Shulou(Shulou.com)05/31 Report--

Today, I will talk to you about the basic concept of K8S, which may not be well understood by many people. in order to make you understand better, the editor has summarized the following contents for you. I hope you can get something according to this article.

I. background

Recently, the company is going to build a micro-service project, and the previous way of docker-compose deployment needs to be replaced with K8S, and then, , this opportunity has come to me again. Although I don't know how to deploy it, I am still very happy to be able to learn and use it at the same time.

II. Overview of K8S

Kubernetes is a lightweight and extensible open source platform for managing containerized applications and services. Automatic deployment and expansion of applications can be carried out through Kubernetes. In Kubernetes, the containers that make up the application are combined into a logical unit for easier management and discovery. Kubernetes has accumulated 15 years of experience running workloads as a Google production environment and has absorbed best ideas and practices from the community.

Third, K8S function 1. Automatic packing

Based on the resource configuration requirements of the container to the application running environment, the application container is automatically deployed.

two。 Self-healing (self-healing)

When the container fails, the container will be restarted. If there is a problem with the deployed Node node, the container will be redeployed and rescheduled. If the container fails the monitoring check, the container will be closed until the container is running normally and services will not be provided to the outside world.

3. Horizontal expansion

Scale up or tailor the application container through simple commands, user UI interfaces, or based on resource usage such as CPU

4. Service discovery

Users can realize service discovery and load balancing based on Kubernetes's own capabilities without using additional service discovery mechanism.

5. Scrolling update

According to the changes of the application, you can update the application running by the application container in an one-time or batch manner.

6. Version fallback

You can roll back the historical version of the application running by the application container according to the deployment of the application.

7. Key and configuration management

Without the need to rebuild the image, you can deploy and update keys and application configurations, similar to hot deployment.

8. Storage choreography

Automatic storage system mount and application, especially for stateful applications, data persistence is very important. Storage system can come from local directory, network storage (NFS, Gluster, Ceph, etc.), public cloud storage service.

9. Batch processing

Provide one-time tasks, scheduled tasks; scenarios that meet batch data processing and analysis

4. K8S cluster architecture components

1. Master Node

K8s cluster control node, which schedules and manages the cluster and accepts requests from users outside the cluster to go to the cluster. Master Node consists of API Server, Scheduler, ClusterState Store (ETCD database) and Controller MangerServer

API Server: unified entry to the cluster, which is delivered to etcd for storage in restful mode

Scheduler: node scheduling, select node node application deployment

Controller-manager: handles regular background tasks in the cluster, with one resource corresponding to one controller

Etcd: storage system for storing cluster-related data

2. Worker Node

Cluster work node, which runs the user's business application container; Worker Node contains kubelet, kube proxy and ContainerRuntime

Kube proxy: provide network proxy, load balancing and other operations kube let:master send to node node representative, manage native container 5, K8S core concept 1. Pod minimum deployment unit set of containers the collection and sharing network life cycle is short 2. Controller ensures the expected number of pod replicas stateless application deployment stateful application deployment ensures that all node run the same pod one-time task and timing task 3. Service

Define a set of access rules for pod

After reading the above, do you have any further understanding of the basic concept of K8S? If you want to know more knowledge or related content, please follow the industry information channel, thank you for your support.

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