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--- k8s:core:introduction [2026/05/31 02:29] – created phong2018
+++ k8s:core:introduction [2026/06/12 23:22] (current) – [Kubernetes Concepts] phong2018
@@ Line 1: / Line 1: @@
 ====== What is Kubernetes ======
-Kubernetes (K8s) is an open-source system for automating deployment, scaling, and management of containerized applications.
+Kubernetes is a system that **runs and manages containerized applications automatically**.
-In simple terms:
+Instead of manually running containers, Kubernetes:
-  * You run applications in containers (like Docker)
+  * Starts them
-  * Kubernetes manages where and how those containers run
+  * Stops them
-  * It keeps your system healthy automatically
+  * Restarts them when they fail
+  * Scales them up or down
+===== Concepts category =====
-===== Key idea =====
-Kubernetes is a **container orchestration system**.
-It handles:
+  * Cluster Fundamentals
-  * Starting containers
+    * Cluster
-  * Stopping unhealthy containers
+    * Control Plane
-  * Scaling up/down
+    * Node
-  * Networking between containers
+    * Namespace
-  * Service discovery
-===== Simple analogy =====
+  * Workloads (Run Applications)
-Think of Kubernetes as a **traffic controller**:
+    * Pod
-  * Containers = cars
+    * ReplicaSet
-  * Nodes = roads
+    * Deployment
-  * Kubernetes = traffic system that ensures everything flows correctly
+    * StatefulSet
+    * DaemonSet
+    * Job
+    * CronJob
+  * Networking
+    * Service
+      * ClusterIP
+      * NodePort
+      * LoadBalancer
+      * ExternalName
+    * Ingress
+    * Ingress Controller
+    * NetworkPolicy
+  * Configuration
+    * ConfigMap
+    * Secret
+  * Storage
+    * PersistentVolume (PV)
+    * PersistentVolumeClaim (PVC)
+    * StorageClass
+    * Volume
+  * Security
+    * ServiceAccount
+    * RBAC
+      * Role
+      * RoleBinding
+      * ClusterRole
+      * ClusterRoleBinding
+    * SecurityContext
+    * Pod Security
+  * Scheduling
+    * NodeSelector
+    * Node Affinity
+    * Pod Affinity
+    * Pod Anti-Affinity
+    * Taints
+    * Tolerations
+  * Autoscaling
+    * Horizontal Pod Autoscaler (HPA)
+    * Vertical Pod Autoscaler (VPA)
+    * Cluster Autoscaler
+  * Observability
+    * Logs
+    * Metrics
+    * Traces
+    * Prometheus
+    * Grafana
+    * Loki
+    * Jaeger
+  * Configuration Management
+    * Helm
+    * Kustomize
+    * Operators
+  * Ecosystem / Operations
+    * CI/CD
+      * GitHub Actions
+      * GitLab CI
+      * ArgoCD
+    * Container Runtime
+      * containerd
+      * CRI-O
+    * Service Mesh
+      * Istio
+      * Linkerd
+    * Cloud Providers
+      * Amazon EKS
+      * Google GKE
+      * Azure AKS
+      * DigitalOcean DOKS
+===== Simple explanation =====
+Kubernetes = "automated container manager"
+---
+===== Real-world example =====
+Imagine you have a web application:
-===== Core value =====
 Without Kubernetes:
-  * You manage containers manually
+  * You run Docker containers manually
+  * If one crashes → you restart it yourself
+  * If traffic increases → you manually add more containers
 With Kubernetes:
-  * The system manages itself based on your desired state
+  * You define: "I want 3 instances running"
+  * Kubernetes ensures 3 instances are always running
+  * If one crashes → it automatically replaces it
+  * If traffic increases → it can add more instances automatically
+---
+===== Simple analogy =====
+Kubernetes is like a **restaurant manager**:
+  * You (developer) define the menu (desired state)
+  * Kubernetes ensures chefs (containers) are always available
+  * If a chef leaves → it hires a new one automatically