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Create And Deploy A Rails App

Step 1: Change to your home directory

cd stands for change directory.

Windows
Type this in the terminal:
cd c:\Sites

cd c:\Sites sets our Sites directory to our current directory.

Mac or Linux
Type this in the terminal:
cd ~

cd ~ sets our home directory to our current directory.

Step 2: Create a railbridge directory

Type this in the terminal:
mkdir railsbridge

mkdir stands for make directory (folder).

We've made a folder called railsbridge.

Step 3: Change to your new railsbridge directory

Type this in the terminal:
cd railsbridge

Step 4: Create a new Rails app

Type this in the terminal:
rails new test_app

The command's output is voluminous, and will take some time to complete, with a long pause in the middle, after all the 'create...' statements ending in 'bundle install'. When it fully completes, it will return you to your home prompt. Look for the 'Your bundle is complete!' message just above.

Type this in the terminal:
cd test_app

On Linux, you may have to enable this line in your Gemfile:

gem 'therubyracer', :platforms => :ruby

Just delete the '#' in front of the statement, then save the file. All that is left is to do a bundle install

Type this in the terminal:
bundle install
Type this in the terminal:
rails server

In Windows, you may need to let Ruby and Rails communicate through your firewall. Say yes to the popup.

Shortcut: Just type 'rails s'

Throughout your Rails programming career you're going to type rails server a lot. In fact, you'll type this so much that DHH (David Heinemeier Hansson, creator of Ruby on Rails) and the Rails Core team decided to save you 5 keystrokes per server restart. Simply typing rails s is the same as rails server.

The first command should produce no output. If rails server starts up with no errors, you're golden! It'll look something like this:

Approximate expected result:
=> Booting WEBrick
=> Rails 4.0.x application starting in development on http://0.0.0.0:3000
=> Call with -d to detach
=> Ctrl-C to shutdown server
[2021-09-30 21:04:12] INFO  WEBrick 1.3.1
[2021-09-30 21:04:12] INFO  ruby 1.9.3 (2021-11-10) [x86_64-darwin10.4.2]
[2021-09-30 21:04:12] INFO  WEBrick::HTTPServer#start: pid=24805 port=3000
The greyed-out text may differ and is not important.

If it does, congratulations! You've successfully installed Ruby AND Rails and started your server.

If it doesn't work, ask a TA for help.

  • In your browser, go to http://localhost:3000

  • Back in the Terminal window where you ran rails server, type Control-C (don't type this into the console, but hold the Control and C keys at the same time) to kill(stop) the server. Windows will ask "Terminate batch job (Y/N)?". Type "Y".

On Windows, sometimes Control-C doesn't work. In that case, look for the key called 'Break' or 'Pause' and press Control-Break, then answer Y at the prompt. If there is no Pause/Break key on your keyboard, you can run ruby script/rails server instead of rails server which should allow Control-C to stop the server.

Step 5: Generate a database model

If your prompt doesn't already show that you are (still) in the test_app folder

Type this in the terminal:
cd test_app
Type this in the terminal:
    rails generate scaffold drink name:string temperature:integer
Type this in the terminal:
    rake db:migrate
Type this in the terminal:
    rails server

Note: the above are three separate commands. Type each line into the terminal separately, not as one single command.

Wait until your console shows that the Webrick server has started (just like before). Then, in the browser, visit http://localhost:3000/drinks

  1. Click on "New drink"
  2. Enter Cappuccino for the name
  3. Enter 135 for the temperature.
  4. Click on "Create Drink".

(The window where you ran rails server will display debugging information as you do this.)

You should see:

In your terminal, Hold Control and hit C (or on Windows, Control-Break, Y) to stop the rails server.

Step 6: Use git

If your prompt doesn't already show that you are (still) in the test_app folder

Type this in the terminal:
cd test_app
Type this in the terminal:
    git init
Expected result:
Initialized empty Git repository in c:/Sites/railsbridge/test_app/.git/
Type this in the terminal:
git add -A

With Git, there are usually many ways to do very similar things. git add adds changes in your working directory to the local repository.

  • git add foo.txt adds a file named foo.txt
  • git add . ("git add dot") adds all new files and changed files, but does not remove deleted files

  • git add -A adds everything, including deletions

    "Adding deletions" may sound weird, but if you think of a version control system as keeping track of changes, it might make more sense.

Type this in the terminal:
git commit -m "initial commit"
Expected result:
a lot of lines like create mode 100644 Gemfile
Type this in the terminal:
git log
Expected result:
(Your git name and "initial commit" message.)

Step 7: Deploy your app to Heroku

Step 7.1: Create a Heroku application from this local Rails application.

The very first time you use heroku you must enter your Heroku email address and password. Your password may not be shown as you type it, but don't worry, it's being entered! If you have already provided your credentials before, you won't be prompted for them again.

Type this in the terminal:
heroku create
Expected result:
Enter your Heroku credentials.
Email: myemail@example.com
Password:
Uploading ssh public key /Users/smei/.ssh/id_rsa.pub
Creating floating-winter-18... done, stack is cedar
http://floating-winter-18.heroku.com/ | git@heroku.com:floating-winter-18.git
Git remote heroku added

Heroku apps are automatically given lyrical names that look like '[adjective]-[noun]-[number]'. Each name is unique.

Type this in the terminal:
git remote show
Expected result:
heroku

If you get messages here complaining about public keys it's probably due to some confusion with SSH key usage by another app on your computer. Call a volunteer over to help you figure it out. Luckily this only needs to be done the first time you create a Heroku app.

Step 7.2: Prepare your rails app for deploying to Heroku

Launch your text editor and open the "Gemfile" file located inside of your test_app folder. (On Windows, this should be in C:\Sites\railsbridge\test_app and on Linux/OS X, it should be under ~/railsbridge/test_app.)

Inside this file, change the line:

gem 'sqlite3'

To this:

group :development, :test do
  gem 'sqlite3'
end
group :production do
  gem 'pg'
  gem 'rails_12factor'
end

Save the file.

Why Sqlite (sqlite3) and PostgreSQL (pg)?

SQLite and PostgreSQL are different kinds of databases. We're using SQLite for our development and test environments because it's simple to install. We're using PostgreSQL in our production environment because Heroku has done the hard work of installing it for us and it's more powerful than SQLite. We have seperate test, development and production databases by default in Rails.

Type this in the terminal:
bundle install --without production

Again, wait for the console prompt, and look for the 'Your bundle is complete!' message just above. If this fails, get a volunteer to help you edit config/environments/production.rb

Step 7.3: Set the root route

Use your editor to open the file routes.rb (C:\sites\railsbridge\test_app\config\routes.rb or ~/railsbridge/test_app/config/routes.rb) and find the line containing:

# root 'welcome#index'

Remove this line and replace it with:

root 'drinks#index'

Note that you must remove the leading '#', as lines that start with a # are comments and will not have any effect.

Step 7.4: Add the changes to git

Type this in the terminal:
git add -A
git commit -m "Updates for heroku deployment"

Step 7.5: Deploy (push) to heroku

Type this in the terminal:
git push heroku master

It may ask: "The authenticity of host 'heroku.com (75.101.145.87)' can't be established. RSA key fingerprint is 8b:48:5e:67:0e:c9:16:47:32:f2:87:0c:1f:c8:60:ad. Are you sure you want to continue connecting (yes/no)?" Type yes and hit enter.

Expected result:
The authenticity of host 'heroku.com (75.101.145.87)' can't be established.
RSA key fingerprint is 8b:48:5e:67:0e:c9:16:47:32:f2:87:0c:1f:c8:60:ad.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added 'heroku.com,75.101.145.87' (RSA) to the list of known hosts.
Counting objects: 60, done.
Compressing objects: 100% (54/54), done.
Writing objects: 100% (60/60), 79.03 KiB, done.
Total 60 (delta 10), reused 0 (delta 0)
-----> Heroku receiving push
-----> Rails app detected
       Compiled slug size is 080K
-----> Launching...... done
       App deployed to Heroku
To git@heroku.com:floating-winter-18.git
 * [new branch]      master -> master

Be sure to find and learn your Heroku application name in the output.

This process will probably take about twice as long as your 'bundle install' and then will return you to your console prompt. If it takes longer than that, talk to a TA.

Type this in the terminal:
heroku run rake db:migrate
Expected result:
Migrating to CreateDrinks (20120428044153)
==  CreateDrinks: migrating ===================================================
-- create_table(:drinks)
   -> 0.0084s
==  CreateDrinks: migrated (0.0085s) ==========================================

The long number after CreateDrinks is a timestamp. Yours will be different!

Step 7.6: Visit your new application

In the browser, go to your application's URL. You'll need your Heroku application name.

To find your Heroku application name

Type this in the terminal:
heroku info

To quickly open your heroku application in a browser

Type this in the terminal:
heroku open

The URL for your app is application-name.heroku.com -- so with the example output in the previous step, it would be floating-winter-18.heroku.com. Verify you see the welcome page. Leave this browser window open.

Create and save a new drink to verify you can write to the database on Heroku.

Next Step:

Go on to Get A Sticker

Back to Create A Heroku Account

If you find something that could be improved, please make a pull request or drop us a note via GitHub Issues (no technical knowledge required).

Source: https://github.com/RailsBridge-CapeTown