Kubernetes on Raspberry Pi with Ansible - Usage Guide

This guide details how to use the generated Ansible playbook to install Kubernetes on your Raspberry Pi cluster.

Prerequisites

Ansible Installed: You need Ansible installed on your control machine (your laptop/desktop).

Debian/Ubuntu:

sudo apt update && sudo apt install ansible sshpass -y

Arch Linux:
```
sudo pacman -S ansible sshpass
```
Fedora:
```
sudo dnf install ansible sshpass
```

SSH Access: Ensure you have SSH access to all Raspberry Pi nodes.
Hardware: 4 Raspberry Pi nodes (1 Master, 3 Workers) with Raspberry Pi OS installed.

Configuration Steps

1. Configure Inventory

Edit inventory/hosts.ini and replace the placeholder IP addresses with the actual IPs of your Raspberry Pis.

[masters]
pi1 ansible_host=192.168.1.10  <-- Change to Master IP

[workers]
pi2 ansible_host=192.168.1.11  <-- Change to Worker 1 IP
pi3 ansible_host=192.168.1.12  <-- Change to Worker 2 IP
pi4 ansible_host=192.168.1.13  <-- Change to Worker 3 IP

2. Configure Credentials

You need to set the SSH password for the pi user. We use Ansible Vault for security.

Generate an encrypted password string:
```
ansible-vault encrypt_string 'YOUR_ACTUAL_PASSWORD' --name 'vault_ssh_password'
```
Replace YOUR_ACTUAL_PASSWORD with the real password.
Copy the output block and paste it into group_vars/all.yml, replacing the commented out section or just adding it.

Example in group_vars/all.yml:
```
ansible_password: !vault |
          $ANSIBLE_VAULT;1.1;AES256
          ... (encrypted string) ...
```
Do the same for vault_become_password if your sudo password is different. If sudo password is same as ssh password, you can just set:
```
ansible_become_password: "{{ vault_ssh_password }}"
```

3. Run the Playbook

To start the installation, run:

ansible-playbook site.yml --ask-vault-pass

Note: Since you used encrypt_string without a password file, it might ask for a vault password if you set one. If you just used encrypt_string, you might need to provide the vault password you used to encrypt it.

Alternative (Simpler for testing): If you don't want to use Vault yet, you can pass the password as an extra var (INSECURE - be careful with history):

ansible-playbook site.yml -e "ansible_password=yourpassword ansible_become_password=yourpassword"

Verification

After the playbook completes:

SSH into the Master Node:
```
ssh pi@<master-ip>
```
Check Nodes:
```
kubectl get nodes
```
You should see 4 nodes with status Ready.
Check Pods:
```
kubectl get pods -A
```
Ensure coredns and kube-flannel are running.

Kubernetes Dashboard

A dashboard has been installed and is accessible via NodePort on the master node.

Get the Token: Run this command on the master node to get your login token:

kubectl get secret admin-user-token -n kubernetes-dashboard -o jsonpath={".data.token"} | base64 -d

Access the Dashboard: Open your browser and navigate to: https://<master-ip>:30443

Note: Since it uses a self-signed certificate, you will need to bypass the browser security warning (usually click "Advanced" -> "Proceed").