kemalelmizan / si-backend

Startup Incubation Class - Backend Setup

Github Project Setup

1. Create new repo with name <your_app>-api or <your_app>-backend

Heroku Project setup

1. Create new app with name <your_app>-api or <your_app>-backend
2. Connect to previously created github repo
3. Download heroku CLI tools
4. Install heroku postgres plugin

Local Project setup

1. git clone https://github.com/kemalelmizan/<your_app>-api.git
2. npm init
3. Fill details
4. npm i --save express
5. npm i --save body-parser
6. npm i --save pg
7. npm i --save db-migrate
8. npm i --save db-migrate-pg
9. Add "start": "node index.js" in package.json scripts

Database migration setup

1. npm i -g db-migrate
2. db-migrate -v
3. Add database.json config file
4. DATABASE_URL=postgres://xxx db-migrate create <table_name> --sql-file -e production
5. Repeat previous step for every tables
6. Fill in SQL up and down script in ./migrations/sqls
7. DATABASE_URL=postgres://xxx db-migrate up -e production

API setup

1. Setup express routers
2. Setup queries
3. Generate random tokens by Array(64).fill(0).map(x => Math.random().toString(36).charAt(2)).join('')
4. Setup API_TOKEN in heroku
5. DATABASE_URL=postgres://xxx SSL=true npm start

Heroku CLI Commands

1. heroku auth:login
2. heroku auth:whoami
3. heroku apps
4. heroku addons --all
5. heroku logs --tail -a si-backend
6. to restart app: heroku restart -a si-backend

Local Docker Postgres Dev DB Setup

1. Install and run docker
2. docker -v
3. docker run -p 5432:5432 --name si-backend -e POSTGRES_PASSWORD=sibackend -d postgres
4. docker ps -a
5. to start container: docker start si-backend
6. Add dev environment in database.json
7. db-migrate up -e dev
8. DATABASE_URL=postgres://postgres:sibackend@localhost:5432/postgres npm start
9. Create DB migration using local docker: db-migrate create <table_name> --sql-file -e dev

Generate User Specific Token (Postgres)

1. db-migrate create users --sql-file -e dev
2. Fill in SQL up and down script in ./migrations/sqls
3. db-migrate down -e dev
4. db-migrate up -e dev
5. DATABASE_URL=postgres://postgres:sibackend@localhost:5432/postgres API_TOKEN=abc npm start

ERD

Modular Development

1. Single Responsibility Principle
2. Add folders according to folder structure
3. Restructure index.js into corresponding controllers and models
4. Add controller/helper/response.js to wrap the response
5. Add controller/helper/validation.js for validation libraries
6. Add controller/access/admin.js, buyer.js and seller.js for access control matrix
7. Add controller/auth/api.js for API_TOKEN validation
8. Separate controller/auth/user.js and model/auth/user.js
9. Add controller/auth/access.js to validate module access rights
10. Set environment variables in postman for easy access, add host, API_TOKEN, user_email and access_token

Passport & Authentication

1. npm install --save dotenv
2. Create .env file
3. Register Google API Credential to get Client ID GOOGLE_KEY and Client secret GOOGLE_SECRET here

https://console.developers.google.com/apis/credentials

1. Add following values to .env file

SESSION_SECRET=abcd
PORT=8080
DATABASE_URL=postgres://postgres:sibackend@localhost:5432/postgres
SSL=false
API_TOKEN=abc
GOOGLE_KEY=xxx.apps.googleusercontent.com
GOOGLE_SECRET=xxx
CLIENT_ORIGIN=http://localhost:3000

1. npm install --save passport
2. npm install --save passport-google-oauth
3. const googleAuth = passport.authenticate('google', { scope: ['profile'] }) in index.js
4. Route triggered by the React client app.get('/google', googleAuth)
5. Routes that are triggered by callbacks from OAuth providers once the user has authenticated successfully

app.get("/google/callback", googleAuth, (req, res) => {
  const io = req.app.get("io");
  const user = {
    name: req.user.displayName,
    photo: req.user.photos[0].value.replace(/sz=50/gi, "sz=250")
  };
  io.in(req.session.socketId).emit("google", user);
  res.end();
});

1. Setup socket

app.use((req, res, next) => {
  req.session.socketId = req.query.socketId;
  next();
});

1. Clone https://github.com/funador/react-auth-client for frontend test, change API_URL in config.js to http://localhost:8080

Module Specific Setup

• User
• Product
• Store
• Cart
• Order

Homework for next session

• Finish CRUD for each modules (model, controller and route)
• Create all requests template for CRUD in postman

To be covered in next sessions

1. unit tests and test coverage
2. third party libraries: file upload, nodemailer
3. third party APIs: mailgun, user ID APIs https://github.com/sahat/hackathon-starter#obtaining-api-keys
4. ngrok for public testing
5. caching using redis
6. timeout and circuit breaker handling
7. security: penetration testing, injection, OWASP
8. documentation: swagger

Links and docs

1. Heroku postgres docs
2. db-migrate docs
3. Express API
4. Express middleware
5. Docker Cheat Sheet