【K8S运维知识汇总】第3天1：kubectl详解——陈述式资源管理方法(deployment资源、service资源)

查看名称空间：

[root@hdss7-21 ~]# kubectl get namespace　# 等同于kubectl get nsNAME STATUS AGEdefault Active 3d22hkube-node-lease Active 3d22hkube-public Active 3d22hkube-system Active 3d22h

查看defalut名称空间下的所有资源：

[root@hdss7-21 ~]# kubectl get all -n default # 等同于kubectl get allNAME READY STATUS RESTARTS AGEpod/nginx-ds-pqszs 1/1 Running 0 2d12hpod/nginx-ds-vnlx9 1/1 Running 0 2d12hNAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGEservice/kubernetes ClusterIP 192.168.0.1 443/TCP 3d23hNAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGEdaemonset.apps/nginx-ds 0 0 0 0 0

创建名称空间：

[root@hdss7-21 ~]# kubectl create namespace appnamespace/app created[root@hdss7-21 ~]# kubectl get nsNAME STATUS AGEapp Active 45sdefault Active 3d23hkube-node-lease Active 3d23hkube-public Active 3d23hkube-system Active 3d23h

删除名称空间：

[root@hdss7-21 ~]# kubectl delete namespace appnamespace "app" deleted[root@hdss7-21 ~]# kubectl get nsNAME STATUS AGEdefault Active 3d23hkube-node-lease Active 3d23hkube-public Active 3d23hkube-system Active 3d23h

创建deployment资源：

# 在名称为kube-public的名称空间创建名称为nginx-db资源进行pod控制[root@hdss7-21 ~]# kubectl create deployment nginx-dp --image=harbor.od.com/public/nginx:v1.7.9 -n kube-publicdeployment.apps/nginx-db created[root@hdss7-21 ~]# kubectl get deploy -n kube-publicNAME READY UP-TO-DATE AVAILABLE AGEnginx-db 0/1 1 0 2m28s[root@hdss7-21 ~]# kubectl get pods -n kube-publicNAME READY STATUS RESTARTS AGEnginx-db-7b4dd9978d-8wzdl 0/1 Pending 0

查看 kube-public名称空间下的Pod

[root@hdss7-21 ~]# kubectl get pods -n kube-public -o wideNAME READY STATUS RESTARTS AGE IP NODE NOMINATED NODE READINESS GATESnginx-db-7b4dd9978d-8wzdl 0/1 Pending 0 8m15s # 根据pod名称可以获得对应的容器，一般包含2个容器，分别是基础容器和业务容器

查看详细信息：

[root@hdss7-21 ~]# kubectl describe deployment nginx-db -n kube-publicName: nginx-dbNamespace: kube-publicCreationTimestamp: Wed, 01 Jul 2020 10:58:43 +0800Labels: app=nginx-dbAnnotations: deployment.kubernetes.io/revision: 1Selector: app=nginx-dbReplicas: 1 desired | 1 updated | 1 total | 0 available | 1 unavailableStrategyType: RollingUpdate # 发布策略：滚动升级MinReadySeconds: 0RollingUpdateStrategy: 25% max unavailable, 25% max surgePod Template: Labels: app=nginx-db Containers: nginx: Image: harbor.od.com/public/nginx:v1.7.9 Port: Host Port: Environment: Mounts: Volumes: Conditions: Type Status Reason ---- ------ ------ Available False MinimumReplicasUnavailable Progressing False ProgressDeadlineExceededOldReplicaSets: NewReplicaSet: nginx-db-7b4dd9978d (1/1 replicas created)Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal ScalingReplicaSet 17m deployment-controller Scaled up replica set nginx-db-7b4dd9978d to 1# kubectl发出的指令先找apiserver通信确认，apiserver再找scheduler确认,scheduler在最合适的节点通过kubelet来启动容器

进入pod资源

[root@hdss7-21 ~]# kubectl get pods -n kube-publicNAME READY STATUS RESTARTS AGEpod/nginx-dp-5dfc689474-fc6z9 1/1 Running 0 4s# kubectl exec可以跨主机进入不同的pod[root@hdss7-21 ~]# kubectl exec -it nginx-dp-5dfc689474-fc6z9 /bin/bash root@nginx-ds-pqszs:/# ip addr1: lo: mtu 65536 qdisc noqueue state UNKNOWN qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever8: eth0@if9: mtu 1500 qdisc noqueue state UP link/ether 02:42:ac:07:15:02 brd ff:ff:ff:ff:ff:ff inet 172.7.21.3/24 brd 172.7.21.255 scope global

删除pod资源：删除后，pod控制器会立即重启一个新的pod资源，是重启Pod的重要方法

[root@hdss7-21 ~]# kubectl delete pod nginx-db-7b4dd9978d-8wzdl -n kube-public pod "nginx-db-7b4dd9978d-8wzdl" deleted# 强制删除[root@hdss7-21 ~]# kubectl delete pod nginx-db-7b4dd9978d-8wzdl -n kube-public --force --grace-period=0

删除deployment资源

[root@hdss7-21 ~]# kubectl delete deployment nginx-db -n kube-publicdeployment.extensions "nginx-db" deleted[root@hdss7-21 ~]# kubectl get deployment -n kube-publicNo resources found.[root@hdss7-21 ~]# kubectl get pods -n kube-publicNo resources found.[root@hdss7-21 ~]#

创建service资源

# 暴露80端口[root@hdss7-21 ~]# kubectl expose deployment nginx-dp --port=80 -n kube-publicservice/nginx-dp exposed[root@hdss7-21 ~]# kubectl get all -n kube-publicNAME READY STATUS RESTARTS AGEpod/nginx-dp-5dfc689474-4dfsq 1/1 Running 0 44m NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGEservice/nginx-dp ClusterIP 192.168.103.156 80/TCP 29mNAME READY UP-TO-DATE AVAILABLE AGEdeployment.apps/nginx-dp 2/2 2 2 44mNAME DESIRED CURRENT READY AGEreplicaset.apps/nginx-dp-5dfc689474 2 2 2

查看端口是否可访问

# 当无法curl时，检查宿主机的内核中是否开启了ipv4转发功能[root@hdss7-21 ~]# cat /proc/sys/net/ipv4/ip_forward0[root@hdss7-21 ~]# echo "1" >!$echo "1" >/proc/sys/net/ipv4/ip_forward[root@hdss7-21 ~]# cat /proc/sys/net/ipv4/ip_forward1[root@hdss7-21 ~]# curl 192.168.103.156

Welcome to nginx!

If you see this page, the nginx web server is successfully installed andworking. Further configuration is required.

For online documentation and support please refer to