Serverless Plugin Offline DynamoDB Stream

Serverless Plugin for emulating dynamodb stream triggering lambda functions offline

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serverless-plugin-offline-dynamodb-stream

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Serverless framework offline plugin to support dynamodb stream

This plugin pull from dynamodb stream and trigger serverless function if any records detected.

Installation

Install package

$ npm install --save serverless-plugin-offline-dynamodb-stream

Usage

Add following config to serverless.yml file.

plugins:
  - serverless-plugin-offline-dynamodb-stream
  - serverless-plugin-offline-kinesis-stream
custom:
  dynamodbStream:
    host: {LOCAL_DYNAMODB_HOST}
    port: {LOCAL_DYNAMODB_PORT}
    pollForever: boolean
    streams:
      - table: {TABLE_NAME}
        functions:
          - {FUNCTION_NAME}
  kinesisStream:
    host: {LOCAL_KINESIS_HOST}
    port: {LOCAL_KINESIS_PORT}
    intervalMillis: 5000
    streams:
      - streamName: {STREAM_NAME}
        functions:
          - {FUNCTION_NAME}

pollForever

  • pollForever can be set to true to indicate that this plugin should continue to poll for dynamodbstreams events indefinity. If pollForever is not set, or is set to false, the plugin will stop polling for events once the end of the stream is reached (when dynamodbstreams.getRecords => data.NextShardIterator === null), or an error occurs.

  • With pollForever set to true the following events will trigger a restart instead of exiting as would happen with pollForever set to false:

    • The end of a Dynamodb Stream is reached (when dynamodbstreams.getRecords => data.NextShardIterator === null)
    • ExpiredIteratorException is thrown from dynamodbstreams.getRecords.
  • This can be useful in scenarios where you have a lambda function as part of a larger service struture, and the other services depend on the functinality in the lambda.

Ensure your local dynamodb is up and running, or you could also consider using serverless-dynamodb-local plugin before start your serverless offline process.

$ serverless offline start

Development

  • Cloning the repo
$ git clone https://github.com/orchestrated-io/serverless-plugin-offline-dynamodb-stream.git
  • Installing dependencies
$ npm install
  • Running scripts
Action Usage
Linting code npm run lint
Running unit tests npm run jest
Running code coverage npm run coverage
Running lint + tests npm test

Demo

> cd demo
> docker-compose up --build
  • open dynamodb admin in browser.
  • adding new item on items table will result event detail printed out in console.

Author

Emmanuel Kong

License

MIT