By using Serverless Framework to deploy Lamdba functions to Amazon Web Services (AWS) this project is able to replace the original implementation created in the MongoDB, React Next.js, and Material UI Demo repository.
The Serverless API endpoints are produced by Express. Each endpoint interacts with MongoDB based on the action, method, and data. Apollo GraphQL provides a query language for this API. It also indirectly documents what the endpoints are and what kind of data can be returned from each query or mutation.
Finall Jest is used for creating a suite of unit tests for the API endpoints and also the underlying way in how data flows through the database.
This project requires that Serverless be installed as a global package.
npm install -g serverless
Run an npm install or update
npm i
Complete the following steps
-
Create a new application from the Serverless Dashboard then within the settings > parameters section; define the MONGODB_URI entry with the connection string of the MongoDB database
-
Ensure that the MongoDB database has the necessary IP addresses whitelisted for requests that go through the MongoClient
-
Deploy the project to CloudFormation using an applicable AWS provider by running
serverless deploy
The above should output the API endpoints and functions that are available for consumption. Any API testing platform such as Postman, Thunder Client, or the browser can be used on the following definitions.
| Serverless | AWS Lamdba |
|---|---|
| hello | aws-sites-dev-hello |
| graphql | aws-sites-dev-graphql |
| sites-dev-add | aws-sites-dev-sites-dev-add |
| sites-dev-delete | aws-sites-dev-sites-dev-delete |
| sites-dev-get | aws-sites-dev-sites-dev-get |
| sites-dev-list | aws-sites-dev-sites-dev-list |
| sites-dev-update | aws-sites-dev-sites-dev-update |
Functions can be invoked from the Serverless Dashboard or locally (browser or command line) by running either of the following
serverless offline start
serverless invoke local -function SERVERLESS_FUNCTION_NAME
There are 3 ways of accessing the Apollo GraphQL functionality.
- Apollo GraphQL Explorer Sandbox
- Apollo GraphQL Playground (local)
- Serverless Apollo GraphQL
The above ways of interacting with Apollo GraphQL depend on running in conjunction with Serverless. Start a local instance of the API endpoints.
serverless offline start
Optionally start Explorer Sandbox or Playground by running either command found below. Note that by default both instances bind to port 4000, at http://localhost:4000/graphql . They also read the .env file for the LAMBDA_FUNCTIONS_URI environment variable which by default points to http://localhost:3000/
npm run apollo-server
npm run apollo-playground
The local endpoint is http://localhost:3000/dev/graphql and it accepts operations (query or mutation) using the POST method. Before using this method of accessing the API do the following:
- Create a .env.development file and define the LAMBDA_FUNCTIONS_URI environment variable
- Create a .env.production file and define the LAMBDA_FUNCTIONS_URI environment
Naturally these variables should point to either http://localhost:3000/ or https://YOUR_API.execute-api.-YOUR_REGION-.amazonaws.com/
The production environment variable is only used if deploying using the following
serverless deploy --stage production
The /tests folder contains a number of unit tests. They are separated into the callbacks and endpoints directories.
Callbacks are basically the integration with the provided test MongoDB database. In other words the Express callbacks are testing if the data passed to the Serverless functions are correctly making changes to the test database collection.
The test MongoDB database is provided by mongodb-memory-server.
Endpoints are unit tests, ensuring that all the expected URLs return a status, which in most cases is something either than a 404 Not Found. These unit tests also expect that the Express endpoints only accept the correct request method, i.e. GET, POST, etc.
The Express endpoints are simulated by supertest.
Finally the coverage report, located in /coverage/lcov-report/index.html shows how much of the Serverless functions are being covered in these unit tests.
All terms used are copyright to their original authors.