Eventbridge Schedule Expressions

A small Typescript package that checks AWS EventBridge Scheduler scheduled expressions are valid at compile time. Cron expressions are incredibly powerful but mistakes can be easily made.

Typescripts type system can be used to give better validation that plain strings enforcing rules such as cron minute values are being between 0-59 while hours between 0-23

Cron Expressions

Rate Expressions

Formats

Expression formats are takes from the AWS Schedule Expressions syntax. Feel free to create an issue if you find anything that breaks these formats.

Installation

npm install --save-dev @hexlabs/eventbridge-schedule-expressions

Usage

Kloudformation-ts

import {scheduleExpression} from '@hexlabs/eventbridge-schedule-expressions';

aws.schedulerSchedule({
    groupName: schedulerGroup.name,
    name: 'sheduler',
    scheduleExpression: scheduleExpression('cron(0 * * * ? *)'),
    target: {arn: lambda.attributes.Arn, roleArn: schedulerRole.attributes.Arn},
    flexibleTimeWindow: {mode: 'OFF'},
  },
);

CDK

import {scheduleExpression} from '@hexlabs/eventbridge-schedule-expressions';

new CfnSchedule(this, 'my-schedule', {
  groupName: schedulerGroup.name,
  scheduleExpression:  scheduleExpression('cron(5,35 * * * ? *)'),
  target: {
    arn: lambdaFunction.functionArn,
    roleArn: schedulerRole.roleArn,
  },
  flexibleTimeWindow: {
    mode: 'OFF',
  },
});

AWS SDK

  import {scheduleExpression} from '@hexlabs/eventbridge-schedule-expressions';

  await eventBridge.putRule({
    Name: 'Rule-Name',
    ScheduleExpression: scheduleExpression('cron(5,35 * * * ? *)')
  }).promise();