Kubernetes

Requirements 🔥 We need to further study and advance in kubernetes, reading source code is a necessary path. 👀 More importantly, it’s the collection of kubernetes resources. ⚠️ All resources use external links, book resources may not have links, others are personal experiences and summaries. Please contact for removal if there’s copyright infringement. 🚧 ⚠️ **Note: This article will be permanently stored in notion and will be continuously updated, providing a write channel. If you have better resources, welcome to add them on notion ~** CloudNative Learning Path ...

Today we will take a look at the theory and practice of kubernetes and gitops Command introduction First, let’s take a look at the subnaming supported by kubectl for our convenience: kubectl apply - applies the definition of one or more resources. Typically used to deploy applications or update resources. kubectl get - displays information about one or more resources. This is a common command to view the status of resources in a Kubernetes cluster. kubectl describe - Displays details of one or more resources, such as events, status, and configuration. kubectl delete - Delete resources in the Kubernetes cluster. kubectl exec - Execute commands in containers in the cluster. kubectl logs - Print container logs. kubectl create - Create one or more resources from a file or standard input. kubectl edit - Edit resources in the cluster. This will open an editor to modify the resource’s configuration. kubectl port-forward - Forward local ports to Pods in the cluster. kubectl run - Run a specified image in the cluster. kubectl scale - Adjust the number of replicas of resources (such as Deployment, ReplicaSet). kubectl rollout - Manage the deployment of resources, such as viewing status, pausing, resuming or rolling back updates. **In addition to the above commands, kubectl in Kubernetes also supports annotations: ** ...

Introduction About Kustomize GitHub Repository Get Started Kustomize is an open-source configuration management tool designed specifically for Kubernetes. It helps users customize Kubernetes objects and manage them declaratively without modifying the original YAML files . This means you can retain the basic settings for applications and components while overriding default settings with declarative YAML documents called “patches” without altering the original files. Kustomize provides a declarative approach that aligns with Kubernetes philosophy and allows customization of Kubernetes configurations in a reusable, fast, debuggable, and scalable manner. ...

Container Runtime Container Runtime runs on every node in a Kubernetes (k8s) cluster and is responsible for the entire container lifecycle. Docker is currently the most widely used. With the development of container cloud, more and more container runtimes have emerged. To solve the integration problems between these container runtimes and Kubernetes, the community introduced CRI (Container Runtime Interface) in Kubernetes version 1.5 to support more container runtimes. ...

Kubelet Component Analysis Understanding kubelet The Kubelet component runs on Node nodes, maintaining running Pods and providing Kubernetes runtime environment, mainly accomplishing the following missions: Monitor Pods assigned to this Node Mount volumes required by Pods Download Pod secrets Run containers in Pods through docker/rkt Periodically execute liveness probes defined for containers in Pods Report Pod status to other system components Report Node status The core process of kubelet managing Pods mainly includes three steps. First, kubelet obtains Pod manifests through files, HTTP endpoints, API Server, and HTTP server. Second, node management mainly involves node self-registration and node status updates. Kubelet registers node information through API Server at startup and periodically sends node information to API Server, which writes the information to etcd after receiving it. Finally, Pod startup process mainly includes steps like image pulling, container startup, probe monitoring, and status reporting. ...

Scheduler kube-scheduler is responsible for scheduling and assigning Pods to nodes within the cluster. It listens to kube-apiserver, queries for Pods that haven’t been assigned to Nodes, and then assigns nodes to these Pods based on scheduling policies (updating the Pod’s NodeName field). The scheduler needs to fully consider many factors: Fair scheduling; Efficient resource utilization; QoS; affinity and anti-affinity; data locality; inter-workload interference; deadlines. kube-scheduler scheduling is divided into two phases, predicate and priority: ...

Deep understanding of Kube-APIServer kube-apiserver is one of the most important core components of Kubernetes and mainly provides the following functions Provides REST API interface for cluster management, including authentication and authorization, data verification, cluster status changes, etc. Provides a hub for data interaction and communication between other modules (other modules query or modify data through API Server, only API Server directly operates etcd) apiserver main functions: Authentication: Use the cluster to determine identity. Authentication: Use operation CRUD, permissions are required. Access: For Kubernetes, some additional actions are required. For example, if the written value is not standardized, it needs to be modified, and verification is required after modification. Finally, it is necessary to limit the current flow to prevent maliciousness or loopholes from causing congestion. Mutating Validating +Admission Current Limit Implementation of APIServer object Access control API Server is the intermediate hub for all component interactions. ...

Before starting ETCD is the hardest of all components in Kubernetes because ETCD is stateful, not stateless. When I was doing k3s runtime design before, I learned some concepts about ETCD and Raft algorithms. As a prelude to knowledge, please go to [ETCD](https://docker.nsddd.top/Cloud-Native-k8s/24 .html) and Raft algorithm for prelude learning. **This article will explain ETCD and Raft in depth and throughout. And analyze ETCD in depth from the perspective of Kubernetes. ** ...

Conference and Reference Links Conference reference documents: https://nsddd.notion.site/2899028707604b8090b36677c031cdf8?pvs=4 Video playback: Bilibili: https://www.bilibili.com/video/BV1s8411q7Um/?spm_id_from=333.999.0.0 Comment: I think that middleware can be replaced with https://kubeblocks.io which can help you manage multiple database middlewares. im reads the configuration information, and reads the config/ directory. The config.yaml hard-coded in the code can be automatically divided into rpc for different services, and then unified directories. By default, the directory is read from the binary running path. two floors openim version: https://github.com/openimsdk/open-im-server/blob/main/docs/conversions/version.md Storage can consider using: https://github.com/openebs/openebs https://github.com/rook/rook Core target: ...

✨ Anyone who is familiar with me knows that I am an out-and-out open source enthusiast. After I came into contact with GitHub in my freshman year, I gradually became addicted to the open source world~ Today’s article is very special, I can refer to it and summarize it. The open source stage, as well as the steps and experience of learning open source projects. In the future, I will also grow according to my own plan. Like Learn the growth trajectory of Kubernetes , this article will be [updated long-term, and you can also contribute](https://www.notion . so/f8854a0f60d346d98b9eb2ccb6eaef8f) ~ ...