Kubernetes: Folder Structure and Functionality Overview

Kubernetes directory structure includes /etc/kubernetes/ for main configuration files, /etc/kubernetes/manifests/ for YAML files of system components, /etc/kubernetes/pki for PKI files, /etc/cni/net.d/ for CNI plugin configs, /var/lib/kubelet/ for pod data and YAML file of kubelet, and /opt/cni/bin/ for CNI plugin binaries.

Kubernetes: Folder Structure and Functionality Overview

Here’s an overview of the folder structure of a Kubernetes cluster and its functionality:

/etc/kubernetes/
├── manifests/                       # YAML files defining Kubernetes resources
│   ├── etcd.yaml                    # etcd cluster manifest
│   ├── kube-apiserver.yaml          # kube-apiserver manifest
│   ├── kube-controller-manager.yaml # kube-controller-manager manifest
│   ├── kube-scheduler.yaml          # kube-scheduler manifest
│   ├── kube-proxy.yaml              # kube-proxy manifest
│   └── ...
├── pki/                             # Public Key Infrastructure for Kubernetes
│   ├── apiserver.crt                # Kubernetes API Server certificate
│   ├── apiserver.key                # Kubernetes API Server private key
│   ├── ca.crt                       # Cluster Certificate Authority certificate
│   ├── ca.key                       # Cluster Certificate Authority private key
│   └── ...
├── kubelet.conf                     # kubelet configuration file
├── controller-manager.conf          # kube-controller-manager configuration file
├── scheduler.conf                   # kube-scheduler configuration file
└── admin.conf                       # kubeconfig file for cluster administrator

/etc/cni/net.d/                      # Folder containing CNI configuration files

/var/lib/kubelet/
├── pods/                            # Directory containing pod volumes and data
├── pki/                             # Public Key Infrastructure for kubelet
├── config.yaml                      # kubelet manifest
└── ...

/opt/cni/bin/                        # Container Networking Interface (CNI) binaries

1. /etc/kubernetes/: This folder contains the main configuration files for the Kubernetes control plane components.
2. /etc/kubernetes/manifests/: This folder contains the YAML files for the Kubernetes system components that run as pods.
3. /etc/kubernetes/pki/: This folder contains the public key infrastructure (PKI) files that are used for secure communication between the different components of the Kubernetes cluster.
4. /etc/cni/net.d/: This folder contains the configuration files for Container Networking Interface (CNI) plugins used by Kubernetes to manage networking.
5. /var/lib/kubelet/: This folder contains the actual data and volumes associated with each pod, as well as the config.yaml file for the kubelet.
6. /opt/cni/bin: This folder contains the binary files for CNI plugins used by Kubernetes.

These are my personal notes for CKA exam preparation on Kubernetes. Please feel free to correct me if you notice any errors. 😊