vedant-204/open-flights-deployment

Fork for deployment using docker and k8s along with added monitoring, caching and error logging services

OpenFlights

A flight reviews app built with Ruby on Rails and React.js

This app is intended to be a simple example of a CRUD app built with Ruby on Rails and React.js using Webpacker.

---

---

This app uses:

• Ruby version: 2.7
• Rails version: 6.0.3.4
• Database: postgresql
• React version: 16.12.0
• React Hooks API
• React Context API

Running it locally

• run bundle exec rails db:prepare
• run npm install or yarn install
• run bundle exec rails s
• in another tab run ./bin/webpack-dev-server (optional)
• in another tab run sidekiq (optional, but necessary for things like password reset emails)
• navigate to http://localhost:3000

Environment Variables

If you want functionality like password reset emails to work locally, you'll need to set the following environment variables in config/application.yml with your own unique values:

ROOT_URL: http://localhost:3000
SENDGRID_API_KEY: xxxxxxxxxxxxxx
SENDGRID_USERNAME: xxxxxxxxxxxxxx
SENDGRID_PASSWORD: xxxxxxxxxxxxxx
DEFAULT_FROM_EMAIL: [email protected]

Routes

             Prefix Verb   URI Pattern                           Controller#Action
               root GET    /                                     pages#index
    api_v1_airlines GET    /api/v1/airlines(.:format)            api/v1/airlines#index
                    POST   /api/v1/airlines(.:format)            api/v1/airlines#create
 new_api_v1_airline GET    /api/v1/airlines/new(.:format)        api/v1/airlines#new
edit_api_v1_airline GET    /api/v1/airlines/:slug/edit(.:format) api/v1/airlines#edit
     api_v1_airline GET    /api/v1/airlines/:slug(.:format)      api/v1/airlines#show
                    PATCH  /api/v1/airlines/:slug(.:format)      api/v1/airlines#update
                    PUT    /api/v1/airlines/:slug(.:format)      api/v1/airlines#update
                    DELETE /api/v1/airlines/:slug(.:format)      api/v1/airlines#destroy
     api_v1_reviews POST   /api/v1/reviews(.:format)             api/v1/reviews#create
      api_v1_review DELETE /api/v1/reviews/:id(.:format)         api/v1/reviews#destroy
                    GET    /*path(.:format)                      pages#index

---

Api V2 (Graphql)

Get Airlines#index

query Airlines {
  airlines {
    id
    name
    imageUrl
    slug
    averageScore
    reviews {
      id
      title
      description
      score
    }
  }
}

Get Airlines#show

query Airline {
  airline(slug:) {
    id
    name
    imageUrl
    slug
    averageScore
    reviews {
      id
      title
      description
      score
    }
  }
}

Create Review

mutation {
  createReview(
    title: "test",
    description: "test",
    score: 1,
    airlineId: 1
  ) {
    id
    title
    description
    score
    airlineId
    error
    message
  }
}

Destroy Review

mutation {
  destroyReview(id:) {
    message
    error
  }
}

---

How to rebuild this app from scratch (*WORK IN PROGRESS)

For an up to date, full step-by-step guide on how to rebuild this app from scratch, check out this article I've put together.

Getting Started: Creating a New Rails App With React & Webpacker

First things first, let's create a brand new rails app. We can do this from the command line by doing rails new app-name where app-name is the name of our app, however we are going to add a few additional things. We need to add --webpack=react to configure our new app with webpacker to use react, and additionally I'm going to add --database=postgresql to configure my app to use postgres as the default database. so the final output to create our new app will look like this:

rails new open-flights --webpack=react --database=postgresql

Once this finishes running, make sure to cd into the directory of your new rails app (cd open-flights), then we can go ahead and create the database for our app by entering the following into our command line:

bundle exec rails db:create

Models

Our data model for this app will be pretty simple. Our app will have airlines, and each airline in our app will have many reviews.

For our airlines, we want to have a name for each airline, a unique url-safe slug, and an image_url for airline logos (Note: I'm not going to handle file uploading in this article, instead we will just link to an image hosted on s3).

For our reviews, we want to have a title, description, score, and the airline_id for the airline the review will belong to. The scoring system I'm going to use for our reviews will be a star rating system that ranges from 1 to 5 stars; 1 being the worst score and 5 being the best score.

So from our command line we can enter the following generators to create our airline and review models in our app:

rails g model Airline name slug image_url

rails g model Review title description score:integer airline:belongs_to

This will create two new files in our db/migrations folder; one for airlines:

class CreateAirlines < ActiveRecord::Migration[5.2]
  def change
    create_table :airlines do |t|
      t.string :name
      t.string :slug
      t.string :image_url

      t.timestamps
    end
  end
end

and one for reviews:

class CreateReviews < ActiveRecord::Migration[5.2]
  def change
    create_table :reviews do |t|
      t.string :title
      t.string :description
      t.integer :score
      t.belongs_to :airline, foreign_key: true

      t.timestamps
    end
  end
end

Additionally, we should now have airline and review model files created for us inside of our app/models directory. Because we used airline:belongs_to when we generated our review model, our Review model should already have the belongs_to relationship established, so our this model so far should look like this:

class Review < ApplicationRecord
  belongs_to :airline
end

We need to additionally add has_many :reviews to our airline model. Once we do, our airline model should look like this:

class Airline < ApplicationRecord
  has_many :reviews
end

At this point, we can go ahead and migrate our database:

rails db:migrate

Once you run that, you should see a new schema.rb file created within the db folder in our app. Your schema file should now look something like this:

ActiveRecord::Schema.define(version: 2019_12_26_200455) do
  enable_extension "plpgsql"

  create_table "airlines", force: :cascade do |t|
    t.string "name"
    t.string "slug"
    t.string "image_url"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
  end

  create_table "reviews", force: :cascade do |t|
    t.string "title"
    t.string "description"
    t.integer "score"
    t.bigint "airline_id"
    t.datetime "created_at", null: false
    t.datetime "updated_at", null: false
    t.index ["airline_id"], name: "index_reviews_on_airline_id"
  end

  add_foreign_key "reviews", "airlines"
end

So now for our airline model, we need to do a couple things. First off, I want to add a before_create callback method that creates a unique slug based off of the airline's name when we create a new airline. To do this, we can add a new slugify method with a before create callback to our airline model like this:

class Airline < ApplicationRecord
  has_many :reviews

  before_create :slugify

  def slugify
    self.slug = name.downcase.gsub(' ', '-')
  end
end

This slugify method will take the name of an airline, convert any uppercase characters to lowercase, replace any spaces with hyphens, and set this value as our slug before saving the record.

Actually, I think we can simplify this method further by just calling parameterize on our name attribute instead of using downcase and gsub:

class Airline < ApplicationRecord
  has_many :reviews

  before_create :slugify

  def slugify
    self.slug = name.parameterize
  end
end

This parameterize method should handle both downcasing characters and replacing spaces with hyphens for us. Of course, we can quickly test this out from our rails console to confirm:

'Fake AIRline Name     1'.parameterize
# => "fake-airline-name-1"

So now if/when we create a new airline, for example "United Airlines", this will convert the name to united-airlines and save it as the unique slug for that airline.

Additionally, we need to create a method that will take all of the reviews that belong to an airline and get the average overall rating. We can add an avg_score method to our model like this:

class Airline < ApplicationRecord
  ...

  def avg_score
    reviews.average(:score).to_f.round(2)
  end
end

This method will return 0 if an airline has no reviews yet. Otherwise it will get the sum of all the review scores for an airline divided by the total number of reviews for that airline to get the average rating.

So our full Airline model with our slugify method and avg_score method should now look like this:

class Airline < ApplicationRecord
  has_many :reviews

  before_create :slugify

  def slugify
    self.slug = name.parameterize
  end

  def avg_score
    reviews.average(:score).to_f.round(2)
  end
end

Seeding Our Database

Now that we have got our models created, let's go ahead and seed our database with some data! We can add this to the seeds.rb file located inside of our db folder:

Airline.create([
  { 
    name: "United Airlines",
    image_url: "https://open-flights.s3.amazonaws.com/United-Airlines.png"
  }, 
  { 
    name: "Southwest",
    image_url: "https://open-flights.s3.amazonaws.com/Southwest-Airlines.png"
  },
  { 
    name: "Delta",
    image_url: "https://open-flights.s3.amazonaws.com/Delta.png" 
  }, 
  { 
    name: "Alaska Airlines",
    image_url: "https://open-flights.s3.amazonaws.com/Alaska-Airlines.png" 
  }, 
  { 
    name: "JetBlue",
    image_url: "https://open-flights.s3.amazonaws.com/JetBlue.png" 
  }, 
  { 
    name: "American Airlines",
    image_url: "https://open-flights.s3.amazonaws.com/American-Airlines.png" 
  }
])

And then we can seed our database by running the following command in our terminal:

rails db:seed

Now if we jump into our rails console with rails c we should be able to see our new data in the database:

Airline.first
# => #<Airline id: 1, name: "United Airlines", slug: "united-airlines", image_url: "https://open-flights.s3.amazonaws.com/United-Airlines.png", created_at: "2019-12-26 23:02:58", updated_at: "2019-12-26 23:02:58">

Notice that even though we only included the name and image_url in our seed data, we additionally have a slug value (in this case "united-airlines") because we added that slugify method to our airline model. We will use this slug shortly as the paramater to find records by in our controllers, instead of using the id param.

Serializers: Building Our JSON API

For this app we are going to use fast_jsonapi, a gem created by the Netflix engineering team. If you have ever used Active Model Serializer (AMS), you will likely notice some similarities.

with fast_jsonapi, we can create the exact structure for the data we want to expose in our api, and then use that when we render json from within our controllers.

Let's install the fast_jsonapi gem, by adding it to our Gemfile:

gem 'fast_jsonapi'

Then we can install it with bundle install from our terminal:

bundle install

Now we can use a generator to create a new airline serializer and review serializer, passing along the specific attributes we want to expose in our api:

rails g serializer Airline name slug image_url

rails g serializer Review title description score airline_id

This will create a new serializer folder in our app and create a new airline serializer that should so far look like this:

class AirlineSerializer
  include FastJsonapi::ObjectSerializer
  attributes :name, :slug, :image_url
end

And a reviews serializer that should look like this:

class ReviewSerializer
  include FastJsonapi::ObjectSerializer
  attributes :title, :description, :score, :airline_id
end  

For our airlines serializer, we want to include the relationship with reviews in our serialized json. We can add this simply by adding has_many :reviews into our serializer. So then our serializer should look like this:

class AirlineSerializer
  include FastJsonapi::ObjectSerializer
  attributes :name, :slug, :image_url
  has_many :reviews
end

Let's take a quick look at how we can use our serializers now to structure our api. If we jump into a rails console (rails c) in our terminal, let's get the first airline from our database. Then we can initialize a new instance of our airline serializer with that record and return the result as serialized json:

# Get the first airline record from our database
airline = Airline.first
=> #<Airline id: 1, name: "United Airlines", slug: "united-airlines", image_url: "https://open-flights.s3.amazonaws.com/United-Airlines.png", created_at: "2019-12-26 23:02:58", updated_at: "2019-12-26 23:02:58">

# Serialized JSON
AirlineSerializer.new(airline).serialized_json
=> "{\"data\":{\"id\":\"1\",\"type\":\"airline\",\"attributes\":{\"name\":\"United Airlines\",\"slug\":\"united-airlines\",\"image_url\":\"https://open-flights.s3.amazonaws.com/United-Airlines.png\"},\"relationships\":{\"reviews\":{\"data\":[]}}}}"

# Formatted JSON
AirlineSerializer.new(airline).as_json
=> {
  "data" => {
    "id" => "1", 
    "type" => "airline", 
    "attributes" =>  {
      "name" => "United Airlines", 
      "slug" => "united-airlines", 
      "image_url" => "https://open-flights.s3.amazonaws.com/United-Airlines.png"
    }, 
    "relationships" => {
      "reviews" => {
        "data" => []
      }
    }
  }
}

In the above examples, you can see that the only attributes shared within the attributes section are those that we have explicitly declared in our airline seriaizer.

Controllers

Our app is going to have three controllers: an airlines controller, a reviews controller and a pages controller. Our pages controller will have a single index action that I'm going to use as the root path of our app. I'm also going to use Pages#index as a sort of catch-all for any requests outside of our api. This will come in handy once we start using react-router in a little, as we will need to be able to match routes to different components.

For our airlines and reviews controllers, we are going to namespace everything under api/v1. Again, this will give us an easy way to manage routing from both the react side of our app and the rails side once we additionally start using react-router in a moment.

For example, if a user navigates to /airlines in our app, on the react side we can load the necessary components to show a list of all airlines, and on the back end we can make the request to our Airline#index action in our controller as /api/v1/airlines to get a list of all of the airlines from our api.

Routes

Let's actually go ahead and set up our routes, adding our root path and our namespaced api resources:

Rails.application.routes.draw do

  root 'pages#index'

  namespace :api do
    namespace :v1 do
      resources :airlines, param: :slug
      resources :reviews, only: [:create, :destroy]
    end
  end

  get '*path', to: 'pages#index', via: :all
end   

Notice that I added param: :slug to our airlines resources so that we can use our slugs as the primary param for airlines instead of using id.

Airlines Controller

Inside of app/controllers, let's create a new api folder, and inside of that, a new v1 folder, and then inside of that let's create a new airlines controller, namespaced underApi::V1:

module Api
  module V1
    class AirlinesController < ApplicationController
    end
  end
end

Airlines#index

Now let's add an index method to our new controller. All we need to do for this method is get all of the airlines from our database, then render the data as JSON using our AirlineSerializer.

To get all of our airlines, we can simply call all on our Airline model like so:

airlines = Airline.all

Then we can pass our airlines variable as an argument into a new instance of our AirlineSerializer and return our data as serialized JSON like so:

AirlineSerializer.new(airlines).serialized_json

So putting these two steps together, and then rendering the result as JSON from our controller, our index method should look like this:

module Api
  module V1
    class AirlinesController < ApplicationController
      def index
        airlines = Airline.all

        render json: AirlineSerializer.new(airlines).serialized_json
      end
    end
  end
end

Airlines#show

Our show method will also be pretty simple. For this we just need to find a specific airline, not by its id, but using it's slug as the param. We can do this by calling find_by on our Airline model and searching for a record that has a matching slug, like so:

airline = Airline.find_by(slug: params[:slug])

Then, we will again render the resulting JSON using our AirlineSerializer. So our show method should look like this:

module Api
  module V1
    class AirlinesController < ApplicationController
      ...
      
      def show
        airline = Airline.find_by(slug: params[:slug])

        render json: AirlineSerializer.new(airlines).serialized_json
      end
    end
  end
end

Airlines#create

Before we add our create method, let's use strong paramaters to create a whitelist of allowed parameters when creating a new airline in our app. For now we will allow only name and image_url:

module Api
  module V1
    class AirlinesController < ApplicationController
      
      ... 

      private

      def airline_params
        params.require(:airline).permit(:name, :image_url)
      end
    end
  end
end

Then we can go ahead and add our create method. For this, we will simply initialize a new instance of Airline, passing in our airline_params. If everything is valid and saves, we will render data for our new airline again using our airline serializer, otherwise we will return an error:

module Api
  module V1
    class AirlinesController < ApplicationController

      ...

      def create
        airline = Airline.new(airline_params)

        if airline.save
          render json: AirlineSerializer.new(airline).serialized_json
        else
          render json: { error: airline.errors.messages }, status: 422
        end
      end

      private

      def airline_params
        params.require(:airline).permit(:name, :image_url)
      end
    end
  end
end

---

This README is still being written - check back soon!

---

License

Copyright (c) 2020 zayneio

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.