@1mill/journal

Idempotently invoke AWS Lambda functions with Cloudevents.

Getting started

npm install @1mill/journal

// * index.js
import { Locker, withIdempotency } from '@1mill/journal'

const locker = new Locker({
  name:  'my-locker-db-name',
  table: 'my-collection-name',
  uri:   'mongodb://...:27017/',
})

const func = (cloudevent, ctx) => {
  console.log('Running once: ', cloudevent)
  return { cloudevent }
}

export const handler = async (cloudevent, ctx) => withIdempotency(cloudevent, ctx, { func, locker })

Locker

Name	Required	Types	Default	Environment	Description
expireAfterSeconds		number	86400 (1 day)	MILL_JOURNAL_EXPIRE_AFTER_SECONDS	How long a Cloudevent idempotency key will keep-alive
name	yes	string		MILL_JOURNAL_NAME	The name of the database itself
options		object	{}		Options pass to the database client
table	yes	string		MILL_JOURNAL_TABLE	The name of the table inside the database
uri	yes	string		MILL_JOURNAL_URI	URI to connect to database

withIdempotency

Name	Required	Types	Default	Environment	Description
func	yes	function			The function containing business logic that will run
locker	yes	Locker			The Locker in which idempotency keys will be checked against

References

• https://developer.ibm.com/tutorials/reactive-in-practice-5/
• https://docs.powertools.aws.dev/lambda/python/latest/utilities/idempotency/#idempotency-request-flow
• https://multithreaded.stitchfix.com/blog/2017/06/26/patterns-of-soa-idempotency-key/