aws-cost-optimizer

Analyze AWS spending patterns, identify waste, and provide actionable cost reduction strategies.

## When to Use This Skill

Use this skill when you need to analyze AWS spending, identify cost optimization opportunities, or reduce cloud waste.

## Core Capabilities

**Cost Analysis**
- Parse AWS Cost Explorer data for trends and anomalies
- Break down costs by service, region, and resource tags
- Identify month-over-month spending increases

**Resource Optimization**
- Detect idle EC2 instances (low CPU utilization)
- Find unattached EBS volumes and old snapshots
- Identify unused Elastic IPs
- Locate underutilized RDS instances
- Find old S3 objects eligible for lifecycle policies

**Savings Recommendations**
- Suggest Reserved Instance/Savings Plans opportunities
- Recommend instance rightsizing based on CloudWatch metrics
- Identify resources in expensive regions
- Calculate potential savings with specific actions

## AWS CLI Commands

### Get Cost and Usage
```bash
# Last 30 days cost by service
aws ce get-cost-and-usage \
  --time-period Start=$(date -d '30 days ago' +%Y-%m-%d),End=$(date +%Y-%m-%d) \
  --granularity MONTHLY \
  --metrics BlendedCost \
  --group-by Type=DIMENSION,Key=SERVICE

# Daily costs for current month
aws ce get-cost-and-usage \
  --time-period Start=$(date +%Y-%m-01),End=$(date +%Y-%m-%d) \
  --granularity DAILY \
  --metrics UnblendedCost
```

### Find Unused Resources
```bash
# Unattached EBS volumes
aws ec2 describe-volumes \
  --filters Name=status,Values=available \
  --query 'Volumes[*].[VolumeId,Size,VolumeType,CreateTime]' \
  --output table

# Unused Elastic IPs
aws ec2 describe-addresses \
  --query 'Addresses[?AssociationId==null].[PublicIp,AllocationId]' \
  --output table

# Idle EC2 instances (requires CloudWatch)
aws cloudwatch get-metric-statistics \
  --namespace AWS/EC2 \
  --metric-name CPUUtilization \
  --dimensions Name=InstanceId,Value=i-xxxxx \
  --start-time $(date -u -d '7 days ago' +%Y-%m-%dT%H:%M:%S) \
  --end-time $(date -u +%Y-%m-%dT%H:%M:%S) \
  --period 86400 \
  --statistics Average

# Old EBS snapshots (>90 days)
aws ec2 describe-snapshots \
  --owner-ids self \
  --query 'Snapshots[?StartTime<=`'$(date -d '90 days ago' --iso-8601)'`].[SnapshotId,StartTime,VolumeSize]' \
  --output table
```

### Rightsizing Analysis
```bash
# List EC2 instances with their types
aws ec2 describe-instances \
  --query 'Reservations[*].Instances[*].[InstanceId,InstanceType,State.Name,Tags[?Key==`Name`].Value|[0]]' \
  --output table

# Get RDS instance utilization
aws cloudwatch get-metric-statistics \
  --namespace AWS/RDS \
  --metric-name CPUUtilization \
  --dimensions Name=DBInstanceIdentifier,Value=mydb \
  --start-time $(date -u -d '30 days ago' +%Y-%m-%dT%H:%M:%S) \
  --end-time $(date -u +%Y-%m-%dT%H:%M:%S) \
  --period 86400 \
  --statistics Average,Maximum
```

## Optimization Workflow

1. **Baseline Assessment**
   - Pull 3-6 months of cost data
   - Identify top 5 spending services
   - Calculate growth rate

2. **Quick Wins**
   - Delete unattached EBS volumes
   - Release unused Elastic IPs
   - Stop/terminate idle EC2 instances
   - Delete old snapshots

3. **Strategic Optimization**
   - Analyze Reserved Instance coverage
   - Review instance types vs. workload
   - Implement S3 lifecycle policies
   - Consider Spot instances for non-critical workloads

4. **Ongoing Monitoring**
   - Set up AWS Budgets with alerts
   - Enable Cost Anomaly Detection
   - Tag resources for cost allocation
   - Monthly cost review meetings

## Cost Optimization Checklist

- [ ] Enable AWS Cost Explorer
- [ ] Set up cost allocation tags
- [ ] Create AWS Budget with alerts
- [ ] Review and delete unused resources
- [ ] Analyze Reserved Instance opportunities
- [ ] Implement S3 Intelligent-Tiering
- [ ] Review data transfer costs
- [ ] Optimize Lambda memory allocation
- [ ] Use CloudWatch Logs retention policies
- [ ] Consider multi-region cost differences

## Example Prompts

**Analysis**
- "Show me AWS costs for the last 3 months broken down by service"
- "What are my top 10 most expensive resources?"
- "Compare this month's spending to last month"

**Optimization**
- "Find all unattached EBS volumes and calculate savings"
- "Identify EC2 instances with <5% CPU utilization"
- "Suggest Reserved Instance purchases based on usage"
- "Calculate savings from deleting snapshots older than 90 days"

**Implementation**
- "Create a script to delete unattached volumes"
- "Set up a budget alert for $1000/month"
- "Generate a cost optimization report for leadership"

## Best Practices

- Always test in non-production first
- Verify resources are truly unused before deletion
- Document all cost optimization actions
- Calculate ROI for optimization efforts
- Automate recurring optimization tasks
- Use AWS Trusted Advisor recommendations
- Enable AWS Cost Anomaly Detection

## Integration with Kiro CLI

This skill works seamlessly with Kiro CLI's AWS integration:

```bash
# Use Kiro to analyze costs
kiro-cli chat "Use aws-cost-optimizer to analyze my spending"

# Generate optimization report
kiro-cli chat "Create a cost optimization plan using aws-cost-optimizer"
```

## Safety Notes

- **Risk Level: Low** - Read-only analysis is safe
- **Deletion Actions: Medium Risk** - Always verify before deleting resources
- **Production Changes: High Risk** - Test rightsizing in dev/staging first
- Maintain backups before any deletion
- Use `--dry-run` flag when available

## Additional Resources

- [AWS Cost Optimization Best Practices](https://aws.amazon.com/pricing/cost-optimization/)
- [AWS Well-Architected Framework - Cost Optimization](https://docs.aws.amazon.com/wellarchitected/latest/cost-optimization-pillar/welcome.html)
- [AWS Cost Explorer API](https://docs.aws.amazon.com/cost-management/latest/APIReference/Welcome.html)