Tiny URL

Service for shortening URL by providing special aliases, which will redirect to actual URL. Similar services: tiny-url, bit-ly, short-url, etc

Originally idea came from course of system design. Included parts:

• Why do we need URL shortening?
  • Understood main idea of service
• Requirements and Goals of the System
  • Created minimal functionality of service
• Capacity Estimation and Constraints
• System APIs
  • Developed create and delete URL operations
  • Limit active URL count
• Database Design
  • Read about SQL vs NoSQL in order for choosing database type
  • Choose NoSQL database - MongoDB, because of weak relationship between entities. Also, it is easier to scale
  • Copy original schema of database
• Basic System Design and Algorithm
  • Developed algorithm of encoding original url with md5 and base64
• Data Partitioning and Replication
• Cache
  • Implement caching with Redis
  • Developed cache invalidation policy
• Load Balancer (LB)
• Purging or DB cleanup
  • Deleting expired URLs whenever it was accessed
• Telemetry
• Security and Permissions

Variables

Use these variables to run project in .env file

LOG_LEVEL=INFO

GIN_MODE=release    # For prod

MONGO_URI=mongodb://localhost:27017
MONGO_USER=<username>
MONGO_PASSWORD=<password>
MONGO_NAME=<db>

REDIS_URI=localhost:6379
REDIS_PASSWORD=<password>
REDIS_DB=<db>
REDIS_TTL=10s

AUTH_ACCESS_TOKEN_TTL=5m
AUTH_PASSWORD_SALT=<salt>
AUTH_JWT_KEY=<key>

URL_ALIAS_LENGTH=8
URL_DEFAULT_EXPIRATION=30
URL_COUNT_LIMIT=3

Commands

go generate - generate mock classes (in package)

make fmt - format whole project with gofmt (do it before any commit)

make swag - generate openapi documentation

make cover - run unit tests and show coverage report

make build - build project

make run - build and run project

Docker

Use dockerfiles in build directory for building images and running containers

Use build/Dockerfile for building images on unix systems. Use build/Dockerfile.multi for building images on non-unix systems