Ruby Rack-based Apps on App42 PaaS

Rack aims to provide a minimal API, to develop web applications in Ruby, for connecting web servers supporting Ruby (like WEBrick, Mongrel,Passenger etc.) and Ruby web frameworks (like Rails, Sinatra, Padrino etc.).

To run a Rack-based app, Application must have include a Gemfile and rackup file named in the app’s root directory. The file allows you to easily deal with HTTP requests. Below are the steps you have to follow:


Kontena – Kontena is a lightweight container that will run your apps and services in an isolated and secured manner. You can specify the power of the Kontena while setting up infra or creating services. One Kontena power specifies to 256 MB Memory and 128 MHz CPU.

Service – Services in the App42 PaaS are add-on components which are needed in an App. App42 PaaS supports multiple services like SQL databases, NoSQL databases and more.


To get going with App42 PaaS, below are few prerequisites that will allow you to use AppHQ – App42 PaaS Management Console as well as Command Line Client.

Setup infrastructure for Ruby Rack-based application

To deploy your Ruby application on App42 PaaS, You first need to setup an environment by providing certain inputs which will run your app. Below is the screenshot of setting up the required environment for your app using Command Line Client. You can also perform the same using AppHQ – App42 PaaS Management Console.

$app42 setupInfra
Application Name: rubydemo

Checking App Name Availability... OK

1: Shared
Select Instance Type [Shared]: 

1: Amazon (Oregon)
Select IaaS Provider [Amazon (Oregon)]: 

1: Ruby 2.0.0
2: Java 6
3: Java 7
4: PHP 5.3
5: PHP 5.5
Select Runtime [Ruby 2.0.0]: 

1: Ruby on Rack 
2: Rails 4.0
3: Sinatra 1.4
Select Framework [Ruby on Rack ]: 

1: Nginx 1.4.1
Select Web Server [Nginx 1.4.1]: 

Specify Kontena Power: 5
Setting up the infrastructure... OK
Operation is in progress, Please wait.../
Setup Infra completed successfully.

Default application has been deployed. You can visit '' to see the default application.
Create Your Application

You may be starting from an existing app. if not, you can also use our Sample Apps and extend it to suit your needs. Here is the link to Ruby Sample App .

Deploy a Ruby application

You can deploy the application on App42 PaaS platform using two ways. One, you can create a binary (including all dependencies) on your local development environment. Other, you can deploy your application by providing the Git repository URL of your app.

NOTE: In case of deploying from source, Either the provided Git repository must be public or if you want to deploy from private repository, you need to provide the pull permission to App42PaaS Github user.

Deploy Binary

$ app42 deploy
Enter App Name: rubydemo
1: Binary
2: Source
Choose Upload Type [Binary]: 1

Would you like to deploy from the current directory? [Yn]: n
Binary Deployment Path: /home/ubuntu/workspace/App42PasS/sample_app/App42PaaS-Ruby-Sample
Please be patient... This process may take a while to complete.
Deploying Application... OK

Operation is in progress, Please wait...|
App deployed successfully.

Deploy Source

$ app42 deploy
Enter App Name: rubydemo
1: Binary
2: Source
Choose Upload Type [Binary]: 2

Enter Git URL?:
Deploying Application... OK

Operation is in progress, Please wait...|
App deployed successfully.

Get application details

You can see the details of your setup environment either from AppHQ – App42 PaaS Management Console or Command Line Client using app42 appInfo.

$ app42 appInfo --app rubydemo
|                                           === rubydemo Info ===                                          |
| App Url                             | App Status | Iaas Provider    | Name     | Runtime  | Instance Count | Memory|
| | RUNNING    | Amazon (Oregon)  | rubydemo |Ruby 2.0.0| 1             | 512 MB |
Visit Your Application

You’ve deployed your application to App42 PaaS. Now you can open your application in your favorite browser.