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Cron

The Cron construct is a higher level CDK construct that makes it easy to create a cron job. You can create a cron job by handler function and specifying the schedule it needs to run on. Internally this construct uses a EventBridge Rule.

Examples​

Rate schedule​

import { Cron } from "sst/constructs";

new Cron(stack, "Cron", {
  schedule: "rate(1 minute)",
  job: "src/lambda.main",
});

Cron schedule​

new Cron(stack, "Cron", {
  schedule: "cron(15 10 * * ? *)",
  job: "src/lambda.main",
});

Permissions​

Allow the function to access S3.

const cron = new Cron(stack, "Cron", {
  schedule: "rate(1 minute)",
  job: "src/lambda.main",
});

cron.attachPermissions(["s3"]);

Disabling​

Disable the cron job from automatically running while developing.

new Cron(stack, "Cron", {
  schedule: "rate(1 minute)",
  job: "src/lambda.main",
  enabled: !app.local,
});

Advanced examples​

Configuring the event rule​

Configure the internally created EventBus Rule.

import { Schedule } from "aws-cdk-lib/aws-events";

new Cron(stack, "Cron", {
  job: "src/lambda.main",
  cdk: {
    rule: {
      schedule: Schedule.cron({ minute: "0", hour: "4" }),
    },
  },
});

Configuring the event target​

Configure the internally created EventBus Target.

import { RuleTargetInput } from "aws-cdk-lib/aws-events";

new Cron(stack, "Cron", {
  schedule: "rate(1 minute)",
  job: {
    function: "src/lambda.main",
    cdk: {
      target: {
        event: RuleTargetInput.fromObject({
          key: "value",
        }),
      },
    },
  },
});

Constructor​

new Cron(scope, id, props)

Parameters

CronProps​

enabled?​

Type : boolean

Default : true

Indicates whether the cron job is enabled.

new Cron(stack, "Cron", {
  job: "src/lambda.main",
  schedule: "rate(5 minutes)",
  enabled: app.mode === "dev",
})

job​

Type : string | Function | CronJobProps

The definition of the function to be executed.

new Cron(stack, "Cron", {
  job : "src/lambda.main",
  schedule: "rate(5 minutes)",
})

schedule?​

Type : rate(${string}) | cron(${string})

The schedule for the cron job.

The string format takes a rate expression.

rate(1 minute)
rate(5 minutes)
rate(1 hour)
rate(5 hours)
rate(1 day)
rate(5 days)

Or as a cron expression.

cron(15 10 * * ? *)    // 10:15 AM (UTC) every day.
new Cron(stack, "Cron", {
  job: "src/lambda.main",
  schedule: "rate(5 minutes)",
});
new Cron(stack, "Cron", {
  job: "src/lambda.main",
  schedule: "cron(15 10 * * ? *)",
});

cdk?​

Type :

cdk.id?​

Type : string

Allows you to override default id for this construct.

cdk.rule?​

Type : RuleProps

Override the default settings this construct uses internally to create the events rule.

Properties​

An instance of Cron has the following properties.

id​

Type : string

jobFunction​

Type : Function

The internally created Function instance that'll be run on schedule.

cdk​

Type :

cdk.rule​

Type : Rule

The internally created CDK EventBridge Rule instance.

Methods​

An instance of Cron has the following methods.

attachPermissions​

attachPermissions(permissions)

Parameters

Attaches the given list of permissions to the cron job. This allows the function to access other AWS resources.

cron.attachPermissions(["s3"]);

bind​

bind(constructs)

Parameters

  • constructs Array<BindingResource>

Binds the given list of resources to the cron job.

cron.bind([STRIPE_KEY, bucket]);

CronJobProps​

function​

Type : string | Function | FunctionProps

The function that will be executed when the job runs.

  new Cron(stack, "Cron", {
    job: {
      function: "src/lambda.main",
    },
  });

cdk?​

Type :

cdk.target?​

Type : LambdaFunctionProps

Override the default settings this construct uses internally to create the events rule.