 7 {kubelet 10.0.0.197} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ErrImagePull: "image pull failed for registry.access.redhat.com/rhel7/pod-infrastructure:latest, this may be because there are no credentials on this request. details: (open /etc/docker/certs.d/registry.access.redhat.com/redhat-ca.crt: no such file or directory)"
13m 58s 54 {kubelet 10.0.0.197} Warning FailedSync Error syncing pod, skipping: failed to "StartContainer" for "POD" with ImagePullBackOff: "Back-off pulling image \"registry.access.redhat.com/rhel7/pod-infrastructure:latest\""
45s 45s 1 {kubelet 10.0.0.197} spec.containers{nginx} Normal Pulling pulling image "10.0.0.202:5000/nginx:1.13"
46s 41s 2 {kubelet 10.0.0.197} Warning MissingClusterDNS kubelet does not have ClusterDNS IP configured and cannot create Pod using "ClusterFirst" policy. Falling back to DNSDefault policy.
41s 41s 1 {kubelet 10.0.0.197} spec.containers{nginx} Normal Pulled Successfully pulled image "10.0.0.202:5000/nginx:1.13"
41s 41s 1 {kubelet 10.0.0.197} spec.containers{nginx} Normal Created Created container with docker id 9254a49fc62c; Security:[seccomp=unconfined]
41s 41s 1 {kubelet 10.0.0.197} spec.containers{nginx} Normal Started Started container with docker id 9254a49fc62c
到此 pod 创建完成
详细
在这里需要把 pod 容器 tag 改成需要用的：
[root@master pod]# docker tag docker.io/tianyebj/pod-infrastructure 10.0.0.202:5000/rhel7/pod-infrastructure:latest
[root@master pod]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/registry latest f32a97de94e1 9 months ago 25.8 MB
docker.io/tianyebj/pod-infrastructure latest 34d3450d733b 2 years ago 205 MB
10.0.0.202:5000/rhel7/pod-infrastructure latest 34d3450d733b 2 years ago 205 MB
强制删除 pod 资源：
[root@master pod]# kubectl delete pod nginx --force --grace-period=0 -n default
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 "nginx" deleted
安装 docker 镜像并且 push 到本地镜像仓库
[root@master pod]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/b3log/solo latest 4e49320bec76 2 days ago 152 MB
10.0.0.202:5000/b3log/solo latest 4e49320bec76 2 days ago 152 MB
docker.io/mysql 5.7 1e4405fe1ea9 2 weeks ago 437 MB
10.0.0.202:5000/nginx latest 231d40e811cd 2 weeks ago 126 MB
docker.io/nginx latest 231d40e811cd 2 weeks ago 126 MB
docker.io/registry latest f32a97de94e1 9 months ago 25.8 MB
10.0.0.202:5000/rhel7/pod-infrastructure latest 34d3450d733b 2 years ago 205 MB
docker.io/tianyebj/pod-infrastructure latest 34d3450d733b 2 years ago 205 MB
[root@master pod]# docker tag docker.io/nginx 10.0.0.202:5000/nginx:latest
[root@master pod]# docker push 10.0.0.202:5000/nginx
[root@master pod]# docker tag docker.io/mysql:5.7 10.0.0.202:5000/mysql:5.7
[root@master pod]# docker push 10.0.0.202:5000/mysql
创建 pod
[root@master pod]# kubectl create -f k8s_pod.yaml
pod "nginx" created
[root@master pod]# kubectl get pod
NAME READY STATUS RESTARTS AGE
nginx 1/1 Running 0 7s
pod 运行多个容器：
[root@master pod]# cat k8s_pod2.yaml
apiVersion: v1
kind: Pod
metadata:
name: test
labels:
app: web
spec:
containers:
- name: nginx
image: 10.0.0.202:5000/nginx:latest
ports:
- containerPort: 80
- name: solo
image: 10.0.0.202:5000/b3log/solo:latest
command: ["sleep","10000"]
[root@master pod]# kubectl create -f k8s_pod2.yaml
pod "test" created
[root@master pod]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE
nginx 1/1 Running 0 15h 172.18.57.2 10.0.0.197
test 2/2 Running 0 15s 172.18.39.2 10.0.0.163
查看 k8s pod 的容器资源详细信息：
docker inspect 3f6cdafa32f5
创建一个 pod 资源，才能实现 k8s 的高级功能.
pod 容器：基础架构容器
nginx 容器： 业务容器
[root@node1 ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
3f6cdafa32f5 10.0.0.202:5000/nginx:latest "nginx -g 'daemon ..." 17 hours ago Up 17 hours k8s_nginx.c74a033c_nginx_default_e5a7a5ea-1bf8-11ea-950d-fa163ef9cf10_5e72b386
d0198f64f479 10.0.0.202:5000/rhel7/pod-infrastructure:latest "/pod" 17 hours ago Up 17 hours k8s_POD.7b6a03f3_nginx_default_e5a7a5ea-1bf8-11ea-950d-fa163ef9cf10_7ee05d13
2.2 ReplicationController 资源
k8s 资源的常见操作:
kubectl create -f xxx.yaml
kubectl get pod|rc
kubectl describe pod nginx
kubectl delete pod nginx 或者 kubectl delete -f xxx.yaml
kubectl edit pod nginx
rc:保证指定数量的 pod 始终存活,rc 通过标签选择器来关联 pod
POD 资源被关闭也会及时启动自愈。
rc 资源
pod 资源的高可用行
[root@node2 ~]# docker ps -a -q
f14a9650d408
5a4a70671124
[root@node2 ~]# docker rm -f `docker ps -a -q`
f14a9650d408
5a4a70671124
[root@node2 ~]# docker ps -a -q
7f4142ea7eb9
2ec639b32132
pod 资源被强制删除停止后，这些资源会立即重新生成并启动。
rc 创建
rc:保证指定数量的 pod 始终够存活，rc 通过标签选择器来关联 pod
- 创建 yaml 文件
[root@master rc]# cat k8s_rc.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: nginx
spec:
replicas: 5
selector:
app: myweb
template:
metadata:
labels:
app: myweb
spec:
containers:
- name: myweb
image: 10.0.0.202:5000/nginx:1.13
ports:
- containerPort: 80
- 创建 rc：
[root@master rc]# pwd
/root/k8s/rc
[root@master rc]# kubectl create -f k8s_rc.yaml
replicationcontroller "nginx" created
查看状态：
[root@master rc]# kubectl get rc
NAME DESIRED CURRENT READY AGE
nginx 5 5 5 9m
- 启动了多个 pod
rc 作用：
当 node 节点上的 pod 资源在其中一个 node 挂掉之后，rc 会将挂掉的 node 上的 pod 资源驱逐到存活的 node 之上。
示例 1：
pod 资源删除后，会马上重新创建新的 pod。
[root@master rc]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE
nginx 1/1 Running 0 3d 172.18.42.2 10.0.0.197
nginx-0lrwh 1/1 Running 0 37m 172.18.96.4 10.0.0.163
nginx-7wss6 1/1 Running 0 37m 172.18.42.4 10.0.0.197
nginx-g3pnd 1/1 Running 0 37m 172.18.96.3 10.0.0.163
nginx-j173g 1/1 Running 0 37m 172.18.96.5 10.0.0.163
nginx-pxlbx 1/1 Running 0 37m 172.18.42.5 10.0.0.197
nginxmysql 2/2 Running 0 1h 172.18.42.3 10.0.0.197
test 1/1 Running 0 1h 172.18.96.2 10.0.0.163
[root@master rc]# kubectl delete pod nginx-7wss6
pod "nginx-7wss6" deleted
[root@master rc]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE
nginx 1/1 Running 0 3d 172.18.42.2 10.0.0.197
nginx-0lrwh 1/1 Running 0 38m 172.18.96.4 10.0.0.163
nginx-g3pnd 1/1 Running 0 38m 172.18.96.3 10.0.0.163
nginx-j173g 1/1 Running 0 38m 172.18.96.5 10.0.0.163
nginx-j7jrw 1/1 Running 0 3s 172.18.42.6 10.0.0.197
nginx-pxlbx 1/1 Running 0 38m 172.18.42.5 10.0.0.197
nginxmysql 2/2 Running 0 1h 172.18.42.3 10.0.0.197
test 1/1 Running 0 1h 172.18.96.2 10.0.0.163
- 示例 2：把 node2 删掉，会出现如下现象
[root@master rc]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE
nginx 1/1 Running 0 3d 172.18.42.2 10.0.0.197
nginx-0lrwh 1/1 Running 0 3h 172.18.96.4 10.0.0.163
nginx-g3pnd 1/1 Running 0 3h 172.18.96.3 10.0.0.163
nginx-j173g 1/1 Running 0 3h 172.18.96.5 10.0.0.163
nginx-j7jrw 1/1 Running 0 2h 172.18.42.6 10.0.0.197
nginx-pxlbx 1/1 Running 0 3h 172.18.42.5 10.0.0.197
nginxmysql 2/2 Running 1 3h 172.18.42.3 10.0.0.197
test 1/1 Running 0 3h 172.18.96.2 10.0.0.163
[root@master rc]# kubectl delete node 10.0.0.163
node "10.0.0.163" deleted
[root@master rc]# kubectl get pod -o wide
NAME READY STATUS RESTARTS AGE IP NODE
nginx 1/1 Running 0 3d 172.18.42.2 10.0.0.197
nginx-fl07j 1/1 Running 0 2s 172.18.42.7 10.0.0.197
nginx-j7jrw 1/1 Running 0 2h 172.18.42.6 10.0.0.197
nginx-jp6jg 1/1 Running 0 2s 172.18.42.4 10.0.0.197
nginx-pxlbx 1/1 Running 0 3h 172.18.42.5 10.0.0.197
nginx-zr9mw 1/1 Running 0 2s 172.18.42.8 10.0.0.197
nginxmysql 2/2 Running 1 3h 172.18.42.3 10.0.0.197
node2 的 kubelet 重启后会自动注册到集群
rc 是通过什么来关联 pod 的呢？
通过更改 [root@master rc]# kubectl edit pod nginx 同一标签为 myweb 后，默认会把 pod 存活年龄最小的剔除
所以 rc 的 pod 资源是有标签选择器来进行维护。
rc 滚动升级
- 版本升级：
[root@master rc]# kubectl rolling-update nginx -f k8s_rc1.yaml --update-period=10s
--update-period=10s：升级间隔 10s
找一个 pod 容器进行 nginx 版本测试
升级成功
- 版本回滚：
[root@master rc]# kubectl rolling-update nginx2 -f k8s_rc.yaml --update-period=1s
版本测试：
- 升级回滚配置文件：
最后总结一下 RC（Replica Set）的一些特性与作用。
◎ 在大多数情况下，我们通过定义一个 RC 实现 Pod 的创建及副本数量的自动控制。
◎ 在 RC 里包括完整的 Pod 定义模板。
◎ RC 通过 Label Selector 机制实现对 Pod 副本的自动控制。
◎ 通过改变 RC 里的 Pod 副本数量，可以实现 Pod 的扩容或缩容。
◎ 通过改变 RC 里 Pod 模板中的镜像版本，可以实现 Pod 的滚动升级。
2.3 service 资源
service 帮助 pod 暴露端口，通过架构图看出通过任何服务可通过 kube-proxy 组件进行通信。
创建一个 service
[root@master svc]# cat k8s_svc.yaml
apiVersion: v1
kind: Service
metadata:
name: myweb
spec:
type: NodePort #ClusterIP
ports:
- port: 80 #clusterIP
nodePort: 30000 #node port
targetPort: 80 #pod port
selector:
app: myweb2
[root@master svc]# kubectl create -f k8s_svc.yaml
注意：
svc 标签选择器和 rc 的标签需要一致，不然访问不了后端服务。
通过：[root@master svc]# kubectl edit svc myweb 修改标签和 rc 标签一致。
- 再次查看：
-
并且现在和 pod 的 ip 相对应
-
查看 node 服务 L:
-
测试服务：
测试负载均衡
- 减少 pod 节点进行测试
[root@master svc]# kubectl scale rc nginx --replicas=2
调整副本数量的命令
- 进入容器修改 index 页面
[root@master svc]# kubectl exec -it nginx-175x8 /bin/bash
root@nginx-175x8:/# cd /usr/share/nginx/html/
root@nginx-175x8:/usr/share/nginx/html# ls
50x.html index.html
root@nginx-175x8:/usr/share/nginx/html# echo 'cuijianzhe' > index.html
测试：
- 默认端口范围是 30000-32767
修改 ports 端口数量：
[root@master svc]# vim /etc/kubernetes/apiserver
KUBE_API_ARGS="--service-node-port-range=3000-50000"
[root@master svc]# systemctl restart kube-apiserver
- 添加 svc 3000 端口
[root@master svc]# cat k8s_svc2.yaml
apiVersion: v1
kind: Service
metadata:
name: myweb2
spec:
type: NodePort #ClusterIP
ports:
- port: 80 #clusterIP
nodePort: 3000 #node port
targetPort: 80 #pod port
selector:
app: myweb2
修改 svc 统一标签 myweb
kubectl edit svc myweb
[root@master svc]# kubectl get svc -o wide
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR
kubernetes 10.254.0.1 <none> 443/TCP 3d <none>
myweb 10.254.134.169 <nodes> 80:30000/TCP 55m app=myweb
myweb2 10.254.55.214 <nodes> 80:3000/TCP 2m app=myweb
通过一条命令添加 service 资源
kubectl scale rc nginx --replicas=2
kubectl exec -it pod_name /bin/bash
kubectl expose rc nginx --type=NodePort --port=80
2.4 deployment 资源
有 rc 在滚动升级之后,会造成服务访问中断,于是 k8s 引入了 deployment 资源
- 创建 deployment
[root@master deploy]# cat k8s_deploy.yaml
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 3
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: 10.0.0.202:5000/nginx:1.13
ports:
- containerPort: 80
resources:
limits:
cpu: 100m
requests:
cpu: 100m
[root@master deploy]# kubectl create -f k8s_deploy.yaml
deployment "nginx-deployment" created
[root@master deploy]# kubectl get deploy
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
nginx-deployment 3 3 3 3 18s
给 deployment 分配端口，出现一个新的 svc：
[root@master deploy]# kubectl expose deployment nginx-deployment --type=NodePort --port=80
service "nginx-deployment" exposed
[root@master deploy]# kubectl get svc
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes 10.254.0.1 <none> 443/TCP 3d
myweb 10.254.134.169 <nodes> 80:30000/TCP 17h
myweb2 10.254.55.214 <nodes> 80:3000/TCP 16h
nginx-deployment 10.254.2.186 <nodes> 80:33604/TCP 13s
通过 curl 测试：
滚动升级：
更改 [root@master deploy]# kubectl edit deployment nginx-deployment 配置文件
[root@master deploy]# kubectl edit deployment nginx-deployment
#将 - image: 10.0.0.202:5000/nginx:1.13 改为
- image: 10.0.0.202:5000/nginx:latest
curl 测试升级完成：
升级策略
[root@master deploy]# kubectl edit deployment nginx-deployment
...
strategy:
rollingUpdate:
maxSurge: 1
maxUnavailable: 1
type: RollingUpdate
...
升级回滚
- 第一种
[root@master deploy]# kubectl rollout history deployment nginx-deployment
deployments "nginx-deployment"
REVISION CHANGE-CAUSE
2 <none>
3 <none>
[root@master deploy]# kubectl rollout undo deployment nginx-deployment
deployment "nginx-deployment" rolled back
[root@master deploy]# kubectl rollout history deployment nginx-deployment
deployments "nginx-deployment"
REVISION CHANGE-CAUSE
3 <none>
4 <none>
回滚之后版本：
指定回滚版本号：
[root@master deploy]# kubectl rollout undo deployment nginx-deployment --to-revision=4
deployment "nginx-deployment" rolled back
- 第二种：因为第一种版本号镜像版本没有详细版本，删除 deplotment 用命令行启动 deployment，再次查看会发现具体到相关镜像版本号等信息
[root@master deploy]# kubectl delete deployment nginx-deployment
deployment "nginx-deployment" deleted
[root@master deploy]# kubectl rollout history deployment nginx
deployments "nginx"
REVISION CHANGE-CAUSE
1 kubectl run nginx --image=10.0.0.202:5000/nginx:1.13 --replicas=3 --record
升级版本
[root@master deploy]# kubectl set image deployment nginx nginx=10.0.0.202:5000/nginx:1.16
deployment "nginx" image updated
[root@master deploy]# kubectl rollout history deployment nginx
deployments "nginx"
REVISION CHANGE-CAUSE
1 kubectl run nginx --image=10.0.0.202:5000/nginx:1.13 --replicas=3 --record
2 kubectl edit deployment nginx
3 kubectl set image deployment nginx nginx=10.0.0.202:5000/nginx:1.16
[root@master deploy]# kubectl set image deployment nginx nginx=10.0.0.202:5000/nginx:latest
deployment "nginx" image updated
[root@master deploy]# kubectl rollout history deployment nginx
deployments "nginx"
REVISION CHANGE-CAUSE
1 kubectl run nginx --image=10.0.0.202:5000/nginx:1.13 --replicas=3 --record
3 kubectl set image deployment nginx nginx=10.0.0.202:5000/nginx:1.16
4 kubectl set image deployment nginx nginx=10.0.0.202:5000/nginx:latest
deployment 升级和回滚
命令行创建 deployment
kubectl run nginx --image=10.0.0.202:5000/nginx:1.13 --replicas=3 --record
命令行升级版本
kubectl set image deploy nginx nginx=10.0.0.202:5000/nginx:1.15
查看 deployment 所有历史版本
kubectl rollout history deployment nginx
deployment 回滚到上一个版本
kubectl rollout undo deployment nginx
deployment 回滚到指定版本
kubectl rollout undo deployment nginx --to-revision=2
三、 Tomcat+Mysql 练习
在 K8S 容器之间相互访问,通过 VIP 地址!
- 启动 Mysql yaml 配置文件，创建 Rc 资源
[root@master tomcat_demo]# cat mysql-rc.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: mysql
spec:
replicas: 1
selector:
app: mysql
template:
metadata:
labels:
app: mysql
spec:
containers:
- name: mysql
image: 10.0.0.202:5000/mysql:5.7
ports:
- containerPort: 3306
env:
- name: MYSQL_ROOT_PASSWORD
value: '598941324'
[root@master tomcat_demo]# kubectl create -f mysql-rc.yaml
replicationcontroller "mysql" created
2.创建 Mysql-svc yaml 配置文件，创建 Service 资源
[root@master tomcat_demo]# cat mysql-svc.yaml
apiVersion: v1
kind: Service
metadata:
name: mysql
spec:
# type: NodePort #ClusterIP
ports:
- port: 3306
targetPort: 3306 #pod port
selector:
app: mysql
[root@master tomcat_demo]# kubectl create -f mysql-svc.yaml
service "mysql" created
[root@master tomcat_demo]# kubectl get svc
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes 10.254.0.1 <none> 443/TCP 4d
mysql 10.254.76.200 <none> 3306/TCP 1m
myweb 10.254.134.169 <nodes> 80:30000/TCP 1d
myweb2 10.254.55.214 <nodes> 80:3000/TCP 1d
nginx-deployment 10.254.2.186 <nodes> 80:33604/TCP 1d
- Tomcat yaml 配置文件，创建 Tomcat Rc 资源
[root@master tomcat_demo]# cat tomcat-rc.yaml
apiVersion: v1
kind: ReplicationController
metadata:
name: tomcat
spec:
replicas: 1
selector:
app: tomcat
template:
metadata:
labels:
app: tomcat
spec:
containers:
- name: tomcat
image: 10.0.0.202:5000/tomcat:latest
ports:
- containerPort: 8080
env:
- name: MYSQL_SERVICE_HOST
value: '10.254.76.200' #此处是上面查看svc的MySQL CLUSTER-IP
- name: MYSQL_SERVICE_PORT
value: '3306'
- 创建 tomcat-svc yaml 配置文件，启动 tomcat-svc 资源
[root@master tomcat_demo]# cat tomcat-svc.yaml
apiVersion: v1
kind: Service
metadata:
name: tomcat
spec:
type: NodePort #ClusterIP
ports:
- port: 8080 #clusterIP
nodePort: 30008 #node port
targetPort: 8080 #pod port
selector:
app: tomcat
[root@master tomcat_demo]# kubectl create -f tomcat-svc.yaml
service "tomcat" created
测试 tomcat 服务：
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