部署之前先来回顾一下K8s中的核心概念:
◎Replication Controller ，RC
◎Replica Set ，RS
◎Deployment
◎Service
1.创建第一个k8s应用
1.创建一个测试用的deployment
[root@linux-node1 ~]# kubectl run net-test --image=alpine --replicas=2 sleep 360000 deployment.apps "net-test" created
2.查看获取IP情况
[root@linux-node1 ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE net-test-5767cb94df-dk28b 1/1 Running 0 2m 10.2.91.2 192.168.56.12 net-test-5767cb94df-fh4vr 1/1 Running 0 2m 10.2.38.2 192.168.56.13
3.测试联通性
[root@linux-node1 ~]# ping -c 2 10.2.38.2 PING 10.2.38.2 (10.2.38.2) 56(84) bytes of data. 64 bytes from 10.2.38.2: icmp_seq=1 ttl=63 time=0.291 ms 64 bytes from 10.2.38.2: icmp_seq=2 ttl=63 time=1.31 ms
2.创建nginx deployment
1.创建一个nginx的deployment
[root@linux-node1 ~]# cat nginx-deployment.yaml apiVersion: apps/v1 kind: Deployment metadata: name: nginx-deployment labels: app: nginx spec: replicas: 3 selector: matchLabels: app: nginx template: metadata: labels: app: nginx spec: containers: - name: nginx image: nginx:1.13.12 ports: - containerPort: 80 [root@linux-node1 ~]# kubectl create -f nginx-deployment.yaml deployment.apps "nginx-deployment" created
2.查看deployment及详细信息
[root@linux-node1 ~]# kubectl get deployment NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE net-test 2 2 2 2 7m nginx-deployment 3 3 3 0 1m [root@linux-node1 ~]# kubectl describe deployment nginx-deployment Name: nginx-deployment Namespace: default CreationTimestamp: Sun, 23 Sep 2018 22:24:39 +0800 Labels: app=nginx Annotations: deployment.kubernetes.io/revision=1 Selector: app=nginx Replicas: 3 desired | 3 updated | 3 total
3.查看pod信息
[root@linux-node1 ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE net-test-5767cb94df-dk28b 1/1 Running 0 12m 10.2.91.2 192.168.56.12 net-test-5767cb94df-fh4vr 1/1 Running 0 12m 10.2.38.2 192.168.56.13 nginx-deployment-6c45fc49cb-42sgq 1/1 Running 0 6m 10.2.91.3 192.168.56.12 nginx-deployment-6c45fc49cb-f9sj5 1/1 Running 0 6m 10.2.38.3 192.168.56.13 nginx-deployment-6c45fc49cb-tmgld 1/1 Running 0 6m 10.2.38.4 192.168.56.13
4.访问nginx
[root@linux-node1 ~]# curl --head http://10.2.91.3 HTTP/1.1 200 OK Server: nginx/1.13.12 Date: Sun, 23 Sep 2018 14:35:05 GMT Content-Type: text/html Content-Length: 612 Last-Modified: Mon, 09 Apr 2018 16:01:09 GMT Connection: keep-alive ETag: "5acb8e45-264" Accept-Ranges: bytes
5.更新deployment,常用于升降级
[root@linux-node1 ~]# kubectl set image deployment/nginx-deployment nginx=nginx:1.12.2 --record deployment.apps "nginx-deployment" image updated [root@linux-node1 ~]# kubectl get deployment -o wide NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE CONTAINERS IMAGES SELECTOR net-test 2 2 2 2 20m net-test alpine run=net-test nginx-deployment 3 4 1 3 14m nginx nginx:1.12.2 app=nginx #查看版本是否降级 [root@linux-node1 ~]# curl --head http://10.2.91.4 HTTP/1.1 200 OK Server: nginx/1.12.2 Date: Sun, 23 Sep 2018 14:41:21 GMT Content-Type: text/html Content-Length: 612 Last-Modified: Tue, 11 Jul 2017 13:29:18 GMT Connection: keep-alive ETag: "5964d2ae-264" Accept-Ranges: bytes #查看回滚记录 [root@linux-node1 ~]# kubectl rollout history deployment/nginx-deployment deployments "nginx-deployment" REVISION CHANGE-CAUSE 1 <none> 2 kubectl set image deployment/nginx-deployment nginx=nginx:1.12.2 --record=true
6.快速回滚到上一版本
#查看具体某一个版本的历史 [root@linux-node1 ~]# kubectl rollout history deployment/nginx-deployment --revision=1 deployments "nginx-deployment" with revision #1 Pod Template: Labels: app=nginx pod-template-hash=2701970576 Containers: nginx: Image: nginx:1.13.12 Port: 80/TCP Host Port: 0/TCP Environment: <none> Mounts: <none> Volumes: <none> #快速回滚到上一个版本 [root@linux-node1 ~]# kubectl rollout undo deployment/nginx-deployment deployment.apps "nginx-deployment" [root@linux-node1 ~]# curl --head http://10.2.38.7 HTTP/1.1 200 OK Server: nginx/1.13.12 Date: Sun, 23 Sep 2018 14:49:24 GMT Content-Type: text/html Content-Length: 612 Last-Modified: Mon, 09 Apr 2018 16:01:09 GMT Connection: keep-alive ETag: "5acb8e45-264" Accept-Ranges: bytes
Pod的IP每次都会变化，因此我们需要创建一个service,通过VIP来访问。
3.创建nginx service
1.创建一个nginx的service
[root@linux-node1 ~]# cat nginx-service.yaml kind: Service apiVersion: v1 metadata: name: nginx-service spec: selector: app: nginx ports: - protocol: TCP port: 80 targetPort: 80 [root@linux-node1 ~]# kubectl create -f nginx-service.yaml service "nginx-service" created
2.访问service
[root@linux-node1 ~]# kubectl get service -o wide NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE SELECTOR kubernetes ClusterIP 10.1.0.1 <none> 443/TCP 9h <none> nginx-service ClusterIP 10.1.179.125 <none> 80/TCP 2m app=nginx #在node2上访问VIP没有问题 [root@linux-node2 ~]# curl --head http://10.1.179.125 HTTP/1.1 200 OK Server: nginx/1.13.12 Date: Sun, 23 Sep 2018 14:57:21 GMT Content-Type: text/html Content-Length: 612 Last-Modified: Mon, 09 Apr 2018 16:01:09 GMT Connection: keep-alive ETag: "5acb8e45-264" Accept-Ranges: bytes #通过ipvs转发实现负载均衡 [root@linux-node2 ~]# ipvsadm -Ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 10.1.0.1:443 rr persistent 10800 -> 192.168.56.11:6443 Masq 1 0 0 TCP 10.1.179.125:80 rr -> 10.2.38.6:80 Masq 1 0 0 -> 10.2.38.7:80 Masq 1 0 0 -> 10.2.91.6:80 Masq 1 0 1
3.快速扩容
[root@linux-node1 ~]# kubectl scale deployment nginx-deployment --replicas 5 deployment.extensions "nginx-deployment" scaled [root@linux-node1 ~]# kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE net-test-5767cb94df-dk28b 1/1 Running 0 42m 10.2.91.2 192.168.56.12 net-test-5767cb94df-fh4vr 1/1 Running 0 42m 10.2.38.2 192.168.56.13 nginx-deployment-6c45fc49cb-42mqn 1/1 Running 0 14s 10.2.38.8 192.168.56.13 nginx-deployment-6c45fc49cb-bsr2k 1/1 Running 0 13m 10.2.38.7 192.168.56.13 nginx-deployment-6c45fc49cb-qv9rd 1/1 Running 0 13m 10.2.91.6 192.168.56.12 nginx-deployment-6c45fc49cb-rqn6x 1/1 Running 0 13m 10.2.38.6 192.168.56.13 nginx-deployment-6c45fc49cb-sq4cw 1/1 Running 0 14s 10.2.91.7 192.168.56.12 [root@linux-node2 ~]# ipvsadm -Ln IP Virtual Server version 1.2.1 (size=4096) Prot LocalAddress:Port Scheduler Flags -> RemoteAddress:Port Forward Weight ActiveConn InActConn TCP 10.1.0.1:443 rr persistent 10800 -> 192.168.56.11:6443 Masq 1 0 0 TCP 10.1.179.125:80 rr -> 10.2.38.6:80 Masq 1 0 0 -> 10.2.38.7:80 Masq 1 0 0 -> 10.2.38.8:80 Masq 1 0 0 -> 10.2.91.6:80 Masq 1 0 0 -> 10.2.91.7:80 Masq 1 0 0
