aula-07 e aula-08: Cluster Talos HA na Hetzner com Autoscaler

aula-07: Criação de imagem Talos customizada na Hetzner Cloud
- Usa Talos Factory para gerar imagem ARM64/AMD64
- Inclui extensões: qemu-guest-agent, hcloud

aula-08: Provisionamento de cluster Kubernetes Talos via OpenTofu
- 3 Control Planes em HA (CAX11 ARM64)
- 1 Worker Node (CAX11 ARM64)
- Rede privada, Floating IP, Firewall
- Cluster Autoscaler para Hetzner (0-5 workers extras)
- Setup interativo com validação de pré-requisitos
- Custo estimado: ~€18/mês (base)

Também inclui:
- .gitignore para ignorar arquivos sensíveis
- CLAUDE.md com instruções do projeto

CLAUDE.md

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+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is a workshop repository for teaching Docker and Kubernetes concepts, specifically focusing on container health checks and liveness probes. It contains a deliberately "buggy" Node.js app that hangs after a configurable number of requests to demonstrate how container orchestration handles unhealthy containers.
+
+## Repository Structure
+
+- **aula-01/**: Docker Compose lesson - basic container deployment with restart policies
+- **aula-02/**: Kubernetes lesson - deployment with liveness probes and ConfigMaps
+- **aula-03/**: Kubernetes lesson - high availability with replicas and readiness probes
+- **aula-04/**: Kubernetes lesson - NGINX Ingress with Keep Request (Lua) for zero-downtime
+- **aula-05/**: Kubernetes lesson - KEDA + Victoria Metrics for metrics-based auto-scaling
+- **aula-06/**: Kubernetes lesson - n8n deployment via Helm with Queue Mode (workers, webhooks, PostgreSQL, Redis)
+- **aula-07/**: Talos Linux - creating custom Talos image for Hetzner Cloud
+- **aula-08/**: OpenTofu - provisioning HA Talos Kubernetes cluster on Hetzner Cloud
+
+## Running the Examples
+
+### Aula 01 (Docker Compose)
+```bash
+cd aula-01
+docker-compose up
+```
+The app runs on port 3000. After MAX_REQUESTS (default 3), the app stops responding.
+
+### Aula 02 (Kubernetes)
+```bash
+cd aula-02
+kubectl apply -f configmap.yaml
+kubectl apply -f deployment.yaml
+kubectl apply -f service.yaml
+```
+Access via NodePort 30080. The liveness probe at `/health` will detect when the app hangs and restart the container.
+
+### Aula 03 (Kubernetes - High Availability)
+```bash
+cd aula-03
+kubectl apply -f configmap.yaml
+kubectl apply -f deployment.yaml
+kubectl apply -f service.yaml
+```
+Builds on Aula 02 with multiple replicas and a readiness probe. When one pod hangs, the others continue serving requests. The readiness probe removes unhealthy pods from the Service immediately, while the liveness probe restarts them.
+
+### Aula 04 (Kubernetes - NGINX Ingress with Keep Request)
+Requires NGINX Ingress Controller with Lua support.
+
+```bash
+cd aula-04
+kubectl apply -f configmap.yaml
+kubectl apply -f deployment.yaml
+kubectl apply -f service.yaml
+kubectl apply -f ingress-nginx.yaml
+```
+Access via NGINX Ingress. The Keep Request pattern uses Lua to hold requests when backends are unavailable, waiting up to 99s for a pod to become ready instead of returning 503 immediately. This eliminates user-visible failures during pod restarts.
+
+### Aula 05 (Kubernetes - KEDA Auto-scaling)
+```bash
+cd aula-05
+./setup.sh
+```
+Installs Victoria Metrics (metrics collection), KEDA (event-driven autoscaling), and NGINX Ingress. The ScaledObject monitors metrics like unavailable pods and restart counts, automatically scaling the deployment from 5 to 30 replicas based on demand.
+
+### Aula 06 (Kubernetes - n8n via Helm)
+```bash
+cd aula-06
+./setup.sh
+```
+Deploys n8n workflow automation platform via Helm chart with Queue Mode architecture: main node, workers (2-5 replicas with HPA), webhooks (1-3 replicas with HPA), PostgreSQL, and Redis. Access via http://n8n.localhost (requires NGINX Ingress).
+
+### Aula 07 (Talos Linux - Custom Image)
+Follow the instructions in `aula-07/README.md` to create a custom Talos Linux image on Hetzner Cloud using Talos Factory. This is a prerequisite for Aula 08.
+
+### Aula 08 (OpenTofu - Talos Cluster on Hetzner Cloud)
+```bash
+cd aula-08
+./setup.sh
+```
+Provisions a full HA Kubernetes cluster on Hetzner Cloud using OpenTofu:
+- 3x Control Plane nodes (CAX11 ARM64)
+- 1x Worker node (CAX11 ARM64)
+- Private network, Floating IP, Firewall
+- Cluster Autoscaler support (1-5 workers)
+- Estimated cost: ~€18/month (base), up to ~€33/month with max autoscaling
+
+Prerequisites:
+- OpenTofu (`brew install opentofu`)
+- talosctl (`brew install siderolabs/tap/talosctl`)
+- kubectl
+- Hetzner Cloud API token
+- Talos image ID from Aula 07
+
+Optional - Enable cluster autoscaling:
+```bash
+./install-autoscaler.sh
+```
+This installs the Kubernetes Cluster Autoscaler configured for Hetzner Cloud, automatically scaling workers from 1 to 5 based on pending pods.
+
+To destroy the infrastructure: `./cleanup.sh`
+
+## App Behavior
+
+The Node.js app (`app.js`) is intentionally designed to:
+1. Accept requests normally until `MAX_REQUESTS` is reached
+2. Stop responding (hang) after the limit, simulating a crashed but running process
+3. The `/health` endpoint also stops responding when the app is "stuck"
+
+This behavior demonstrates why process-level monitoring (restart: always) is insufficient and why application-level health checks (liveness probes) are necessary.
+
+## Environment Variables
+
+- `MAX_REQUESTS`: Number of requests before the app hangs (default: 3)