README

Link: Keep and publish web links via HTML, RSS, and JSON

Welcome! Link is a demo application in use for RailsConf 2021 as part of the "Deploying your Rails Application to Kubernetes".

We'll use Link during the workshop to build a local Kubernetes environment and doing a three-step process for working with Kubernetes locally.

Prerequisites

Ruby and Rails

Link is a Rails application and requires Ruby 2.7.2. We use rbenv to run Ruby locally, but use whatever method you're comfortable with.

Link runs on Rails 6.1.3.1, the latest released version as of 2021-04-11.

NB: If you're running an older version of bundler, you will want to update that first: gem install bundler

PostgreSQL

Link uses PostgreSQL as a relational database. Any recent version should work. Your local instance of PostgreSQL may or may not require a password. The default role for a local installation does not.

• I installed PostgreSQL through Homebrew: brew install postgresql on macOS
• Linux users should use their system's package manager
• Windows users can download an interactive installer

Redis

Link uses Redis to run Sidekiq. The app is not doing much with Sidekiq, but we wanted to demonstrate it running as a concern to be aware of with running a Rails app in Kubernetes. NB: We're using the open source version of Redis, not Redis Enterprise. Any major version 4 or greater should be fine.

• macOS: Recommended install via Homebrew brew install redis
• Linux users should use their system's package manager
  • Ubuntu users, there's an official PPA
  • Redis is also available as a snap
• Windows: This appears to involve setting up the Windows Subsystem for Linux
  • Candidly, we're not Windows users, so unfortunately, we're not going to be much help here

Setup

For the RailsConf 2021 workshop, fork this repository, instead of cloning it.

tl;dr

• Clone it
• bundle install, yarn install
• Create a .env file and update it
• Create a config/database.yml file with the appropriate credentials and settings
• Create the databases and migrate them
• Fill-in seed data
• Start the app with Foreman
• Open the app

Stepwise

• Within the repository, bundle install then yarn install
• Create a .env file
  • cp .env.example .env
• Edit .env
  • Rails port: Search and replace for 3000 with an available port. E.g. I use 4100
  • Webpacker port: Search and replace for 3035 with an available port. I use 4135 for this
  • Adjust the REDIS_URL database number, if needed. The default is 15
• Review config/database.yml file for appropriate settings
  • We left this as is, change it on your fork as necessary
• Create the database
  • Empty DB: rails db:create
    • RAILS_ENV=test rails db:create
  • Migrate: rails db:migrate
• Fill-in seed data
  • rails db:seed
• Handle all of the database tasks in one go
  • rails db:setup
• Start the app with Foreman
  • (bundle exec) foreman start
• Open the app in your browser at the port you specified
  • http://localhost:3000/

Getting started with the app

• View the initial seed data on the page
• Create an account
• Create your own entries

Other key endpoints

NB: These are both unprotected endpoints. In a production application, you would have both of these wrapped with routing protection to check users for authentication and authorization.

• /sidekiq: Async job runner. Sidekiq will handle email, asynchronous API calls, or anything else you don't want your users to wait for
  • NB: We aren't doing anything with Sidekiq in this workshop beyond standing it up to demonstrate that it's something you need to consider and can handle with Kubernetes
• /admin: Adminsitrative interface. It's Administrate
  • In this case, it's an easy spot to page through all of the data

Running tests

There's a small test suite. Run it with rspec