sre-event-inc-urlshortener

Running application is on https://sre-event-inc-urlshortener.fly.dev/

Architecture Canvas

Value proposition

The application shortens, persists, and redirects to URLs provided by user.

Key Stakeholder

Internet users authenticated at the website.

Core Functions

Register and Sign In a user by email and password
Accepts an URL (f.e. https://google.com) from an authenticated (signed in) user and returns a shortened version that looks like https://sre-event-inc-urlshortener.fly.dev/elevenlettercode
Redirects to the URL with the shortened version for non-authenticated users
Supports editing the shortened URL with https://sre-event-inc-urlshortener.fly.dev/edit/elevenlettercode for authenticated users

Quality Requirements

Scalability to handle peak loads
Cost-effective performance maintenance strategies
Robust security practices to protect data and prevent unauthorised actions

Business Context

The system persists shortened URLs in the PostgreSQL application sre-event-inc-urlshortener-db on Fly.io
Running the system on Fly.io's trial plan may affect the response times of the system

Core Decisions

Reusing existing open source project https://github.com/SphericalKat/katbin
Use CI/CD pipeline with GitHub Actions

Low test coverage inherited

Technologies

Elixir Phoenix/Ecto for webservice
bcrypt_elixir/Rustler for password hashing
PostgreSQL for data persistance
Github Actions for deployment
Fly.io for hosting

Components/Modules

+-----------+    +------------+
| Webserver |----| PostgreSQL |
+-----------+    +------------+

Main webserver Routes:

Method	Path	Purpose	Authorization?
GET	/	Home page, to Register or Sign In	No
GET	/elevenlettercode/raw	Shows the full URL	No
GET	/v/elevenlettercode	Shows the shortened URL	No
GET	/elevenlettercode	Redirects to the full URL	No
GET	/edit/elevenlettercode	Edit the shortened URL	Yes

Risks and Missing Information

Application doesn't collect redirection metrics
Application doesn't have a real-time dashboard displaying usage metrics

CI/CD Pipeline and Deployment

Deployments are made in canary mode: old instances shut down only when new instance launches successfully.

GithubActions workflow:

.github/workflows/fly.yml
.github/workflows/test-branch.yml

Fly.io schema

./fly.toml

Deployment rules

Direct pushes to master are prohibited. You can make changes in a new branch, then make a PR to master
PR can be mered to master only when all tests pass

Times

Tests for a new branch takes ~1min
Deployment to production takes ~2 min

Local Setup

To start your Phoenix server:

Copy config/dev.secret.sample.exs to config/dev.secret.exs
Fill in the SMTP and database configuration in config/dev.secret.exs
Install dependencies with mix deps.get
Create and migrate your database with mix ecto.setup
Install Node.js dependencies with npm install inside the assets directory
Start Phoenix endpoint with mix phx.server

Now you can visit localhost:4000 from your browser.

Additional Documentation

Original repository: https://github.com/SphericalKat/katbin
Fly.io documentation: https://fly.io/docs
GithubActions documentation: https://docs.github.com/en/actions
Libraries docs: https://hexdocs.pm
Forum: https://elixirforum.com/c/phoenix-forum

IvanRublev / sre-event-inc-urlshortener