The Mower Backend

The mower backend is a backend application which is a communication link between the mower and the mobile application for reading and writing data.

Tech

The backend uses a number of open source projects to work properly:

• Node.js - Evented I/O for the backend
• Express - Fast node.js network app framework
• Awilix - Extremely powerful Dependency Injection (DI) container for JavaScript/Node
• Sequelize - Sequelize is a promise-based Node.js ORM tool for Postgres, MySQL, MariaDB, SQLite, DB2 and Microsoft SQL Server.
• pg - Non-blocking PostgreSQL client for Node.js.
• nodemon - nodemon is a tool that helps develop node.js based applications by automatically restarting the node application when file changes in the directory are detected.
• jsonwebtoken - is an access token standard that apps use to sign data transferred over the internet. It can also encrypt JSON payloads, and tokens may be signed with a private or public/private secret key. Through the jsonwebtoken module, this module offers Express middleware for verifying JSON Web Tokens
• aws-sdk - A SDK for AWS
• cognito-express - Amazon Cognito allows the backend to add functions for adding user, user sign up, sign in and to control access in the app.
• multer - multer is a middleware that handles uploading files in the application, multipart/form-data.
• multer-s3 - Streaming multer storage engine for AWS S3.
• google-cloud/vision - Google Cloud Vision API client for Node.js
• express-jwt - This module provides Express middleware for validating JWTs (JSON Web Tokens) through the jsonwebtoken module.
• dotenv - Dotenv is a zero-dependency module that loads environment variables from a .env file into process.env. Storing configuration in the environment separate from code is based on The Twelve-Factor App methodology.
• express-jwt-authz - Validate a JWTs scope to authorize access to an endpoint.
• fs - This module make file opertaion apis simple, you don't need to care the dir exits. and the api is same as node's filesystem.
• jwk-to-pem - Convert a json web key to a PEM for use by OpenSSL or crytpo.
• jwks-rsa - A library to retrieve signing keys from a JWKS (JSON Web Key Set) endpoint.
• node-fetch - A light-weight module that brings Fetch API to Node.js.path
• xmlhttprequest - node-XMLHttpRequest is a wrapper for the built-in http client to emulate the browser XMLHttpRequest object.

To start the app

Navigate to /backend folder and run following command:

docker-compose up --build

The app is now running on localhost:8080

To close the app

"ctrl + c" to stop the process in the terminal. To stop the containers run:

docker-compose down

To install npm pacakges

Step into: "/backend/backend-app" and run following command:

npm install <package name>

The API layer

• Endpoint documentation can be found here: Swagger
• Documentation for authentication endpoints can be found here: Swagger-authentication

The logic layer

Validation error codes

Code	Reason
invalidDataType	Thrown when a invalid data type is sent to the backend, e.g. the backend expects a Int but got a string
notAnArray	Thrown when the backend expects an array as an input, e.g. [ ]
invalidDataTypeInArray	Thrown when the data type in the array is not a number
invalidStatus	Thrown when the status is not "start bt" or "start auto" or "stop"

Database error codes

Code	Reason
dbUniqueConstraintError	Thrown when a unique constraint is violated in the database
dbForeignKeyConstraintError	Thrown when a foreign key constraint is violated in the database
dbError	Thrown when an internal error occurs in the database or when something unexpected happens, contact the admin

The data layer

License