Rule

The Rule resource allows you to manage AWS Events Rules that enable you to respond to events across AWS services. You can set up rules to trigger actions based on events, schedules, or specific patterns.

Minimal Example

Create a basic events rule that triggers on a schedule.

import AWS from "alchemy/aws/control";

const dailyRule = await AWS.Events.Rule("dailyRule", {
  name: "DailyEventTrigger",
  scheduleExpression: "rate(1 day)",
  description: "This rule triggers once a day."
});

Advanced Configuration

Configure an events rule with an event pattern and multiple targets.

const patternRule = await AWS.Events.Rule("patternRule", {
  name: "PatternMatchEventTrigger",
  eventPattern: {
    source: ["aws.ec2"],
    detailType: ["AWS API Call via CloudTrail"],
    detail: {
      eventSource: ["ec2.amazonaws.com"],
      eventName: ["RunInstances"]
    }
  },
  targets: [{
    id: "invokeLambda",
    arn: "arn:aws:lambda:us-east-1:123456789012:function:myFunction"
  }],
  description: "Triggers on EC2 instance creation events."
});

Schedule-Based Rule

Create a rule that runs based on a cron schedule.

const cronRule = await AWS.Events.Rule("cronRule", {
  name: "WeeklyReportTrigger",
  scheduleExpression: "cron(0 12 ? * MON *)", // Every Monday at 12:00 PM UTC
  description: "Triggers every week for generating reports.",
  targets: [{
    id: "generateReportFunction",
    arn: "arn:aws:lambda:us-east-1:123456789012:function:generateReport"
  }]
});

Event Bus Integration

Create a rule that listens to a specific event bus.

const eventBusRule = await AWS.Events.Rule("eventBusRule", {
  name: "CustomEventBusRule",
  eventBusName: "my-custom-bus",
  eventPattern: {
    source: ["my.application"],
    detailType: ["applicationUpdate"]
  },
  targets: [{
    id: "notifySns",
    arn: "arn:aws:sns:us-east-1:123456789012:myTopic"
  }],
  description: "Triggers notifications on application updates."
});

Enabling and Disabling Rules

Create a rule and set its initial state.

const stateRule = await AWS.Events.Rule("stateRule", {
  name: "StateControlRule",
  scheduleExpression: "rate(1 hour)",
  state: "ENABLED", // Can be "ENABLED" or "DISABLED"
  description: "This rule is enabled and triggers every hour."
});