From a02861266961dd552bfbe5db0440f7091471ee33 Mon Sep 17 00:00:00 2001
From: root <pirouz.radin@yahoo.com>
Date: Sun, 22 Jun 2025 21:59:29 +0330
Subject: [PATCH] update kuber doc

---
 .../Kubernetes/1-Information.md               |  97 ++++++----
 .../Kubernetes/2-Installtion.md               | 180 +++++++++++++-----
 2 files changed, 194 insertions(+), 83 deletions(-)

diff --git a/Containerization & Orchestration/Kubernetes/1-Information.md b/Containerization & Orchestration/Kubernetes/1-Information.md
index aca5679..f2b5cc9 100755
--- a/Containerization & Orchestration/Kubernetes/1-Information.md	
+++ b/Containerization & Orchestration/Kubernetes/1-Information.md	
@@ -1,65 +1,82 @@
-# Kubernetes (K8s) Documentation
+# 🚢 Kubernetes (K8s) Documentation
 
-## Overview  
+## 🌐 Overview
 **Kubernetes (K8s)** is an open-source container orchestration platform designed to automate the deployment, scaling, and operation of containerized applications.
 
 ---
 
-## Control Plane (CP)  
-The **Control Plane** is the core management component of a Kubernetes cluster. It makes global decisions about the cluster (e.g., scheduling), and it maintains the desired state of the cluster by managing workloads and directing communication within the system.  
-> **Note:** By default, the Control Plane does not directly manage or run application containers.
+## 🧠 Control Plane (CP)
+The **Control Plane** is the core management component of a Kubernetes cluster. It makes global decisions about the cluster (e.g., scheduling) and maintains the desired state of the cluster by managing workloads and directing communication within the system.
 
-### Key Components of the Control Plane:
-- **API Server (`kube-apiserver`)**:  
-  Exposes the Kubernetes API and serves as the entry point to the cluster. It handles communication between internal components and external clients.
-  
-- **Scheduler (`kube-scheduler`)**:  
-  Assigns work (e.g., pods) to nodes based on resource availability and policies.
+> 💡 **Note:** By default, the Control Plane does not directly manage or run application containers.
 
-- **Controller Manager (`kube-controller-manager`)**:  
-  Runs controllers that regulate the state of the cluster (e.g., Node Controller, Replication Controller, etc.).
+### 🔑 Key Components of the Control Plane
 
-- **etcd**:  
-  A consistent, highly-available key-value store that stores all cluster data, configurations, and states. This is the "database" of Kubernetes.
+- **API Server (`kube-apiserver`)**  
+  Exposes the Kubernetes API and serves as the cluster's entry point. It handles communication between internal components and external clients.
+
+- **Scheduler (`kube-scheduler`)**  
+  Assigns workloads (e.g., Pods) to nodes based on resource availability and defined policies.
+
+- **Controller Manager (`kube-controller-manager`)**  
+  Runs controllers that monitor and regulate the cluster's state, such as the Node Controller and Replication Controller.
+
+- **etcd**  
+  A consistent and highly available key-value store that stores all cluster data, configurations, and state. This is the "database" of Kubernetes.
 
 ---
 
-## Worker Nodes  
-Worker nodes are the machines where containerized applications run. Each worker node contains essential components for managing containers.
+## 🧱 Worker Nodes
+**Worker nodes** are the machines where containerized applications run. Each node contains essential components for managing containers.
 
-### Key Components of a Worker Node:
-- **Kubelet**:  
-  An agent that ensures containers are running as specified in their Pod definitions. It communicates with the Control Plane to receive and execute tasks.
+### 🔧 Key Components of a Worker Node
 
-- **Kube Proxy**:  
-  Maintains network rules and handles routing for communication between services within the cluster and with external traffic.
+- **Kubelet**  
+  An agent that ensures containers run as specified in their Pod definitions. It communicates with the Control Plane to execute assigned tasks.
+
+- **Kube Proxy**  
+  Maintains network rules and manages routing for communication within the cluster and with external systems.
 
 ---
 
-## Data Flow  
-- **Kubelet** and **Kube Proxy** on each worker node communicate with the **API Server** in the Control Plane for task execution and resource updates.
-- The **Scheduler** assigns pods to nodes based on resource requirements, while the **Controller Manager** ensures that the cluster state remains consistent.
+## 🔄 Data Flow
+- **Kubelet** and **Kube Proxy** on each worker node interact with the **API Server** to perform operations and update resource states.
+- The **Scheduler** selects suitable nodes for pod placement based on available resources.
+- The **Controller Manager** ensures the actual state of the cluster matches the desired state.
 
 ---
 
-## Administration Tools  
-- **`kubeadm`**:  
-  A tool for bootstrapping Kubernetes clusters. It simplifies the setup and configuration of the Control Plane and worker nodes.
+## 🛠️ Administration Tools
 
-- **`kubectl`**:  
-  The command-line interface (CLI) for interacting with the Kubernetes API. It is used to manage resources, deploy applications, and inspect cluster components.
+- **`kubeadm`**  
+  A command-line tool to bootstrap and configure Kubernetes clusters. It streamlines the setup of both the Control Plane and worker nodes.
+
+- **`kubectl`**  
+  The CLI for interacting with the Kubernetes API. It's used to deploy apps, inspect cluster resources, and manage configurations.
 
 ---
 
-## Kubernetes Version Compatibility  
-### Kubernetes and Container Runtimes:
-- **Kubernetes ≤ 1.23**:  
-  Compatible with Docker as the default container runtime.
-  
-- **Kubernetes 1.24 to 1.25**:  
-  Docker is not supported as a runtime. These versions require `containerd` or another Container Runtime Interface (CRI) implementation.
-  
-- **Kubernetes ≥ 1.25**:  
-  Docker can be installed on the server but must be used indirectly through `containerd` or another CRI-compliant runtime. Docker itself is not a supported runtime.
+## 🧩 Kubernetes Version Compatibility
 
+### Kubernetes and Container Runtimes
 
+- **Kubernetes ≤ 1.23**  
+  ✅ Compatible with **Docker** as the default container runtime.
+
+- **Kubernetes 1.24 – 1.25**  
+  ❌ Docker is **not supported** directly. Use `containerd` or another CRI-compliant runtime.
+
+- **Kubernetes ≥ 1.25**  
+  ⚠️ Docker may be installed on the system but must be used **indirectly** through `containerd` or another supported CRI.
+
+---
+
+## 👥 Kubernetes Roles
+
+- **Control Plane (Manager)**  
+  Requires an **odd number** of nodes for high availability (e.g., 1, 3, 5, ...). This ensures quorum in distributed consensus.
+
+- **Worker (none)**  
+  These nodes run application workloads and do not participate in control decisions.
+
+---
diff --git a/Containerization & Orchestration/Kubernetes/2-Installtion.md b/Containerization & Orchestration/Kubernetes/2-Installtion.md
index 130dba3..d7fc5b7 100755
--- a/Containerization & Orchestration/Kubernetes/2-Installtion.md	
+++ b/Containerization & Orchestration/Kubernetes/2-Installtion.md	
@@ -1,67 +1,161 @@
+# 🐳 Containerd and Kubernetes Installation Guide
+
+A comprehensive step-by-step guide for setting up a Kubernetes cluster using **Containerd** as the container runtime. This guide is intended for Ubuntu-based systems.
 
 ---
 
-# Containerd and Kubernetes Installation Guide
+## ⚙️ 1. Disable Swap
 
-## 1. Disable Swap
-Turn off swap and disable it permanently.
+Kubernetes requires swap to be disabled for proper scheduling and memory management.
 
 ```bash
-swapoff -a
-sed -i '/swap/d' /etc/fstab
+sudo swapoff -a
+sudo sed -i '/swap/d' /etc/fstab
 ```
-## 2. Enable Required Kernel Modules
-Create a configuration file to load necessary kernel modules and load them temporarily.
+
+---
+
+## 🧩 2. Enable Required Kernel Modules
+
+Load the necessary kernel modules for networking and overlay file systems.
+
 ```bash
-echo -e "overlay\nbr_netfilter" | sudo tee /etc/modules-load.d/containerd.conf
+cat <<EOF | sudo tee /etc/modules-load.d/containerd.conf
+overlay
+br_netfilter
+EOF
+
 sudo modprobe overlay
 sudo modprobe br_netfilter
 ```
-## 3. Enable IPv4 Forwarding
-Enable IPv4 forwarding in the sysctl configuration and apply the changes.
+
+---
+
+## 🌐 3. Enable IPv4 Forwarding
+
+Enable packet forwarding to allow pods to communicate across the network.
+
 ```bash
-sed -i 's/#net.ipv4.ip_forward=1/net.ipv4.ip_forward=1/' /etc/sysctl.conf
-sysctl -p
-```
-## 4. Configure Containerd
-Generate the default configuration for Containerd and modify it to use systemd as the cgroup driver.
-```bash
-containerd config default | sudo tee /etc/containerd/config.toml
-sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml
+sudo tee /etc/sysctl.d/99-kubernetes-cri.conf <<EOF
+net.bridge.bridge-nf-call-iptables  = 1
+net.ipv4.ip_forward                 = 1
+net.bridge.bridge-nf-call-ip6tables = 1
+EOF
+
+sudo sysctl --system
 ```
 
-## 5. Install Kubernetes
-Add the Kubernetes package repository and install the required packages.
+---
+
+## 📦 4. Install and Configure Containerd
+
+Install and configure **Containerd** with `systemd` as the cgroup driver.
+
+```bash
+sudo apt-get update && sudo apt-get install -y containerd
+
+sudo mkdir -p /etc/containerd
+containerd config default | sudo tee /etc/containerd/config.toml
+
+sudo sed -i 's/SystemdCgroup = false/SystemdCgroup = true/' /etc/containerd/config.toml
+
+sudo systemctl restart containerd
+sudo systemctl enable containerd
+```
+
+---
+
+## ⎈ 5. Install Kubernetes Components
+
+Add the Kubernetes repository and install the core components: `kubelet`, `kubeadm`, and `kubectl`.
+
 ```bash
 sudo mkdir -p /etc/apt/keyrings
 curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
-echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
+
+echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /" | sudo tee /etc/apt/sources.list.d/kubernetes.list
+
 sudo apt-get update
 sudo apt-get install -y kubelet kubeadm kubectl
 sudo apt-mark hold kubelet kubeadm kubectl
 ```
-## 6. Enable kubelet
-Enable and start the kubelet service.
-```bash
-sudo systemctl enable --now kubelet
-```
-## 7. Initialize the Kubernetes Cluster
-Initialize the Kubernetes control plane with the specified parameters.
-```bash
-sudo kubeadm init --control-plane-endpoint 192.168.2.100 --apiserver-advertise-address 192.168.2.100 --pod-network-cidr 10.244.0.0/16 | tee kuber-install.log
-```
-## 8. Create Control Plane Join Command
-Create the control plane join command and save it for later use.
-```bash
-sudo kubeadm init phase upload-certs --upload-certs
-
-Copy the output certificate key and run the following command, replacing <CERTIFICATE_KEY> with the copied key.
-
-sudo kubeadm token create --certificate-key <CERTIFICATE_KEY> --print-join-command | tee cp-command.txt
-```
-## 9. Join Control Plane and Worker Nodes
-Use the command from cp-command.txt on your control plane nodes to join them. Additionally, get the join command for worker nodes from kuber-install.log and run it on each worker node.
 
 ---
 
-This revised guide provides clear, step-by-step instructions, making it easier to follow and ensuring all necessary actions are covered.
\ No newline at end of file
+## 🔁 6. Enable Kubelet Service
+
+Start and enable the kubelet to run on system boot.
+
+```bash
+sudo systemctl enable --now kubelet
+```
+
+---
+
+## 🚀 7. Initialize the Kubernetes Control Plane
+
+Initialize the cluster. Replace the IP with your master node's IP address.
+
+```bash
+sudo kubeadm init \
+  --control-plane-endpoint 192.168.2.100 \
+  --apiserver-advertise-address 192.168.2.100 \
+  --pod-network-cidr 10.244.0.0/16 | tee kuber-install.log
+```
+
+---
+
+## 🛠 8. Configure kubectl Access
+
+Set up `kubectl` for the current (non-root) user.
+
+```bash
+mkdir -p $HOME/.kube
+sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
+sudo chown $(id -u):$(id -g) $HOME/.kube/config
+```
+
+---
+
+## 🧾 9. Create Control Plane Join Command
+
+Generate a command for other control plane nodes to join the cluster.
+
+```bash
+sudo kubeadm init phase upload-certs --upload-certs
+```
+
+Copy the **certificate key** from the output above and run:
+
+```bash
+sudo kubeadm token create --certificate-key <CERTIFICATE_KEY> --print-join-command | tee cp-command.txt
+```
+
+Replace `<CERTIFICATE_KEY>` with the actual key.
+
+---
+
+## 🧑‍🤝‍🧑 10. Join Control Plane and Worker Nodes
+
+* **Control Plane Nodes**: Use the command from `cp-command.txt` on each node.
+* **Worker Nodes**: Use the `kubeadm join` command printed at the end of the `kubeadm init` output or found in `kuber-install.log`.
+
+---
+
+## ✅ Final Step: Install a Pod Network Add-on
+
+Choose and apply a pod network add-on (e.g., Flannel, Calico, Cilium). Here's an example with Flannel:
+
+```bash
+kubectl apply -f https://raw.githubusercontent.com/flannel-io/flannel/master/Documentation/kube-flannel.yml
+```
+
+---
+
+🎉 **Your Kubernetes cluster is now up and running!**
+Ensure all nodes are ready by running:
+
+```bash
+kubectl get nodes
+```
+