expense-service

Pre-requisites

• Docker Desktop (for local dynamoDB emulation)

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

Locally

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

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

Check the sls invoke local command documentation for more information.

Alternatively, host the service locally with serverless-offline

• npm run serve

This command runs sls offline with local parameters. See package.json for more info.

Database

DynamoDB is used as the backing store. Run the npm run start-db command to locally run a DynamoDB instance. docker-compose is used to run the db container from src/utils/local-db

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/hello' \
--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
│   │   ├── hello
│   │   │   ├── 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