Deploying Web Applications in the Cloud

In this chapter we will learn about deploying Ring Web Applications in the Cloud using Heroku

Introduction

We created a new project and tutorial to explain how to deploy Ring web applications in the Cloud using Heroku

Project : https://github.com/ring-lang/RingWebAppOnHeroku

Heroku Website : https://www.heroku.com/

Usage

To use this project and deploy it on Heroku

1. Create Heroku account

2. Open your Heroku account and create new application

Example : testring

Note (You have to select a unique name for your application)

3. Open the command prompt, Create new folder : MyApp

md MyApp

4. Open the application folder

cd MyApp

5. Clone this project using Git (Don’t forget the dot in the end to clone in the current directory)

git clone https://github.com/ring-lang/RingWebAppOnHeroku .

6. Login to Heroku (Enter your Email and Password)

heroku login

7. Add heroku (remote) to your Git project

change testring to your application name

heroku git:remote -a testring

8. Set the buildpacks (So Heroku can know how to support your project)

heroku buildpacks:add --index 1 https://github.com/ring-lang/heroku-buildpack-apt
heroku buildpacks:add --index 2 https://github.com/ring-lang/heroku-buildpack-ring

9. Now build your project and deploy it

git push heroku master

10. Test your project (In the browser)

heroku open

Ring source code files and permissions

To be able to run your new Ring scripts, Set the permission of the file to be executable using Git

For example, if you created a file : myscript.ring

git update-index --chmod=+x myscript.ring
git commit -m "Update file permission"

If you are using TortoiseGit, From windows explorer, select the file

Right click —> Properties —> Git —> Executable (+x)

Then commit and deploy!

Hello World program

file : ringapp/helloworld.ring

#!/app/runring.sh -cgi

see "content-type: text/html" +nl+nl
see "Hello, World!" + nl

file : ringapp/helloworld2.ring

#!/app/runring.sh -cgi
load "weblib.ring"
import System.Web
new page {
        text("Hello, World!")
}

Application Database

When you deploy the application, Everything will works directly!

No change is required, but in practice, You will need to update the next files to use your database

There are two scripts to interact with the database (We are using PostgreSQL in the cloud)

You will need to update the connection string in these files if you will use another database

• file: ringapp/database/newdb.ring (We run it using the browser for one time to create the tables)

• file: ringapp/datalib.ring (Class: Database)

In your practical projects, You can write better code (To be able to change the database)

Also you can create configuration file (To write the connection string in one place)

Database service : https://www.heroku.com/postgres

Deploying after updates

Just use Git and commit then push to heroku

file: build.bat contains the next commands for quick tests

git add .
git commit -m "Update RingWebAppOnHeroku"
git push heroku master
heroku open

Local Tests

Local tests using Ring Notepad on Windows (Using local Apache Web Server)

Replace the first line in the file : ringapp/index.ring with

#!ring -cgi

Then run it from Ring Notepad (Ctrl+F6)