VT-lambdas

Lambda description

• Lambda for File Access Patterns

  • lambda_for_fileDelete This lambda takes the userId and fileId and deletes the corresponding file, update the storage_used for the user with the given userId and delete all the corresponding URLs for the deleted file.
  • lambda_for_fileDetails This lambda takes the userId and fileId and returns the file details corresponding to the given fileId.
  • lambda_for_fileList This lambda returns the file uploaded by a specific user. It supports pagination, text-based search and time-series query.
  • lambda_for_fileUpload This lambda takes the userId and file object and inserts the file object into Dynamodb.

• Lambda for URL Access patterns

  • lambda_for_deleteURL This lambda takes the fileId and urlId and deletes the URL corresponding to the given urlId.
  • lambda_for_generateURL This lambda takes fileId and URL object and generate a new URL corresponding to the given fileId.
  • lambda_for_updateURL This lambda takes the fileld, urlId and URL object and update the URL corresponding to the given urlId.
  • lambda_for_urlList This lambda takes the fileId and return list of URLs corresponding to the given the fileId.

• Lambda for User Access patterns

  • lambda_for_getUser This lambda takes the userId and return the user record corresponding to the given userId.
  • lambda_for_createUser This lambda accepts the parameters from AWS Cognito and create a record for the user in the DynamoDb

How to use setup.py for managing lambdas

• Each lambda reside in a separate folder which is a node project hence we are using python script to create, build and list the lambdas.

• Location: lambdas/setup.py

• Requirements

  • Terminal/Command promt
  • Python 3.x
  • python added as a path variable. To check run command python --version

• Run python setupy.py

• Available options

  • --help or -h: returns the docstring describing the available options and their arguments.
  • --init or -i: creates new lambda by taking various input form user.
  • --build or -b:
    • build and generate the artifact as [lambda-name].zip in ../out directory.
    • Pass . as argument to build all the lambdas or specific path to build a single lambda.
    • Example python setup.py -b . or python setup.py -b user_access_patterns/lambda_for_createUser
  • --ls or -ls: lists all the lambdas available/created.

  Testing the lambdas locally

  • Set up dynamo db using the CreateTable.js file.
  • For setting up dynamodb on aws, create keys.json file in the location mentioned. The content of keys.json file are shown below. Set up your aws IAM role accessKeyId and secretAccessKey in the file. Change the region to ap-south-1

  { "accessKeyId": "<YOUR_ACCESS_KEY_ID>",
  "secretAccessKey": "<YOUR_SECRET_ACCESS_KEY>",
  "region": "<REGION>" }

• For setting dynamodb locally, comment out the local setup code as mentioned in CreateTable.js file
• All the lambdas can be tested locally using serverless or aws SAM or docker.

Using docker images: Testing the lambda locally using docker requires a docker image file. If you are new to docker, refer the official documentation.

• Creating Dockerfile aws documentation.
• Testing lambda using Dockerfile documentation.

Using aws SAM: SAM (Serverless Application Model) is an aws service which provides interface for testing and debugging.

• Getting started with SAM
• Refer local function invokation documentation for SAM.

Using serverless: Serverless is an open source project that allows creation, deployment and testing of serverless applications.

• Installing and setting up serverless
• Copy the lambda to be tested in the serverless project directory.
• use serverless invoke local command to test your lambdas locally. Refer the documentation

Swagger API documentation

https://app.swaggerhub.com/apis-docs/code-gambit/V-Transfer/1.0.0