/zibo-count-words-lambda

Primary LanguageTypeScript

ZIZO AWS Lambda Word Type Counter

Version License: MIT

API endpoint

https://o4gzkfdy7j.execute-api.us-east-1.amazonaws.com/dev/countWords

Request body example:

{

"text": "Hello, WORLD! This is a test. Cats, dogs, and birds: three types of pets. Running, swimming, JUMPING!"

}

Project description

Overview

This AWS Lambda function retrieves a dictionary from an S3 bucket, processes a given text string, and counts the number of words based on their types: noun, verb, adjective, adverb, preposition, conjunction, pronoun, interjection, and determiner.

AWS Lambda Function

The backend of this project is an AWS Lambda function, designed for effective text analysis and word type counting. Key features include:

Dictionary Retrieval: The function fetches a pre-defined dictionary from an Amazon S3 bucket.

Text Analysis: It analyzes the input text, categorizing each word into its respective type.

Word Type Counting: The function counts the number of occurrences of each word type in the text.

Serverless - AWS Node.js Typescript

This project has been generated using the aws-nodejs-typescript template from the Serverless framework.

For detailed instructions, please refer to the documentation.

Installation/deployment instructions

Depending on your preferred package manager, follow the instructions below to deploy your project.

Requirements: NodeJS lts/fermium (v.14.15.0). If you're using nvm, run nvm use to ensure you're using the same Node version in local and in your lambda's runtime.

Using NPM

  • Run npm i to install the project dependencies
  • Run npx sls deploy to deploy this stack to AWS

Using Yarn

  • Run yarn to install the project dependencies
  • Run yarn sls deploy to deploy this stack to AWS

Test your service

This template contains a single lambda function triggered by an HTTP request made on the provisioned API Gateway REST API /countWords route with POST method. The request body must be provided as application/json. The body structure is tested by API Gateway against src/functions/countWords/schema.ts JSON-Schema definition: it must contain the name property.

  • requesting any other path than /countWords with any other method than POST will result in API Gateway returning a 403 HTTP error code
  • sending a POST request to /countWords with a payload not containing a string property named name will result in API Gateway returning a 400 HTTP error code
  • sending a POST request to /countWords with a payload containing a string property named name will result in API Gateway returning a 200 HTTP status code with a message saluting the provided name and the detailed event processed by the lambda

⚠️ As is, this template, once deployed, opens a public endpoint within your AWS account resources. Anybody with the URL can actively execute the API Gateway endpoint and the corresponding lambda. You should protect this endpoint with the authentication method of your choice.

Locally

In order to test the countWords function locally, run the following command:

  • npx sls invoke local -f countWords --path src/functions/countWords/mock.json if you're using NPM
  • yarn sls invoke local -f countWords --path src/functions/countWords/mock.json if you're using Yarn

Check the sls invoke local command documentation for more information.

Remotely

Copy and replace your url - found in Serverless deploy command output - and name parameter in the following curl command in your terminal or in Postman to test your newly deployed application.

curl --location --request POST 'https://myApiEndpoint/dev/countWords' \
--header 'Content-Type: application/json' \
--data-raw '{
    "name": "Frederic"
}'

Template features

Project structure

The project code base is mainly located within the src folder. This folder is divided in:

  • functions - containing code base and configuration for your lambda functions
  • libs - containing shared code base between your lambdas
.
├── src
│   ├── functions               # Lambda configuration and source code folder
│   │   ├── countWords
│   │   │   ├── handler.ts      # `Hello` lambda source code
│   │   │   ├── index.ts        # `Hello` lambda Serverless configuration
│   │   │   ├── mock.json       # `Hello` lambda input parameter, if any, for local invocation
│   │   │   └── schema.ts       # `Hello` lambda input event JSON-Schema
│   │   │
│   │   └── index.ts            # Import/export of all lambda configurations
│   │
│   └── libs                    # Lambda shared code
│       └── apiGateway.ts       # API Gateway specific helpers
│       └── handlerResolver.ts  # Sharable library for resolving lambda handlers
│       └── lambda.ts           # Lambda middleware
│
├── package.json
├── serverless.ts               # Serverless service file
├── tsconfig.json               # Typescript compiler configuration
├── tsconfig.paths.json         # Typescript paths
└── webpack.config.js           # Webpack configuration

3rd party libraries

  • json-schema-to-ts - uses JSON-Schema definitions used by API Gateway for HTTP request validation to statically generate TypeScript types in your lambda's handler code base
  • middy - middleware engine for Node.Js lambda. This template uses http-json-body-parser to convert API Gateway event.body property, originally passed as a stringified JSON, to its corresponding parsed object
  • @serverless/typescript - provides up-to-date TypeScript definitions for your serverless.ts service file

Advanced usage

Any tsconfig.json can be used, but if you do, set the environment variable TS_NODE_CONFIG for building the application, eg TS_NODE_CONFIG=./tsconfig.app.json npx serverless webpack

Author

👤 Illia Shkurenko