In this scenario, you'll learn how to use Kubectl to create and launch Deployments, Replication Controllers and expose them via Services without writing yaml definitions. This allows you to quickly launch containers onto the cluster.

Step 1 - Launch Cluster

To start we need to launch a Kubernetes cluster.

Execute the command below to start the cluster components and download the Kubectl CLI.

minikube start

Wait for the Node to become Ready by checking

kubectl get nodes

Step 2 - Kubectl Run

The run command creates a deployment based on the parameters specified, such as the image or replicas. This deployment is issued to the Kubernetes master which launches the Pods and containers required. Kubectl run_ is similar to docker run but at a cluster level.

The format of the command is kubectl run <name of deployment> <properties>

The following command will launch a deployment called http which will start a container based on the Docker Image katacoda/docker-http-server:latest.

kubectl run http --image=katacoda/docker-http-server:latest --replicas=

You can then use kubectl to view the status of the deployments

kubectl get deployments

To find out what Kubernetes created you can describe the deployment process.

kubectl describe deployment http

The description includes how many replicas are available, labels specified and the events associated with the deployment. These events will highlight any problems and errors that might have occurred.

In the next step we'll expose the running service.

Step 3 - Kubectl Expose

With the deployment created, we can use kubectl to create a service which exposes the Pods on a particular port.

Expose the newly deployed http deployment via kubectl expose. The command allows you to define the different parameters of the service and how to expose the deployment.

Use the following command to expose the container port 80 on the host 8000binding to the external-ip of the host.

kubectl expose deployment http --external-ip="172.17.0.30" --port= --target-port=

You will then be able to ping the host and see the result from the HTTP service.

curl http://172.17.0.30:8000

Step 4 - Kubectl Run and Expose

With kubectl run it's possible to create the deployment and expose it as a single command.

Use the command command to create a second http service exposed on port 8001.

kubectl run httpexposed --image=katacoda/docker-http-server:latest --replicas= --port= --hostport=

You should be able to access it using

curl http://172.17.0.30:8001

Under the covers, this exposes the Pod via Docker Port Mapping. As a result, you will not see the service listed using

kubectl get svc

To find the details you can use docker ps | grep httpexposed

Pause Containers

Running the above command you'll notice the ports are exposed on the Pod, not the http container itself. The Pause container is responsible for defining the network for the Pod. Other containers in the pod share the same network namespace. This improves network performance and allow multiple containers to communicate over the same network interface..

Step 5 - Scale Containers

With our deployment running we can now use kubectl to scale the number of replicas.

Scaling the deployment will request Kubernetes to launch additional Pods. These Pods will then automatically be load balanced using the exposed Service.

The command kubectl scale allows us to adjust the number of Pods running for a particular deployment or replication controller.

kubectl scale --replicas= deployment http

Listing all the pods, you should see three running for the http deployment

kubectl get pods

Once each Pod starts it will be added to the load balancer service. By describing the service you can view the endpoint and the associated Pods which are included.

kubectl describe svc http

Making requests to the service will request in different nodes processing the request.

curl http://172.17.0.30:8000

Kubernetes - Start containers using Kubectl的更多相关文章

  1. 高可用Kubernetes集群-4. kubectl客户端工具

    六.部署kubectl客户端工具 1. 下载 [root@kubenode1 ~]# cd /usr/local/src/ [root@kubenode1 src]# wget https://sto ...

  2. Kubernetes - Deploy Containers Using YAML

    In this scenario, you'll learn how to use Kubectl to create and launch Deployments, Replication Cont ...

  3. kubernetes 实践二:kubectl命令使用

    这里记录kubernetes学习和使用过程中的内容. CentOS7 k8s-1.13 flanneld-0.10 docker-18.06 etcd-3.3 kubectl用法概述 kubectl是 ...

  4. K8S从入门到放弃系列-(4)kubernetes集群之kubectl命令行工具部署

    摘要:随着版本的不断迭代,k8s为了集群安全,集群中趋向采用TLS+RBAC的安全配置方式,所以我们在部署过程中,所有组件都需要证书,并启用RBAC认证. 我们这里采用二进制安装,下载解压后,把对应组 ...

  5. 九、kubernetes命令行工具kubectl

    为了方便在命令行下对集群.节点.pod进行管理,kubernetes官方提供了一个管理命令:kubectl kubectl作为客户端CLI工具,可以让用户通过命令行对Kubernetes集群进行操作. ...

  6. [Kubernetes]安装和配置kubectl

    安装kubectl 安装kubectl比较简单,几条命令即可(#后面为注释内容): #下载最新版本: curl -LO https://storage.googleapis.com/kubernete ...

  7. kubernetes 实战6_命令_Share Process Namespace between Containers in a Pod&Translate a Docker Compose File to Kubernetes Resources

    Share Process Namespace between Containers in a Pod how to configure process namespace sharing for a ...

  8. kubernetes 实战4_命令_Configure Pods and Containers

    Configure Service Accounts for Pods A service account provides an identity for processes that run in ...

  9. Kubernetes源码之旅:从kubectl到API Server

    概述: Kubernetes项目目前依然延续着之前爆炸式的扩张.急需能够理解Kubernetes原理并且贡献代码的软件开发者.学习Kubernetes源码并不容易.Kubernetes是使用相对年轻的 ...

随机推荐

  1. Python3 Tkinter-Grid

    1.创建 from tkinter import * root=Tk() lb1=Label(root,text='Hello') lb2=Label(root,text='Grid') lb1.gr ...

  2. 5.hadoop常用命令

    1. 单独启动和关闭hadoop服务 启动名称节点 #hadoop-daemon.sh start namenode 启动数据节点 #hadoop-daemons.sh start datanode ...

  3. SGU 520 Fire in the Country(博弈+搜索)

    Description This summer's heat wave and drought unleashed devastating wildfires all across the Earth ...

  4. Centos7 下nginx nginx-1.13.4 安装

    环境:CentOS Linux release 7.3.1611 (Core)  Linux localhost.localdomain 3.10.0-514.26.2.el7.x86_64 #1 S ...

  5. 第一章 Windows编程基础(1~4课)

    第一课:从main到WinMain 第二课:窗口和消息 第三课:MFC编程 第四课:MFC应用程序框架 概括: Win32的两种编程框架:SDK方式.MFC方式 1. SDK方式:使用WinMain入 ...

  6. Thunder团队第三周 - Scrum会议7

    Scrum会议7 小组名称:Thunder 项目名称:i阅app Scrum Master:胡佑蓉 工作照片: 邹双黛在照相,所以图片中没有该同学. 参会成员: 王航:http://www.cnblo ...

  7. java面试95题

    1.面向对象的特征有哪些方面? 答:面向对象的特征主要有以下几个方面: - 抽象:抽象是将一类对象的共同特征总结出来构造类的过程,包括数据抽象和行为抽象两方面.抽象只关注对象有哪些属性和行为,并不关注 ...

  8. ZOJ 2072 K-Recursive Survival

    https://vjudge.net/contest/67836#problem/K n people numbered 1 to n around a circle, we eliminate ev ...

  9. Code Quality

    Code Quality https://www.sonarqube.org/ java https://www.sonarsource.com/products/codeanalyzers/sona ...

  10. query 获取本身的HTML

    <div class="test"><p>hello,你好!</p></div> <script> $(".t ...