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Kubernetes represents a powerful container orchestration platform designed to automate the deployment, scaling, and management of containerized applications. This article explores the fundamental architecture and essential concepts that form the backbone of Kubernetes clusters. Kubernetes Architecture Overview The Kubernetes architecture consis ...

Storage Configuration This deployment uses NFS for persistent storage. Ensure a StorageClass named nfs-storage is already configured in your cluster. Create Namespace kubectl create namespace ops Configure RBAC Permissions Define a service account, cluster role, and binding to grant Jenkins necessary permissions: # ServiceAccount apiVersion: ...

Understanding cgroups Before addressing the configuration issue, it's essential to understand what cgroups represents in the Linux kernel. cgroupfs is a virtual filesystem type developed to provide user-facing operations for control groups. It presents the cgroup hierarchy to users, communicates kernel changes requested by users, and handles al ...

Core Concepts and Terminology in Kubernetes Most concepts in Kubernetes—such as Node, Pod, Replication Controller, and Service—can be considered "resource objects." Almost all resource objects can be created, read, updated, deleted, or otherwise manipulated via the kubectl command-line tool (or API calls) provided by Kubernetes, and t ...

Overview of Kubernetes Architecture Kubernetes clsuters consist of two main types of nodes: Control Plane (Master): etcd: A distributed key-value store used for cluster state managemant. kube-apiserver: The entry point for all REST commands and cluster interactions. kube-controller-manager: Handles routine tasks such as replication and nod ...

Kubernetes controllers, schedulers, and kubelets stay in-sync by streaming resource changes from the API server. The underlying transport is nothing exotic—just plain HTTP/1.1 kept alive with Transfer-Encoding: chunked. This article strips the problem down to the wire format and shows how the chunking mechanism is used to deliver watch events. ...

Preparing Host System Configuration on All Nodes Configure System Package Repository Replace the default system repository with an Aliyun mirror for faster package downloads. mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-7.repo sed - ...

Container Security Best Practices and Essential Tools Understanding Container Security Container security encompasses the measures and strategies designed to protect containerized applications and infrastructure from potential threats and attacks. Containerization technologies like Docker and Kubernetes enable applications to run in isolated en ...

DNS Resolution PhaseWhen a client attempts to reach a domain like app.example.com, it first queries a DNS server. The resolution yields different results based on the service exposure strategy:External IP (e.g., 198.51.100.10): Returned when the application is exposed externally via a LoadBalancer or an Ingress resource.Cluster-internal IP (e.g ...

Environment Overview Hostname OS Version IP Address Components Hardware Role master01 CentOS 7.6.1810 172.27.34.3 Docker 18.09.9, Flannel v0.11.0, Keepalived v1.3.5 4C4G control plane master02 CentOS 7.6.1810 172.27.34.4 Docker 18.09.9, Flannel v0.11.0, Keepalived v1.3.5 4C4G control plane master03 CentOS 7.6.1810 172.27.34.5 Docker ...