Serverless Local Schedule

Schedule AWS CloudWatch Event based invocations in local time(with DST support!)

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Serverless Local Schedule

serverless npm

This plugin allows you to specify a timezone on your lambdas triggered by AWS CloudWatch Events.


Originally developed by Capital One, now maintained in scope of Serverless, Inc

Capital One considers itself the bank a technology company would build. It's delivering best-in-class innovation so that its millions of customers can manage their finances with ease. Capital One is all-in on the cloud and is a leader in the adoption of open source, RESTful APIs, microservices and containers. We build our own products and release them with a speed and agility that allows us to get new customer experiences to market quickly. Our engineers use artificial intelligence and machine learning to transform real-time data, software and algorithms into the future of finance, reimagined.


Install

sls plugin install -n serverless-local-schedule

For example:

functions:
  hello:
    handler: handler.hello
    events:
      - schedule:
          rate: cron(0 10 * * ? *)
          timezone: America/New_York

It works by converting that into 6 different schedules, effectively the same as having the following configuration:

functions:
  hello:
    handler: handler.hello
    events:
      - schedule:
          rate: cron(0 15 * 1-2,12 ? *) # full non-DST months
      - schedule:
          rate: cron(0 15 1-10 3 ? *) # non-DST portion of March
      - schedule:
          rate: cron(0 14 11-31 3 ? *) # DST portion of March
      - schedule:
          rate: cron(0 14 * 4-10 ? *) # full DST months
      - schedule:
          rate: cron(0 14 1-3 11 ? *) # DST portion of November
      - schedule:
          rate: cron(0 15 4-31 11 ? *) # non-DST portion of November

NOTE: The - schedule: cron(* * * * ? *) short syntax isn't supported.

NOTE: Unfortunately you cannot specify day of the week in the cron expression i.e. cron(0 7 ? * MON-FRI *). This is because to support the split months (March & November in the US), the plugin has to specify a day of month (EG: November 1-3 in 2018), so you cannot specify a DOW other than ? unfortunately. Recommended workaround for this is to move the day of week check into your code so it's just a no-op on non weekdays for instance.