G-Bank

This repository contains the codes of the Backend Master Class course.

This course is a step-by-step guide on how to design, develop, test and deploy a backend web service from scratch.

The backend service is a simple bank system that allows:

• Create and manage accounts and users.
• Record all balance changes to each account.
• Make transfers between accounts.

Course Outline

Section 1: Working with database [Postgres]

• Design the database schema
• Generate codes to talk to the DB
• Understand the DB isolation levels
• How to use Docker
• How to use Git and GitHub Actions to automate the CI/CD process

Section 2: Building RESTful HTTP JSON API [Gin]

• Build a RESTful API using Gin
• Loading app configs
• Mocking DB for more robust unit tests
• Handling errors
• Authentication and authorization using JWT & PASETO

Section 3: Deploying the application to production [Kubernetes + AWS]

• Build app with Docker and deploy to Kubernetes Cluster on AWS
• Setup free tier AWS account
• Create a production DB on AWS RDS
• Store and retrieve production secrets using AWS Secrets Manager
• Create a Kubernetes Cluster with EKS
• Use GitHub Actions to automatically build and deploy the image to the Kubernetes Cluster
• Buy a domain name and route traffics to the service
• Secure with HTTPS and auto-renew SSL certificates from Let's Encrypt

Section 4: Advanced Backend Topics [Sessions + gRPC]

• Managing user sessions
• Building gRPC API
• Using gRPC Gateway to serve both gRPC and HTTP requests at the same time
• Embedding Swagger UI to document the API
• Updating a record using optional parameters
• Writing structured logger HTTP middlewares and gRPC interceptors

Section 5: Asynchronous processing with background workers [Asynq + Redis]

• Asynchronous processing using background workers and Redis as its message queue
• Create and send emails to users via Gmail SMTP server
• Writing Unit Test for our gRPC services that might involve multiple dependencies at once

Section 6: Improve the stability and security of the server

• Improve stability and security of the server
• Updating dependenby packages to the latest version
• Use Cookies to make the refresh token more secure
• How to gracefully shutdown the server to protect the processing ressources

Docs

• Lecture #0: Simple Bank
• Lecture #1: Database Design
• Lecture #2: Install & use Docker & Postgres
• Lecture #3: How to write & run DB migration in Golang
• Lecture #4: Generate CRUD Golang code from SQL
• Lecture #5: Unit Testing in Go db CRUD
• Lecture #6: DB Transaction in Golang
• Lecture #7: DB Transaction lock & how to handle deadlock
• Lecture #8: How to avoid DB Deadlock
• Lecture #9: Transaction isolation level
• Lecture #10: Github actions
• Lecture #11: Implement RESTful API
• Lecture #12: Load Config from file & env vars
• Lecture #13: Mock DB for testing HTTP API
• Lecture #14: Custom params validator
• Lecture #15: Add user table with unique & foreign key constraints
• Lecture #16: handle db errors
• Lecture #17: Hash Password
• Lecture #18: Stronger Unit tests
• Lecture #19: Why PASETO is better than JWT
• Lecture #20: Create & verify JWT & PASETO
• Lecture #21: Implement login API with paseto & jwt
• Lecture #22: How to implement authentication middleware
• Lecture #23: Build a minimal golang docker image
• Lecture #24: How to connect containers in the same docker network
• Lecture #25: How to use Docker compose
• Lecture #26: How to create a free tier AWS account
• Lecture #27: Build & push docker image to AWS ECR
• Lecture #28: How to create a production DB on AWS RDS
• Lecture #29: Store & retrieve production secrets with AWS secrets manager
• Lecture #30: How to create an AWS EKS Cluster
• Lecture #31: Kubectl & k9s
• Lecture #32: Deploy a web app to Kubernetes on aws
• Lecture #33: Register a domain & set up A-record using Route 53
• Lecture #34: How to use Ingress to route traffics to different services in K8s
• Lecture #35: Automatic issue TLS certificates in Kubernetes with Let's Encrypt
• Lecture #36: Automatic deploy to Kubernetes with Github action
• Lecture #37: how to manage user session with refresh token
• Lecture #38: Generate DB docs
• Lecture #39: Introduction to gRPC
• Lecture #40: Define gRPC API and generate Go code with protobug
• Lecture #41: How to run gRPC server
• Lecture #42: Implement gRPC API
• Lecture #43: Write code once, serve both gRPC & HTTP requests
• Lecture #44: Meta data in gRPC
• Lecture #45: Generate & serve Swagger with Go
• Lecture #46: Embed static frontend files inside Golang backend
• Lecture #47: gRPC params validation
• Lecture #48: Run DB migration with Go
• Lecture #49: Partial update & null params in go with sqlc
• Lecture #50: Build gRPC update with optional parameters
• Lecture #51: Add authorization to protect gRPC API
• Lecture #52: Write structured logs for gRPC APIs
• Lecture #53: HTTP logger middleware
• Lecture #54: Process async tasks with background workers
• Lecture #55: Integrate async worker to Go web server
• Lecture #56: Send async tasks to Redis within a DB transaction
• Lecture #57: How to handle errors and print logs for Go Asynq workers
• Lecture #58: The importance of delay in async tasks
• Lecture #59: How to send emails in go
• Lecture #60: How to skip test
• Lecture #61: Email verification
• Lecture #62: Implement email verfication API
• Lecture #63: How to unit test gRPC services
• Lecture #64: Unit test gRPC auth
• Lecture #65: Config sqlc version 2
• Lecture #66: Switch DB driver to pgx
• Lecture #67: Handle DB erros with PGX
• Lecture #68: Docker compose
• Lecture #69: Golang binary packages