aws-infrastructure

AWS Infrastructure Expert

When to Use

• EC2 instance setup and configuration
• VPC and networking setup
• Security group configuration
• Application Load Balancer setup
• Route53 DNS configuration
• SSL/TLS certificate management (ACM)
• Auto-scaling groups
• CloudWatch monitoring

EC2 Setup

Instance Types

• Development: t3.medium (2 vCPU, 4GB RAM)
• Production (small): t3.large (2 vCPU, 8GB RAM)
• Production (medium): m5.large (2 vCPU, 8GB RAM)

Storage

• Use gp3 SSD volumes
• Development: 20GB minimum
• Production: 100GB+ based on needs
• Enable EBS snapshots for backups

Key Pairs

• Generate or import SSH key pairs
• Store private keys securely
• Use IAM roles instead of access keys when possible

VPC Configuration

Basic Setup

• Create VPC with CIDR block (e.g., 10.0.0.0/16)
• Create public and private subnets
• Set up Internet Gateway
• Configure route tables
• Set up NAT Gateway for private subnets (if needed)

Subnets

• Public subnets: For load balancers, bastion hosts
• Private subnets: For application servers, databases
• Multi-AZ for high availability

Security Groups

Application Security Group

Inbound:
- HTTP (80) from ALB security group
- HTTPS (443) from ALB security group
- SSH (22) from bastion/your IP only

Outbound:
- All traffic (0.0.0.0/0)

Database Security Group

Inbound:
- Postgres (5432) from application security group only
- Redis (6379) from application security group only
- SSH (22) from bastion/your IP only

Outbound:
- All traffic (0.0.0.0/0)

Load Balancer Security Group

Inbound:
- HTTP (80) from 0.0.0.0/0
- HTTPS (443) from 0.0.0.0/0

Outbound:
- HTTP (80) to application security group
- HTTPS (443) to application security group

Application Load Balancer

Setup

1. Create ALB in public subnets
2. Configure target groups (EC2 instances)
3. Set up health checks
4. Configure listeners (HTTP → HTTPS redirect)
5. Attach SSL certificate from ACM

Health Checks

• Path: /health or /api/health
• Protocol: HTTP
• Port: 3001 (backend) or 3000 (frontend)
• Healthy threshold: 2
• Unhealthy threshold: 2
• Timeout: 5 seconds
• Interval: 30 seconds

Route53 DNS

Domain Setup

1. Create hosted zone for domain
2. Create A record (alias) pointing to ALB
3. Create CNAME for www subdomain
4. Update nameservers at domain registrar

SSL/TLS (ACM)

1. Request certificate in ACM (us-east-1 for CloudFront/ALB)
2. Validate via DNS (add CNAME records)
3. Attach certificate to ALB listener
4. Certificate auto-renews

CloudWatch Monitoring

Metrics

• EC2: CPU, Memory, Disk, Network
• ALB: Request count, Target response time, HTTP errors
• Custom metrics for application-specific data

Alarms

• High CPU utilization
• Low disk space
• Application errors (via CloudWatch Logs)
• Unhealthy target instances

Best Practices

• Use IAM roles instead of access keys
• Enable CloudTrail for audit logging
• Use VPC endpoints for AWS service access
• Implement least privilege security groups
• Use private subnets for databases
• Enable encryption at rest for EBS volumes
• Set up automated backups (EBS snapshots)
• Monitor costs with AWS Cost Explorer

Integration

This skill integrates with postgres-ops for Postgres setup (RDS or EC2) and /deploy for deployment workflows.