[root@k8s-master1 service_pod]# kubectl get pod
NAME? ? ? ? ? ? ? ? ? ?? READY? ?? STATUS? ? RESTARTS?? AGE
mysql-5bbbf49b4f-p7zkz?? 1/1? ? ?? Running?? 0? ? ? ? ? 2m
mysql-5bbbf49b4f-vhj44?? 1/1? ? ?? Running?? 1? ? ? ? ? 2m
mysql-5bbbf49b4f-xzpwn?? 1/1? ? ?? Running?? 1? ? ? ? ? 2m
[root@k8s-master1 service_pod]#
 

想擴大到5個pod
官方參考命令格式，見下：

Examples:
? # Scale a replicaset named ‘foo‘ to 3.
? kubectl scale --replicas=3 rs/foo

? # Scale a resource identified by type and name specified in "foo.yaml" to 3.
? kubectl scale --replicas=3 -f foo.yaml

? # If the deployment named mysql‘s current size is 2, scale mysql to 3.
? kubectl scale --current-replicas=2 --replicas=3 deployment/mysql

? # Scale multiple replication controllers.
? kubectl scale --replicas=5 rc/foo rc/bar rc/baz

? # Scale statefulset named ‘web‘ to 3.
? kubectl scale --replicas=3 statefulset/web
 

2.
減少pod
測試下參考命令

[root@k8s-master1 service_pod]# kubectl get deployment
NAME? ? ? DESIRED?? CURRENT?? UP-TO-DATE?? AVAILABLE?? AGE
mysql? ?? 3? ? ? ?? 3? ? ? ?? 3? ? ? ? ? ? 3? ? ? ? ?? 9m

[root@k8s-master1 service_pod]# kubectl scale --current-replicas=3 --replicas=1 deployment/mysql
deployment.extensions "mysql" scaled

[root@k8s-master1 service_pod]# kubectl get deployment
NAME? ? ? DESIRED?? CURRENT?? UP-TO-DATE?? AVAILABLE?? AGE
mysql? ?? 1? ? ? ?? 1? ? ? ?? 1? ? ? ? ? ? 1? ? ? ? ?? 10m
 

3.
增加pod
測試下命令

[root@k8s-master1 service_pod]# kubectl get deployment
NAME? ? ? DESIRED?? CURRENT?? UP-TO-DATE?? AVAILABLE?? AGE
mysql? ?? 1? ? ? ?? 1? ? ? ?? 1? ? ? ? ? ? 1? ? ? ? ?? 13m

[root@k8s-master1 service_pod]# kubectl scale --current-replicas=1 --replicas=3 deployment/mysql
deployment.extensions "mysql" scaled

[root@k8s-master1 service_pod]# kubectl get pod
NAME? ? ? ? ? ? ? ? ? ?? READY? ?? STATUS? ? RESTARTS?? AGE
mysql-5bbbf49b4f-96v7g?? 1/1? ? ?? Running?? 0? ? ? ? ? 5s
mysql-5bbbf49b4f-f6rlg?? 1/1? ? ?? Running?? 0? ? ? ? ? 5s
mysql-5bbbf49b4f-p7zkz?? 1/1? ? ?? Running?? 0? ? ? ? ? 13m
[root@k8s-master1 service_pod]#

k8s日常使用命令scale彈性伸縮pod