Android K3s Worker Node Project

Turn your old Android devices into productive Kubernetes worker nodes using K3s.

Project Manifesto

The goal of this project is to democratize edge computing by upcycling consumer electronics. Billions of "obsolete" Android phones sit in drawers, possessing powerful ARM CPUs, built-in battery backups (UPS), and WiFi connectivity. We bypass the restrictive Android ecosystem (which blocks standard Linux setups) using techniques like Termux (Proot) or Chroot environments, effectively layering a GNU/Linux userspace over the Android kernel to run container orchestrators like K3s.

Critical Analysis

Feature	Pros	Cons
Power	Built-in Battery (UPS) - survive outages	Thermal Throttling under 24/7 load
Compute	Decent ARM64 cores (often 8-core)	Limited RAM (2GB-4GB common)
Network	WiFi builtin	Latency usage; no native Ethernet often
OS/Kernel	Already installed	Missing cgroups/modules; "Franken-kernel"

In-Depth Directory Structure

This repository contains the "Golden" setup kit for your node.

k3s-server/
├── README.md                 # This blueprint
├── scripts/
│   └── setup-node.sh         # The 'Golden' setup script to fix cgroups & env
└── config/
    └── k3s-agent-config.yaml # Low-power optimized agent configuration
├── demo-app/                 # Production-ready Go reference implementation
│   ├── Dockerfile            # Multi-stage, distroless, non-root optimized
│   ├── deployment.yaml       # K8s manifest with probes & limits
│   └── main.go               # Sample app with graceful shutdown

Production Reference: Demo App

The demo-app/ directory contains a "Gold Standard" reference implementation for running workloads on your new Android nodes. It is critical for these resource-constrained devices that applications are optimized.

Key Features:

• Zero-Fat Images: Uses multi-stage builds and distroless base images to keep containers under 20MB.
• Safety First: Runs as a non-root user to protect the host node.
• Resanable Defaults: Includes Liveness/Readiness probes and Memory/CPU limits to prevent node crashes.

Use this directory as a template for your own applications.

User Journey: From Drawer to Node

Follow this guide to convert your device.

Phase 1: Preparation

1. Unlock & Root: Your Android device must be rooted to mount cgroups and manage networking.
2. Linux Environment: Install Linux Deploy (recommended for beginners) or set up a Termux root shell.
   • Tip: Use a lightweight distro like Alpine or Ubuntu Server.
3. SSH Access: Ensure you can SSH into the device from your PC.

Phase 2: Copy Files

Transfer this project folder to your Android device (e.g., via scp or git clone).

scp -r k3s-server user@android-ip:~/

Phase 3: The Golden Setup

Run the automated setup script to patch the environment.

cd k3s-server/scripts
sudo chmod +x setup-node.sh
sudo ./setup-node.sh

This script will fix the missing cgroup hierarchies that usually cause K3s to fail on Android.

Phase 4: Ignite the Node

Join the node to your existing K3s cluster.

Important: You must have a K3s Master running first. See k8s-install/README.md for master setup instructions.

Once you have your K3S_TOKEN and K3S_URL from the master:

# Set your server details
export K3S_URL="https://192.168.1.100:6443"
export K3S_TOKEN="K10..."

# Install and start using the optimized config
curl -sfL https://get.k3s.io | sh -s - agent \
  --config ../config/k3s-agent-config.yaml

Phase 5: Verify

On your server node, run:

kubectl get nodes

You should see your Android device listed as Ready with the label device_type=android.

Phase 6: Run the Demo App

Validate your new node's capabilities by deploying the included production-ready reference application.

kubectl apply -f demo-app/deployment.yaml
# Verification
kubectl get pods -o wide
# You should see the pod running on your Android node!