🎮 Multiplayer AAA Game Server Architecture on AWS

A Global, Managed, and High-Performance backend infrastructure for hosting multiplayer game servers on AWS. Built with Terraform (IaC), Amazon GameLift Container Fleets (managed game server hosting), and CI/CD automation via GitHub Actions.

Note: This is a portfolio/demo project. The game server simulates player connections and state management to demonstrate the full infrastructure stack working end-to-end.

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🏗️ Architecture Overview

Key Components:

Layer	Components
Deployment Pipeline	GitHub → GitHub Actions → Build Docker → Push to ECR → Update GameLift Fleet
Networking	VPC with public/private subnets across 2 AZs, NLB for game traffic
Compute	Amazon GameLift Container Fleets (On-Demand, managed placement)
Storage	S3 (versioned game assets), DynamoDB (player state + leaderboard)
Container Registry	Amazon ECR (game server + init container images)

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📁 Project Structure

multiplayer-game-server-aws/
├── terraform/                    # Infrastructure as Code
│   ├── modules/
│   │   ├── vpc/                  # VPC, subnets, NAT, IGW, GameLift SG
│   │   ├── gamelift/             # Container Fleet, Container Group, IAM, scaling
│   │   ├── ecr/                  # Container registries
│   │   ├── s3/                   # Game asset storage
│   │   └── dynamodb/             # Player state database
│   ├── environments/
│   │   ├── dev/                  # Dev environment (1 instance, c5.large)
│   │   └── prod/                 # Prod environment (2+ instances, c5.xlarge)
│   └── backend.tf                # S3 + DynamoDB state backend
├── gamelift/                     # GameLift Container Definitions
│   ├── container-group-definition.json
│   ├── fleet-config-dev.json
│   └── fleet-config-prod.json
├── game-server/                  # Demo game server application
│   ├── src/server.js             # Node.js UDP/TCP/HTTP server
│   ├── Dockerfile                # Multi-stage production build
│   └── init-container/           # S3 asset sync container
├── .github/workflows/
│   ├── ci.yaml                   # PR checks: lint, validate, plan, build
│   └── cd.yaml                   # Deploy: build, push ECR, update GameLift
└── README.md

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🚀 Quick Start

Prerequisites

Tool	Version	Install
AWS CLI	v2+	Install Guide
Terraform	v1.10+	Install Guide
Docker	v24+	Install Guide

Step 1: Bootstrap the Terraform Backend

# Create S3 bucket for Terraform state
aws s3api create-bucket \
  --bucket game-server-terraform-state \
  --region eu-west-2 \
  --create-bucket-configuration LocationConstraint=eu-west-2

# Enable versioning on the state bucket
aws s3api put-bucket-versioning \
  --bucket game-server-terraform-state \
  --versioning-configuration Status=Enabled

# Create DynamoDB table for state locking
aws dynamodb create-table \
  --table-name terraform-state-lock \
  --attribute-definitions AttributeName=LockID,AttributeType=S \
  --key-schema AttributeName=LockID,KeyType=HASH \
  --billing-mode PAY_PER_REQUEST \
  --region eu-west-2

Step 2: Deploy Infrastructure

cd terraform/environments/dev
terraform init
terraform plan -var-file=terraform.tfvars
terraform apply -var-file=terraform.tfvars

Step 3: Build & Push Docker Images

# Login to ECR
aws ecr get-login-password --region eu-west-2 | \
  docker login --username AWS --password-stdin \
  $(terraform output -raw game_server_ecr_url | cut -d/ -f1)

# Build and push game server
docker build -t game-server ./game-server
docker tag game-server:latest $(terraform output -raw game_server_ecr_url):latest
docker push $(terraform output -raw game_server_ecr_url):latest

# Build and push init container
docker build -t game-server-init ./game-server/init-container
docker tag game-server-init:latest $(terraform output -raw game_server_init_ecr_url):latest
docker push $(terraform output -raw game_server_init_ecr_url):latest

Step 4: Verify GameLift Fleet

# Check fleet status
aws gamelift describe-container-fleet \
  --fleet-id $(terraform output -raw gamelift_fleet_id) \
  --region eu-west-2

# List fleet instances
aws gamelift describe-instances \
  --fleet-id $(terraform output -raw gamelift_fleet_id) \
  --region eu-west-2

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📦 Phase Breakdown

Phase 1: Terraform Infrastructure

Modular infrastructure with 5 reusable modules. Each environment (dev/prod) composes the same modules with different variables.

Key design decisions:

• GameLift Container Fleets — managed game server hosting, no cluster ops overhead
• On-Demand instances — predictable performance, no Spot interruptions during game sessions
• Single NAT Gateway — saves ~$32/month vs one per AZ
• On-demand DynamoDB — PAY_PER_REQUEST billing eliminates capacity planning

Phase 2: Game Server Application

A Node.js demo server exercising the full AWS stack:

• UDP 7777 — Simulated real-time game traffic
• TCP 7778 — Player connection lifecycle (connect → load state → play → save state → disconnect)
• HTTP 8080 — Health checks + Prometheus-ready metrics endpoint

Phase 3: GameLift Container Definitions

Container group definitions (replaces Kubernetes manifests):

• Init container syncs game assets from S3 before the game starts
• Game server container with health checks and environment configuration
• Dev fleet: 1 instance, c5.large, no session protection
• Prod fleet: 2-10 instances, c5.xlarge, auto-scaling, full session protection

Phase 4: CI/CD Pipeline

• CI (on PR): Terraform lint/validate/plan, Docker build, GameLift JSON validation
• CD (on merge): Build → Push to ECR → Update Container Group Definition → Update Fleet

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💰 Cost Estimation

Resource	Estimated Monthly Cost	Notes
GameLift (1x c5.large On-Demand)	~$62	Includes GameLift management fee
NAT Gateway	~$32 + data	Single NAT for cost optimization
DynamoDB	~$0-5	On-demand, pay per request
S3	~$1-5	Depends on asset size
ECR	~$1-3	$0.10/GB/month
NLB	~$16 + data	Per AZ-hour + LCU
Total (Dev)	~$115-125/month

Tip: Destroy dev environments when not in use: terraform destroy -var-file=terraform.tfvars

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🧹 Cleanup

cd terraform/environments/dev
terraform destroy -var-file=terraform.tfvars

# (Optional) Remove the state backend
aws s3 rb s3://game-server-terraform-state --force
aws dynamodb delete-table --table-name terraform-state-lock

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🔐 GitHub Actions Secrets

Secret	Description
AWS_ACCESS_KEY_ID	IAM user access key (or use OIDC federation)
AWS_SECRET_ACCESS_KEY	IAM user secret key
AWS_ACCOUNT_ID	Your 12-digit AWS account ID

Recommended: Replace static credentials with GitHub OIDC Federation for production use.

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🔮 Future Improvements

• GameLift FlexMatch — Automatic player matchmaking
• Monitoring — CloudWatch dashboards + Prometheus/Grafana
• CloudFront CDN — Cache and deliver game assets globally
• AWS WAF — DDoS protection for game traffic
• Multi-region fleets — Deploy across regions for low-latency global access
• GameLift Queues — Multi-fleet placement for optimal latency

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🛠️ Technologies Used

Category	Technology
Cloud Provider	AWS (VPC, GameLift, ECR, S3, DynamoDB, NLB)
Infrastructure as Code	Terraform ~> 5.0
Game Server Hosting	Amazon GameLift Container Fleets (On-Demand)
Container Runtime	Docker (multi-stage builds)
CI/CD	GitHub Actions
Application	Node.js 20 + AWS SDK v3
State Management	DynamoDB (on-demand)
Asset Storage	S3 (versioned, encrypted)
Region	eu-west-2 (London)

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📄 License

This project is licensed under the MIT License.