一 Deployment相对于RC的优势
RS与Deployment主要用于替代RC。RS的全称为Replica Set。相对于RC，RS与Deployment的优势如下：
- RC只支持基于等式的selector，如env=dev或者environment!=qa。但在RS中，还支持新的基于集合的selector，如version in (v1.0,v2.0)或者env not in (dev,qa)。这给复杂的运维管理带来方便
- 使用Deployment升级Pod只需要定义Pod的最终状态，k8s会为你执行必要的操作。虽然使用kubectl rolling-update也可以完成滚动升级，但它是在客户端与服务端多次交互控制RC完成的，所以REST API中并没有rolling-update的接口，这为定制自己的管理系统带来了一些麻烦。Deployment拥有更加灵活的升级、回滚功能。
Replica Set目前与RC的区别只是支持的selector不同，后续会加入更多的功能。Deployment使用了Replica Set，是更高一层的概念。除非需要自定义升级功能或者根本不需要升级Pod，否则还是建议使用Deployment而不直接使用Replica Set。
二 Deployment是简单使用
2.1 同时安装三个nginx pod
[root@docker-server1 manifests]# cd /yamls/
[root@docker-server1 yamls]# mkdir deployment
[root@docker-server1 yamls]# cd deployment
[root@docker-server1 deployment]# vim nginx-deployment.yaml
apiVersion: apps/v1 kind: Deployment metadata: name: hello-deployment namespace: default spec: replicas: 3 selector: matchLabels: name: hello-deployment strategy: type: RollingUpdate rollingUpdate: maxSurge: 10% maxUnavailable: 0 template: metadata: labels: name: hello-deployment spec: containers: - name: webserver image: nginx:1.4 ports: - containerPort: 80
[root@docker-server1 deployment]# kubectl apply -f nginx-deployment.yaml
2.2 查看
[root@docker-server1 deployment]# kubectl get pods
NAME READY STATUS RESTARTS AGE goproxy 1/1 Running 0 126m hello-deployment-c6fb6d858-9g5pq 0/1 ErrImagePull 0 11s hello-deployment-c6fb6d858-qnnld 0/1 ErrImagePull 0 11s hello-deployment-c6fb6d858-v549m 0/1 ErrImagePull 0 11s init-demo 1/1 Running 0 68m nginx 2/2 Running 4 4h13m nginx-volume 1/1 Running 0 88m
[root@docker-server1 deployment]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES goproxy 1/1 Running 0 126m 10.244.1.8 192.168.132.132 <none> <none> hello-deployment-c6fb6d858-9g5pq 0/1 ImagePullBackOff 0 21s 10.244.2.11 192.168.132.133 <none> <none> hello-deployment-c6fb6d858-qnnld 0/1 ImagePullBackOff 0 21s 10.244.1.12 192.168.132.132 <none> <none> hello-deployment-c6fb6d858-v549m 0/1 ImagePullBackOff 0 21s 10.244.1.13 192.168.132.132 <none> <none> init-demo 1/1 Running 0 68m 10.244.1.10 192.168.132.132 <none> <none> nginx 2/2 Running 4 4h14m 10.244.2.10 192.168.132.133 <none> <none> nginx-volume 1/1 Running 0 89m 10.244.1.9 192.168.132.132 <none> <none>
[root@docker-server1 deployment]# kubectl describle pods hello-deployment-c6fb6d858-v549m
Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled <unknown> default-scheduler Successfully assigned default/hello-deployment-c6fb6d858-v549m to 192.168.132.132 Normal Pulling 4m36s (x4 over 6m20s) kubelet, 192.168.132.132 Pulling image "nginx:1.4" Warning Failed 4m32s (x4 over 6m12s) kubelet, 192.168.132.132 Failed to pull image "nginx:1.4": rpc error: code = Unknown desc = Error response from daemon: manifest for nginx:1.4 not found: manifest unknown: manifest unknown Warning Failed 4m32s (x4 over 6m12s) kubelet, 192.168.132.132 Error: ErrImagePull Warning Failed 4m8s (x7 over 6m11s) kubelet, 192.168.132.132 Error: ImagePullBackOff Normal BackOff 74s (x19 over 6m11s) kubelet, 192.168.132.132 Back-off pulling image "nginx:1.4"
是nginx:1.4没有这个镜像
2.3 滚动更新
修改为1.14版本，就会自己更新
滚动更新策略
1 先删后起
2 先起后删
[root@docker-server1 deployment]# kubectl apply -f nginx-deployment.yaml
[root@docker-server1 deployment]# kubectl get pods -o wide
hello-deployment-5fdb46d67c-jvvjr 0/1 ContainerCreating 0 4s <none> 192.168.132.132 <none> <none> hello-deployment-c6fb6d858-9g5pq 0/1 ImagePullBackOff 0 8m15s 10.244.2.11 192.168.132.133 <none> <none> hello-deployment-c6fb6d858-qnnld 0/1 ImagePullBackOff 0 8m15s 10.244.1.12 192.168.132.132 <none> <none> hello-deployment-c6fb6d858-v549m 0/1 ImagePullBackOff 0 8m15s 10.244.1.13 192.168.132.132 <none> <none>
[root@docker-server1 deployment]# kubectl get pods -o wide
hello-deployment-5fdb46d67c-7ct2z 0/1 ContainerCreating 0 9s <none> 192.168.132.133 <none> <none> hello-deployment-5fdb46d67c-jvvjr 1/1 Running 0 34s 10.244.1.14 192.168.132.132 <none> <none> hello-deployment-c6fb6d858-9g5pq 0/1 ImagePullBackOff 0 8m45s 10.244.2.11 192.168.132.133 <none> <none> hello-deployment-c6fb6d858-qnnld 0/1 ImagePullBackOff 0 8m45s 10.244.1.12 192.168.132.132 <none> <none>
已经运行成功更新一个
[root@docker-server1 deployment]# kubectl get pods -o wide
hello-deployment-5fdb46d67c-7ct2z 1/1 Running 0 118s 10.244.2.12 192.168.132.133 <none> <none> hello-deployment-5fdb46d67c-jvvjr 1/1 Running 0 2m23s 10.244.1.14 192.168.132.132 <none> <none> hello-deployment-5fdb46d67c-qfjht 1/1 Running 0 90s 10.244.1.15 192.168.132.132 <none> <none
全部更新
二 部署一个word press网站
2.1 部署mysql
[root@docker-server1 deployment]# vim mysql-deployment.yaml
apiVersion: apps/v1 kind: Deployment metadata: name: mysql namespace: default spec: replicas: 1 selector: matchLabels: app: mysql template: metadata: labels: app: mysql spec: containers: - name: mysql image: mysql:5.7 ports: - containerPort: 3306 env: - name: MYSQL_ROOT_PASSWORD value: RedHat123 - name: MYSQL_DATABASE value: wordpress
[root@docker-server1 deployment]# kubectl apply -f mysql-deployment.yaml
[root@docker-server1 deployment]# kubectl get pods
mysql-5d4695cd5-kq9cl 0/1 ContainerCreating 0 8s
[root@docker-server1 deployment]# yum -y install mysql
[root@docker-server1 deployment]# kubectl get pods
NAME READY STATUS RESTARTS AGE
goproxy 1/1 Running 0 149m
hello-deployment-5fdb46d67c-7ct2z 1/1 Running 0 15m
hello-deployment-5fdb46d67c-jvvjr 1/1 Running 0 15m
hello-deployment-5fdb46d67c-qfjht 1/1 Running 0 14m
init-demo 1/1 Running 0 92m
mysql-5d4695cd5-kq9cl 1/1 Running 0 102s
nginx 2/2 Running 4 4h37m
nginx-volume 1/1 Running 0 112m
[root@docker-server1 deployment]# kubectl get pods -o wide
mysql-5d4695cd5-kq9cl 1/1 Running 0 3m22s 10.244.1.16 192.168.132.132
[root@docker-server1 deployment]# mysql -uroot -pRedHat123 -h10.244.1.16
2.2 部署wordpress
[root@docker-server1 deployment]# vi wordpress-deployment.yaml
apiVersion: apps/v1 kind: Deployment metadata: name: wordpress namespace: default spec: replicas: 1 selector: matchLabels: app: wordpress template: metadata: labels: app: wordpress spec: nodeName: 192.168.1.233 containers: - name: wordpress image: wordpress:5.3.2-php7.2-apache ports: - containerPort: 80 env: - name: WORDPRESS_DB_PASSWORD value: RedHat123 - name: WORDPRESS_DB_NAME value: wordpress - name: WORDPRESS_DB_HOST value: 10.244.1.16 - name: WORDPRESS_DB_USER value: root
[root@docker-server1 deployment]# kubectl apply -f wordpress-deployment.yaml
[root@docker-server1 deployment]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES goproxy 1/1 Running 0 164m 10.244.1.8 192.168.132.132 <none> <none> init-demo 1/1 Running 0 106m 10.244.1.10 192.168.132.132 <none> <none> mysql-5d4695cd5-kq9cl 1/1 Running 0 16m 10.244.1.16 192.168.132.132 <none> <none> nginx 2/2 Running 4 4h51m 10.244.2.10 192.168.132.133 <none> <none> nginx-volume 1/1 Running 0 127m 10.244.1.9 192.168.132.132 <none> <none> wordpress-86cbfc4456-zp985 0/1 ContainerCreating 0 2s <none> 192.168.132.131 <none> <none>
[root@docker-server1 deployment]# kubectl describe pods wordpress-86cbfc4456-zp985
Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Pulling 3m5s kubelet, 192.168.132.131 Pulling image "wordpress:5.3.2-php7.2-apache" Normal Pulled 97s kubelet, 192.168.132.131 Successfully pulled image "wordpress:5.3.2-php7.2-apache" Normal Created 94s kubelet, 192.168.132.131 Created container wordpress Normal Started 94s kubelet, 192.168.132.131 Started container wordpress
[root@docker-server1 deployment]# kubectl get pods -o wide
NAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATES goproxy 1/1 Running 0 167m 10.244.1.8 192.168.132.132 <none> <none> init-demo 1/1 Running 0 109m 10.244.1.10 192.168.132.132 <none> <none> mysql-5d4695cd5-kq9cl 1/1 Running 0 19m 10.244.1.16 192.168.132.132 <none> <none> nginx 2/2 Running 4 4h55m 10.244.2.10 192.168.132.133 <none> <none> nginx-volume 1/1 Running 0 130m 10.244.1.9 192.168.132.132 <none> <none> wordpress-86cbfc4456-zp985 1/1 Running 0 3m9s 10.244.0.4 192.168.132.131 <none> <none>
2.3 service资源对象创建MySQL的转发
负载均衡器对象，通过创建 service资源对象，会在ku即e- proxy上为这一类资源创建一个負载均衡器，并为其生成一个集群内部可访问的不变的VIP
[root@docker-server1 deployment]# mkdir /yamls/svcs
[root@docker-server1 deployment]# cd /yamls/svcs
[root@docker-server1 svcs]# vi mysql-svc.yaml
apiVersion: v1 kind: Service metadata: name: mysql-svc spec: selector: #匹配label app: mysql type: ClusterIP ports: - port: 3306 targetPort: 3306
[root@docker-server1 svcs]# kubectl apply -f mysql-svc.yaml
[root@docker-server1 svcs]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 10h mysql-svc ClusterIP 10.96.240.104 <none> 3306/TCP 18s
[root@docker-server1 svcs]# cat mysql-svc.yam
apiVersion: v1 kind: Service metadata: name: mysql-svc spec: selector: app: mysql type: ClusterIP clusterIP: 10.96.240.104 ports: - port: 3306 targetPort: 3306
[root@docker-server1 svcs]# kubectl delete -f mysql-svc.yaml
[root@docker-server1 svcs]# kubectl apply -f mysql-svc.yaml
[root@docker-server1 svcs]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 10h mysql-svc ClusterIP 10.96.240.104 <none> 3306/TCP 7s
[root@docker-server1 svcs]# mysql -uroot -pRedHat123 -h10.96.240.104
在这里连接很慢
[root@docker-server1 deployment]# kubectl get svc --all-namespaces
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE default kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 11h default mysql-svc ClusterIP 10.96.240.104 <none> 3306/TCP 9m37s kube-system kube-dns ClusterIP 10.96.0.10 <none> 53/UDP,53/TCP,9153/TCP 11h kubernetes-dashboard dashboard-metrics-scraper ClusterIP 10.96.93.119 <none> 8000/TCP 10h kubernetes-dashboard kubernetes-dashboard NodePort 10.96.87.98 <none> 443:32443/TCP 10h
2.4 修改wordspress
apiVersion: apps/v1 kind: Deployment metadata: name: wordpress namespace: default spec: replicas: 1 selector: matchLabels: app: wordpress template: metadata: labels: app: wordpress spec: nodeName: 192.168.132.131 containers: - name: wordpress image: wordpress:5.3.2-php7.2-apache ports: - containerPort: 80 env: - name: WORDPRESS_DB_PASSWORD value: RedHat123 - name: WORDPRESS_DB_NAME value: wordpress - name: WORDPRESS_DB_HOST value: 10.96.240.104 #修改这个IP，为serviceIP - name: WORDPRESS_DB_USER value: root
2.5 外部访问wordpress
[root@docker-server1 svcs]# vi wordpress-svc.yaml
apiVersion: v1 kind: Service metadata: name: wordpress spec: selector: app: wordpress type: NodePort #为node节点配置端口映射 ports: - port: 80 targetPort: 80 nodePort: 32080
[root@docker-server1 svcs]# kubectl apply -f wordpress-svc.yaml
[root@docker-server1 svcs]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 11h mysql-svc ClusterIP 10.96.240.104 <none> 3306/TCP 16m wordpress NodePort 10.96.72.115 <none> 80:32080/TCP 2s
[root@docker-server1 svcs]# netstat -ntlp|grep 32080
2.6 查看详细信息
[root@docker-server1 ~]# kubectl describe svc mysql-svc
Name: mysql-svc Namespace: default Labels: <none> Annotations: <none> Selector: app=mysql Type: ClusterIP IP: 10.96.240.104 Port: <unset> 3306/TCP TargetPort: 3306/TCP Endpoints: 10.244.1.22:3306 Session Affinity: None Events: <none>
[root@docker-server1 ~]# kubectl describe svc wordpress
Name: wordpress Namespace: default Labels: <none> Annotations: kubectl.kubernetes.io/last-applied-configuration: {"apiVersion":"v1","kind":"Service","metadata":{"annotations":{},"name":"wordpress","namespace":"default"},"spec":{"ports":[{"nodePort":32... Selector: app=wordpress Type: NodePort IP: 10.96.72.115 Port: <unset> 80/TCP TargetPort: 80/TCP NodePort: <unset> 32080/TCP Endpoints: 10.244.0.6:80 Session Affinity: None External Traffic Policy: Cluster Events: <none>
2.7 查看iptables
[root@docker-server1 ~]# iptables -t nat -L|grep 32080
KUBE-MARK-MASQ tcp -- anywhere anywhere /* default/wordpress: */ tcp dpt:32080 KUBE-SVC-2T26TNVTRAU2MSW5 tcp -- anywhere anywhere /* default/wordpress: */ tcp dpt:32080
[root@docker-server1 ~]# iptables -t nat -L
KUBE-MARK-MASQ tcp -- !docker-server1/16 10.96.240.104 /* default/mysql-svc: cluster IP */ tcp dpt:mysql KUBE-SVC-USVAXDL4J4VMVCQU tcp -- anywhere 10.96.240.104 /* default/mysql-svc: cluster IP */ tcp dpt:mysql KUBE-MARK-MASQ tcp -- !docker-server1/16 10.96.72.115 /* default/wordpress: cluster IP */ tcp dpt:http KUBE-SVC-2T26TNVTRAU2MSW5 tcp -- anywhere 10.96.72.115 /* default/wordpress: cluster IP */ tcp dpt:http KUBE-MARK-MASQ udp -- !docker-server1/16 10.96.0.10 /* kube-system/kube-dns:dns cluster IP */ udp dpt:domain KUBE-SVC-TCOU7JCQXEZGVUNU udp -- anywhere 10.96.0.10 /* kube-system/kube-dns:dns cluster IP */ udp dpt:domain KUBE-MARK-MASQ tcp -- !docker-server1/16 10.96.0.10 /* kube-system/kube-dns:dns-tcp cluster IP */ tcp dpt:domain KUBE-SVC-ERIFXISQEP7F7OF4 tcp -- anywhere 10.96.0.10 /* kube-system/kube-dns:dns-tcp cluster IP */ tcp dpt:domain KUBE-MARK-MASQ tcp -- !docker-server1/16 10.96.0.10 /* kube-system/kube-dns:metrics cluster IP */ tcp dpt:9153 KUBE-SVC-JD5MR3NA4I4DYORP tcp -- anywhere 10.96.0.10 /* kube-system/kube-dns:metrics cluster IP */ tcp dpt:9153 KUBE-MARK-MASQ tcp -- !docker-server1/16 10.96.93.119 /* kubernetes-dashboard/dashboard-metrics-scraper: cluster IP */ tcp dpt:irdmi KUBE-SVC-NDSMHFCKXJRPU4FV tcp -- anywhere 10.96.93.119 /* kubernetes-dashboard/dashboard-metrics-scraper: cluster IP */ tcp dpt:irdmi KUBE-MARK-MASQ tcp -- !docker-server1/16 10.96.87.98 /* kubernetes-dashboard/kubernetes-dashboard: cluster IP */ tcp dpt:https KUBE-SVC-4CRUJHTV5RT5YMFY tcp -- anywhere 10.96.87.98 /* kubernetes-dashboard/kubernetes-dashboard: cluster IP */ tcp dpt:https KUBE-MARK-MASQ tcp -- !docker-server1/16 10.96.0.1 /* default/kubernetes:https cluster IP */ tcp dpt:https
2.8 外部配置wordpress
访问：http://192.168.132.131:32080
选择简体中文
配置邮件
登录
输入用户名密码
最终界面
配置完成
博主声明：本文的内容来源主要来自誉天教育晏威老师，由本人实验完成操作验证，需要的博友请联系誉天教育（http://www.yutianedu.com/），获得官方同意或者晏老师（https://www.cnblogs.com/breezey/）本人同意即可转载，谢谢！