Cost Explorer、Budgets、コスト配分タグ

コストを可視化する必要性

# AWS cost management tools:
# Cost Explorer:        analyse past spending, forecast
# AWS Budgets:          alert when approaching/exceeding limits
# Cost Allocation Tags: attribute costs to teams/projects
# Cost and Usage Report (CUR): granular data to S3 for BI tools
# Billing Dashboard:    high-level current month summary
# Savings Plans/RI:     analyse commitment coverage

Cost Explorer：支出の分析

# Cost Explorer API: get last 30 days spend by service
aws ce get-cost-and-usage \
  --time-period Start=2026-05-21,End=2026-06-21 \
  --granularity MONTHLY \
  --metrics BlendedCost \
  --group-by Type=DIMENSION,Key=SERVICE \
  --query 'ResultsByTime[0].Groups[].{Service:Keys[0],Cost:Metrics.BlendedCost.Amount}' \
  --output table

# Example output:
# Amazon EC2:     $8,450
# Amazon RDS:     $2,200
# Amazon S3:      $430
# AWS Lambda:     $85

コスト異常検出

# Create Cost Anomaly Detection monitor
aws ce create-anomaly-monitor \
  --anomaly-monitor '{
    "MonitorName": "AllServicesMonitor",
    "MonitorType": "DIMENSIONAL",
    "MonitorDimension": "SERVICE"
  }'

# Create alert subscription for anomalies > $100
aws ce create-anomaly-subscription \
  --anomaly-subscription '{
    "SubscriptionName": "daily-anomaly-alert",
    "MonitorArnList": ["arn:aws:ce::123:anomalymonitor/xxx"],
    "Subscribers": [{"Address":"finops@example.com","Type":"EMAIL"}],
    "Threshold": 100,
    "Frequency": "DAILY"
  }'

AWS Budgets：積極的なコストアラート

# Create monthly cost budget with alerts
aws budgets create-budget \
  --account-id 123456789012 \
  --budget '{
    "BudgetName": "monthly-production-budget",
    "BudgetLimit": {"Amount": "10000", "Unit": "USD"},
    "TimeUnit": "MONTHLY",
    "BudgetType": "COST"
  }' \
  --notifications-with-subscribers '[{
    "Notification": {
      "NotificationType": "ACTUAL",
      "ComparisonOperator": "GREATER_THAN",
      "Threshold": 80,
      "ThresholdType": "PERCENTAGE"
    },
    "Subscribers": [{"SubscriptionType":"EMAIL","Address":"cto@example.com"}]
  }]'

自動対応のためのBudget Actions

# Budget Action: stop EC2 instances when budget exceeded
aws budgets create-budget-action \
  --account-id 123456789012 \
  --budget-name monthly-dev-budget \
  --notification-type ACTUAL \
  --action-type STOP_EC2_INSTANCES \
  --action-threshold '{
    "ActionThresholdValue": 100,
    "ActionThresholdType": "PERCENTAGE"
  }' \
  --definition '{
    "SsmActionDefinition": {
      "ActionSubType": "STOP_EC2_INSTANCES",
      "Region": "us-east-1",
      "InstanceIds": ["i-dev-1","i-dev-2"]
    }
  }' \
  --execution-role-arn arn:aws:iam::123:role/BudgetActionsRole \
  --approval-model AUTOMATIC

コスト配分タグ

# Tag an EC2 instance with cost allocation tags
aws ec2 create-tags \
  --resources i-1234567890abcdef0 \
  --tags \
    Key=Project,Value=OrderService \
    Key=Environment,Value=Production \
    Key=Team,Value=PlatformEng \
    Key=CostCenter,Value=CC-1042

# Activate tag in Billing console (CLI)
aws ce create-cost-category-definition \
  --name ProjectCosts \
  --rules '[{"Value":"OrderService","Rule":{"Tags":{"Key":"Project","Values":["OrderService"]}}}]'

Tag Policiesによるタグの適用

# Create Tag Policy in AWS Organizations
aws organizations create-policy \
  --name RequiredTagsPolicy \
  --type TAG_POLICY \
  --content '{
    "tags": {
      "Environment": {
        "tag_key": {"@@assign": "Environment"},
        "tag_value": {"@@assign": ["Production","Staging","Development"]}
      },
      "Project": {
        "tag_key": {"@@assign": "Project"}
      }
    }
  }'

# Attach to an OU
aws organizations attach-policy \
  --policy-id p-12345 \
  --target-id ou-root-abc123

Cost and Usage Report（CUR）

# Create CUR definition (deliver to S3)
aws cur put-report-definition \
  --report-definition '{
    "ReportName": "my-cost-report",
    "TimeUnit": "HOURLY",
    "Format": "Parquet",
    "Compression": "Parquet",
    "AdditionalSchemaElements": ["RESOURCES"],
    "S3Bucket": "my-cur-bucket",
    "S3Prefix": "reports",
    "S3Region": "us-east-1",
    "ReportVersioning": "OVERWRITE_REPORT",
    "IncludeResourceIds": true
  }'

# Query with Athena:
# SELECT resource_id, sum(line_item_blended_cost)
# FROM cur_table
# WHERE resource_tags_user_project = 'OrderService'
# GROUP BY resource_id

論理的なグループ化のためのCost Categories

# Create a Cost Category
aws ce create-cost-category-definition \
  --name 'EnvironmentType' \
  --rules '[{
    "Value": "Production",
    "Rule": {"Tags":{"Key":"Environment","Values":["prod","production","PROD"]}}
  },{
    "Value": "Development",
    "Rule": {"Tags":{"Key":"Environment","Values":["dev","development","test"]}}
  }]' \
  --default-value 'Untagged'

# Use in Cost Explorer to filter:
# Filter: CostCategory = Production
# See all production costs regardless of tag variations

FinOpsの実践方法

# FinOps implementation checklist:
# [ ] Activate cost allocation tags in Billing console
# [ ] Enable Cost Anomaly Detection
# [ ] Create monthly budgets per team/account
# [ ] Set up Budget Actions for dev accounts
# [ ] Enable CUR delivery to S3
# [ ] Create Athena tables over CUR for ad-hoc queries
# [ ] Build QuickSight dashboard for leadership
# [ ] Schedule monthly cost review meetings
# [ ] Track month-over-month cost per unit of work

コスト予測と計画

# Get 3-month cost forecast
aws ce get-cost-forecast \
  --time-period Start=2026-07-01,End=2026-09-30 \
  --metric BLENDED_COST \
  --granularity MONTHLY \
  --filter '{
    "Dimensions": {
      "Key": "SERVICE",
      "Values": ["Amazon EC2"]
    }
  }' \
  --query 'ForecastResultsByTime[].{Month:TimePeriod.Start,Forecast:MeanValue,Lower:PredictionIntervalLowerBound,Upper:PredictionIntervalUpperBound}'

理解度チェック

レッスンのまとめ