@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/