운영 우수성 및 보안 원칙

# Six Pillars of the Well-Architected Framework:
# 1. Operational Excellence
# 2. Security
# 3. Reliability
# 4. Performance Efficiency
# 5. Cost Optimisation
# 6. Sustainability

# Each pillar has:
# - Design principles (practices to adopt)
# - Questions (evaluation criteria)
# - Best practices (specific implementation guidance)

# CloudFormation: operations as code
aws cloudformation create-stack \
  --stack-name my-app-stack \
  --template-url s3://my-bucket/template.yaml \
  --parameters ParameterKey=Env,ParameterValue=prod

# Rollback on failure is automatic
# Small, reversible change: deploy a new AMI
aws autoscaling start-instance-refresh \
  --auto-scaling-group-name my-asg \
  --preferences MinHealthyPercentage=90

# CloudFormation change set: preview before applying
aws cloudformation create-change-set \
  --stack-name my-app-stack \
  --change-set-name update-instance-type \
  --template-url s3://my-bucket/updated-template.yaml

# Review the change set
aws cloudformation describe-change-set \
  --stack-name my-app-stack \
  --change-set-name update-instance-type

# Execute after review
aws cloudformation execute-change-set \
  --change-set-name update-instance-type \
  --stack-name my-app-stack

# Enable X-Ray tracing on Lambda
aws lambda update-function-configuration \
  --function-name my-function \
  --tracing-config Mode=Active

# X-Ray service map shows:
# - Which services are called
# - Response time percentiles
# - Error rates
# - Downstream dependencies
# Helps identify bottlenecks and failure points

# Systems Manager Automation: execute runbook
aws ssm start-automation-execution \
  --document-name 'AWS-RestartEC2Instance' \
  --parameters InstanceId=i-1234567890abcdef0

# Custom automation document for patching runbook
aws ssm create-document \
  --name 'PatchAndRestart' \
  --document-type Automation \
  --content file://patch-runbook.json

# Security at all layers (defence in depth):
# Edge:         AWS WAF + Shield
# Network:      VPC, Security Groups, NACLs
# Compute:      Security Groups, SSM Patch Manager
# Application:  API Gateway authorizers, Cognito
# Data:         KMS encryption, S3 bucket policies
# Identity:     IAM least-privilege, MFA, roles
# Audit:        CloudTrail, AWS Config, Security Hub

# IAM Access Analyzer to find overly permissive policies
aws accessanalyzer create-analyzer \
  --analyzer-name my-analyzer \
  --type ACCOUNT

# List findings (e.g., S3 bucket accessible externally)
aws accessanalyzer list-findings \
  --analyzer-arn arn:aws:access-analyzer:us-east-1:123:analyzer/my-analyzer

# Check unused permissions
aws iam generate-service-last-accessed-details \
  --arn arn:aws:iam::123:role/MyRole

# Enforce HTTPS-only on S3 bucket
aws s3api put-bucket-policy \
  --bucket my-sensitive-bucket \
  --policy '{
    "Statement": [{
      "Effect": "Deny",
      "Principal": "*",
      "Action": "s3:*",
      "Resource": "arn:aws:s3:::my-sensitive-bucket/*",
      "Condition": {
        "Bool": {"aws:SecureTransport": "false"}
      }
    }]
  }'

# EventBridge rule for GuardDuty finding
aws events put-rule \
  --name isolate-compromised-instance \
  --event-pattern '{
    "source": ["aws.guardduty"],
    "detail-type": ["GuardDuty Finding"],
    "detail": {
      "severity": [{"numeric": [">", 7]}],
      "type": [{"prefix": "UnauthorizedAccess"}]
    }
  }'

# Lambda target automatically:
# 1. Terminates instance from ASG
# 2. Creates forensic snapshot of EBS volume
# 3. Notifies security team via SNS

# Query CloudTrail to find who deleted an S3 bucket
aws cloudtrail lookup-events \
  --lookup-attributes AttributeKey=EventName,AttributeValue=DeleteBucket \
  --start-time 2026-06-01T00:00:00Z \
  --end-time 2026-06-21T23:59:59Z

# AWS Config rule: S3 must not be publicly accessible
aws configservice put-config-rule \
  --config-rule '{
    "ConfigRuleName": "s3-bucket-public-read-prohibited",
    "Source": {"Owner":"AWS","SourceIdentifier":"S3_BUCKET_PUBLIC_READ_PROHIBITED"}
  }'

# Enable Security Hub
aws securityhub enable-security-hub \
  --enable-default-standards

# Enable specific standards
aws securityhub batch-enable-standards \
  --standards-subscription-requests \
    StandardsArn=arn:aws:securityhub:::ruleset/cis-aws-foundations-benchmark/v/1.2.0 \
    StandardsArn=arn:aws:securityhub:us-east-1::standards/pci-dss/v/3.2.1