Kubernetes创建资源的方式 命令创建 17版本可以使用命令直接创建，如：
1 kubectl run httpd-app --image=httpd --replicas=2
会提示：
18版本之后可以先创建后伸缩
1 2 kubectl create deployment --image=nginx:1.7.9 nginx-deployment kubectl scale deployment nginx-deployment --replicas=2
yaml/yml文件创建 1 kubectl apply -f xxx.yml
使用Deployment运行应用 k8s作为容器编排引擎，最重要也是最基本的功能当然是运行容器话应用。
创建pod 1 2 3 4 kubectl create deployment --image=nginx:1.7.9 nginx-deployment deployment.apps/nginx-deployment created kubectl scale deployment nginx-deployment --replicas=2 deployment.apps/nginx-deployment scaled
查看部署结果 1 2 3 4 5 6 7 8 9 # 查看 Deployment kubectl get deployment NAME READY UP-TO-DATE AVAILABLE AGE nginx-deployment 2/2 2 2 109s # 查看 Pod kubectl get pod -o wide NAME READY STATUS RESTARTS AGE IP NODE nginx-deployment-6dd8bc586b-h4262 1/1 Running 0 42m 10.244.1.5 node3 nginx-deployment-6dd8bc586b-wl4bq 1/1 Running 0 42m 10.244.2.3 node2
可以看到一个名为nginx-deployment的Deployment和两个名为nginx-deployment-xxxxxxx的副本Pod
分析创建Deployment过程中，k8s是怎么运行的 查看Deployment的详细信息 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 [root@node1 ~]# kubectl describe deployments.apps nginx-deployment Name: nginx-deployment # Deployment名字 Namespace: default # 所在命名空间 CreationTimestamp: Thu, 07 May 2020 19:06:18 +0800 # 创建时间 Labels: app=nginx Annotations: deployment.kubernetes.io/revision: 1 Selector: app=nginx Replicas: 2 desired | 2 updated | 2 total | 2 available | 0 unavailable # 目标的期望状态，期望2，更新2，总共2，在使用2，坏掉的0 StrategyType: RollingUpdate MinReadySeconds: 0 RollingUpdateStrategy: 25% max unavailable, 25% max surge Pod Template: # Pod运行状态 Labels: app=nginx Containers: # 容器 nginx: Image: nginx:1.7.9 # 容器使用镜像 Port: <none> # 容器端口 Host Port: <none> # 容器端口在主机上的映射端口 Environment: <none> # 设置过的变量值 Mounts: <none> # 挂载 Volumes: <none> # 映射卷 Conditions: Type Status Reason ---- ------ ------ Available True MinimumReplicasAvailable Progressing True NewReplicaSetAvailable OldReplicaSets: <none> NewReplicaSet: nginx-deployment-6dd8bc586b (2/2 replicas created) Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal ScalingReplicaSet 14m deployment-controller Scaled up replica set nginx-deployment-6dd8bc586b to 1 Normal ScalingReplicaSet 14m deployment-controller Scaled up replica set nginx-deployment-6dd8bc586b to 2
查看ReplicaSet的详细信息 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 [root@node1 ~]# kubectl describe replicaset Name: nginx-deployment-6dd8bc586b Namespace: default Selector: app=nginx,pod-template-hash=6dd8bc586b Labels: app=nginx pod-template-hash=6dd8bc586b Annotations: deployment.kubernetes.io/desired-replicas: 2 deployment.kubernetes.io/max-replicas: 3 deployment.kubernetes.io/revision: 1 Controlled By: Deployment/nginx-deployment # 记录了ReplicaSet是由Deployment(nginx-deployment)创建的 Replicas: 2 current / 2 desired Pods Status: 2 Running / 0 Waiting / 0 Succeeded / 0 Failed Pod Template: Labels: app=nginx pod-template-hash=6dd8bc586b Containers: nginx: Image: nginx:1.7.9 Port: <none> Host Port: <none> Environment: <none> Mounts: <none> Volumes: <none> Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal SuccessfulCreate 16m replicaset-controller Created pod: nginx-deployment-6dd8bc586b-h4262 Normal SuccessfulCreate 15m replicaset-controller Created pod: nginx-deployment-6dd8bc586b-wl4bq
查看Pod的详细信息 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 [root@node1 ~]# kubectl describe pod nginx-deployment-6dd8bc586b-wl4bq Name: nginx-deployment-6dd8bc586b-wl4bq Namespace: default Priority: 0 Node: node2/192.168.1.12 Start Time: Thu, 07 May 2020 19:06:18 +0800 Labels: app=nginx pod-template-hash=6dd8bc586b Annotations: <none> Status: Running IP: 10.244.2.3 IPs: IP: 10.244.2.3 Controlled By: ReplicaSet/nginx-deployment-6dd8bc586b # 该Pod由ReplicaSet创建 Containers: nginx: Container ID: docker://fcfa9364fd4f67dfd722fc25dbe734909025fff8a1f1502476503489a109dbfd Image: nginx:1.7.9 Image ID: docker-pullable://nginx@sha256:e3456c851a152494c3e4ff5fcc26f240206abac0c9d794affb40e0714846c451 Port: <none> Host Port: <none> State: Running Started: Thu, 07 May 2020 19:06:55 +0800 Ready: True Restart Count: 0 Environment: <none> Mounts: /var/run/secrets/kubernetes.io/serviceaccount from default-token-cdzqz (ro) Conditions: Type Status Initialized True Ready True ContainersReady True PodScheduled True Volumes: default-token-cdzqz: Type: Secret (a volume populated by a Secret) SecretName: default-token-cdzqz Optional: false QoS Class: BestEffort Node-Selectors: <none> Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s node.kubernetes.io/unreachable:NoExecute for 300s Events: Type Reason Age From Message ---- ------ ---- ---- ------- Normal Scheduled 17m default-scheduler Successfully assigned default/nginx-deployment-788b8d7b98-6cpwt to node2 Normal Pulled 17m kubelet, node2 Container image "nginx:1.7.9" already present on machine Normal Created 17m kubelet, node2 Created container nginx Normal Started 17m kubelet, node2 Started container nginx
Pod创建过程： 1.用户通过kubectl创建Deployment
最终容器名字的组成：k8s_标签名_Deployment名-ReplicaSet名-Pod名_所在命名空间名_容器id
