EventBridge：イベントバスとルール

Amazon EventBridgeとは

イベントバス：デフォルト、カスタム、パートナー

# Create a custom event bus for your application
aws events create-event-bus --name my-app-bus

# Put a custom event onto the bus
aws events put-events --entries '[{
  "Source": "com.myapp.orders",
  "DetailType": "OrderPlaced",
  "Detail": "{\"orderId\": \"ORD-123\", \"total\": 99.99}",
  "EventBusName": "my-app-bus"
}]'

イベントパターンルール

# Create a rule that matches EC2 instance state changes to 'stopped'
aws events put-rule \
  --name ec2-stopped-alert \
  --event-bus-name default \
  --event-pattern '{
    "source": ["aws.ec2"],
    "detail-type": ["EC2 Instance State-change Notification"],
    "detail": {
      "state": ["stopped"]
    }
  }' \
  --state ENABLED

ターゲットの設定

# Add an SNS topic and Lambda function as targets for the rule
aws events put-targets \
  --rule ec2-stopped-alert \
  --event-bus-name default \
  --targets '[{
    "Id": "notify-ops",
    "Arn": "arn:aws:sns:us-east-1:123456789012:ops-alerts"
  }, {
    "Id": "auto-remediate",
    "Arn": "arn:aws:lambda:us-east-1:123456789012:function:RestartEC2"
  }]'

入力変換

# Input transformer: extract orderId and total from detail
# InputPathsMap extracts values by JSON path
{
  'InputPathsMap': {
    'orderId': '$.detail.orderId',
    'total': '$.detail.total'
  },
  'InputTemplate': '{
    "message": "New order <orderId> for $<total>",
    "channel": "ops"
  }'
}

スケジュールルール（Cron/Rate）

# Create a scheduled rule that fires every day at midnight UTC
aws events put-rule \
  --name nightly-cleanup \
  --schedule-expression 'cron(0 0 * * ? *)' \
  --state ENABLED

aws events put-targets \
  --rule nightly-cleanup \
  --targets '[{
    "Id": "cleanup-lambda",
    "Arn": "arn:aws:lambda:us-east-1:123456789012:function:NightlyCleanup"
  }]'

イベントのアーカイブとリプレイ

# Create an event archive for the custom bus
aws events create-archive \
  --archive-name my-app-archive \
  --event-source-arn arn:aws:events:us-east-1:123456789012:event-bus/my-app-bus \
  --retention-days 30

# Replay archived events from a specific time window
aws events start-replay \
  --replay-name replay-missed-orders \
  --event-source-arn arn:aws:events:us-east-1:123456789012:archive/my-app-archive \
  --event-start-time 2024-01-10T00:00:00Z \
  --event-end-time 2024-01-10T06:00:00Z \
  --destination '{"Arn": "arn:aws:events:us-east-1:123456789012:event-bus/my-app-bus"}'

アカウント間およびリージョン間のルーティング

# Allow a source account (111111111111) to send events to this bus
aws events put-permission \
  --event-bus-name my-central-bus \
  --action events:PutEvents \
  --principal 111111111111 \
  --statement-id allow-source-account

EventBridge Pipes

# Create an EventBridge Pipe from SQS to Lambda
aws pipes create-pipe \
  --name sqs-to-processor \
  --source arn:aws:sqs:us-east-1:123456789012:incoming-orders \
  --target arn:aws:lambda:us-east-1:123456789012:function:ProcessOrder \
  --role-arn arn:aws:iam::123456789012:role/PipeRole \
  --source-parameters '{
    "SqsQueueParameters": {"BatchSize": 10}
  }' \
  --filter-criteria '{
    "Filters": [{"Pattern": "{\"body\": {\"orderType\": [\"PRIORITY\"]}}"}]
  }'

EventBridge、SNS、SQSの比較

EventBridge Schema Registry

# Enable schema discovery on a custom event bus
aws schemas create-discoverer \
  --source-arn arn:aws:events:us-east-1:123456789012:event-bus/my-app-bus \
  --description 'Auto-discover schemas from app bus'

# List discovered schemas
aws schemas list-schemas \
  --registry-name discovered-schemas

理解度チェック

レッスンのまとめ