☸️ Kubernetes & Containers Interactive Digital Textbook & Simulator

A 100% self-contained, highly visual, explorable digital textbook and interactive simulator designed to demystify Kubernetes architecture, container networking, scheduling algorithms, and cluster resiliency for beginners and certification candidates.

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🌟 Interactive Simulators Included

1. 🌐 Multi-Tier Request Lifecycle & Wireshark Dissector

• 3 Dynamic Traffic Scenarios:
  • Cloud LoadBalancer & NodePort (:31456)
  • L7 Ingress Controller (Host/Path Routing)
  • East-West Microservice (Intra-cluster Pod-to-Pod VIP via CoreDNS)
• Live Wireshark-Style Packet Dissector: Layer 3 (IP), Layer 4 (TCP), Layer 7 (HTTP URI & Headers), and NAT state.
• Kernel iptables / IPVS Translation Table: Real-time PREROUTING and DNAT rule matching with chosen pod IPs.
• Pod Fault Modifiers: Readiness probe fail toggle (pulled from EndpointSlice) and HTTP 500 error injection.
• 10-Orb Burst Stream & Speed Controls: Slow-Mo (0.5x), Normal (1.0x), and Fast (2.0x).

2. 🗂️ Dual-View Topology & Reactive Cluster Scaling Sandbox

• Replica Stepper (1 to 6 Pods): Dynamically scales workloads and places them on physical worker nodes.
• Anti-Affinity Constraint Enforcement: Spreads 1 pod per physical VM; marks surplus pods as Pending.
• Hardware Capacity Gauges: Real-time CPU and RAM allocation meters per worker node.
• Twin Pod Cross-Link Highlighting: Hovering over any logical pod highlights its physical VM host.

3. ⚙️ Scheduler Decision Engine (Filter & Score Playground)

• Configurable Pod Specifications: CPU requests, RAM requests, NodeSelectors (disk=ssd, region=us-east), and GPU Tolerations.
• Stage 1 (Predicates / Filtering): Evaluates candidate nodes with stamped disqualification rationale.
• Stage 2 (Priorities / Scoring): Ranks surviving nodes with resource balance and Image Locality bonuses.
• Binding & CRI Stream: Winner trophy assignment and simulated containerd gRPC socket calls.

4. 💥 Cluster Failure & Chaos Engineering Sandbox

• 8 Outage Scenarios:
  • CrashLoopBackOff (Exponential backoff 10s -> 20s)
  • OOMKilled (Memory cgroup limit exceeded, Exit 137)
  • Readiness Failure (Endpoints exclusion)
  • Liveness Failure (Forced container kill & restart)
  • Worker Node Power Loss (Heartbeat timeout & pod eviction)
  • Node Drain (kubectl drain)
  • Control Plane Outage (Proves data plane survivability)
• Automated Chaos Monkey: Fault injection loop with live SLA uptime percentage.
• Dual-Tab CLI Output: $ kubectl get pods -o wide and $ kubectl describe & events.

5. 🧠 10-Card Spaced Repetition Misconception Buster Deck

• 10 exam-grade Kubernetes misconceptions covering Services, Deployments, NodePorts, Pause container namespaces, ephemeral IPs, and resource limits.
• Spaced repetition self-rating (Needs Review vs Mastered ✓) with localStorage persistence.
• Category filters: All, Networking, Architecture, and Workloads.

6. 📝 Diagnostic Knowledge Check & 30-Term CLI Reference

• Diagnostic scenario-based quiz with instant feedback and chapter remediation links.
• 30-term searchable glossary with 1-click copyable kubectl cheat-sheet commands.

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🚀 Quick Start (Zero Build Steps)

No Node.js, npm, or build tools are required. Simply open index.html in any modern web browser:

# Clone the repository
git clone https://github.com/akshaycolombus/Kubernetes_Containers_Simulator.git

# Navigate into the project
cd Kubernetes_Containers_Simulator

# Open in default browser (Windows)
start index.html

# Open in default browser (macOS)
open index.html

# Open in default browser (Linux)
xdg-open index.html

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🎨 Design System & Technologies

• Design Framework: Tailwind CSS (via CDN).
• Typography: Inter (UI) & JetBrains Mono (Code/CLI) via Google Fonts.
• Iconography: FontAwesome 6.4.
• Vector Graphics: Dynamic SVG cubic bezier network cables.
• Physics Engine: Vanilla JavaScript hardware-accelerated transforms.
• Storage: Browser localStorage for quiz scores and flashcard mastery.

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📄 License

MIT License. Open source for educators, students, and engineers.