varun-jalandery / dynaint

A service based on Lambdas and DynamoDB

Aws - Lambdas, Api Gateway and DynamoDB - PR 1 2

This project is done in node js. For unit and functional tests mocha and chai libraries are used.

Unit tests and functional tests automatically run when code is committed. If tests fail, code is not committed.

Also linting runs automatically, when code is committed, if linting fails, code is not committed.

For computing test coverage istanbul library is used.

For making requests to aws api gateways in functional tests, aws4 module is used for signing the request for authentication

For rate limiting, aws api gateway is configured. 60 requests per second is configured.

For storing the data, Amazon DynamoDb is used. Partition key is used as mobile.

Next Steps:

1. Add Global Secondary Index in DynamoDb to support getting the documents via email. This will enable the feature of updating the user both via email or mobile.

Future Steps:

1. Add console task to upload Lambdas to Aws cloud. This will speed up the process of deploying lambdas. Also it would make this step less error prone, because manually uploading lambdas can include mistakes.

Project Directory/File Structure

1. src - This directory contains the source code.
2. test - This directory contains the unit and functional tests.
3. .env.sample - This is the sample file for the environment vars. It needs to be copied into the file names .env. Then fill in the correct values of the environment vars.
4. .eslintrc.json - coding styles are configured in this file
5. src/lambdas - Aws Lambdas are defined this directory.
6. src/lambdas/UpsertUser.js - Aws lambda for creating the user. This lambdas is available to the users via Aws Api Gateway. This lambda connects to DyanmoDB and writes the data to it.
7. src/lambdas/UpsertUserInterests.js - Aws lambda for adding interests to the existing user. This lambdas is also exposed via Aws Api Gateway and connects to Dynamo db to write the user interests.
8. src/lib/DynamoDbQuery - This class is responsible for creating the DynamoDB Query for upserts. This class is also used by the lambdas in the aws cloud.
9. src/lib/LambdaFy.js - This class is responsible for formatting the response from the lambdas back to Api Gateway and hence to end user. This class is also used by lambdas in the aws cloud.
10. AwsSign - This class is responsible for creating the signature for requests to api gateway. This class is not used by lambdas in the aws cloud. Instead this class is used by functional tests to call api gateway.
11. src/test/unit - This directory contains the unit tests
12. src/test/functional - This directory contains the functional tests.
13. src/test/functional/apis - This directory contains the functional tests for http apis.
14. src/test/functional/lambdas - This directory contains the functional tests for lambdas. These tests directly call aws lambdas without the api gateway.
15. src/lib/Lambda - This class has invoke method to directly call aws lambdas.

Commands

To install the dependencies

$ npm install

To run the tests

$ npm test

To check code for linting

$ npm run lint

To fix linting

$ npm run lint:fix

To compute coverage

$ npm run test:coverage

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