Getting started with Ruby on IBM Cloud

This guide will take you through the steps to get started with a simple Ruby application and help you:

• set up a development environment
• download sample code
• run locally
• run on IBM Cloud, and
• add a IBM Cloud database service to the sample

Prerequisites

You'll need the following:

• IBM Cloud account
• Cloud Foundry CLI
• Git
• Ruby
• rbenv

1. Clone the sample app

Now you're ready to start working with the app. Clone the repo and change the directory to where the sample app is located.

git clone https://github.com/IBM-Cloud/get-started-ruby
cd get-started-ruby

3. Run the app locally

Dependencies:

rbenv install 2.3.0
rbenv local 2.3.0
gem install bundler
bundle install

Run the app:

rails server

View your app at: http://localhost:3000

3. Prepare the app for deployment

To deploy to IBM Cloud, it can be helpful to set up a manifest.yml file. One is provided for you with the sample. Take a moment to look at it.

The manifest.yml includes basic information about your app, such as the name, how much memory to allocate for each instance and the route. In this manifest.yml random-route: true generates a random route for your app to prevent your route from colliding with others. You can replace random-route: true with host: myChosenHostName, supplying a host name of your choice. Learn more...

applications:
- name: GetStartedRuby
  random-route: true
  memory: 128M

4. Deploy the app

You can use the Cloud Foundry CLI to deploy apps.

Choose your API endpoint

cf api <API-endpoint>

Replace the API-endpoint in the command with an API endpoint from the following list.

URL	Region
https://api.ng.bluemix.net	US South
https://api.eu-de.bluemix.net	Germany
https://api.eu-gb.bluemix.net	United Kingdom
https://api.au-syd.bluemix.net	Sydney

Login to your IBM Cloud account

cf login

From within the get-started-node directory push your app to IBM Cloud

cf push

This can take a minute. If there is an error in the deployment process you can use the command cf logs <Your-App-Name> --recent to troubleshoot.

When deployment completes you should see a message indicating that your app is running. View your app at the URL listed in the output of the push command. You can also issue the

cf apps

command to view your apps status and see the URL.

5. Add a database

Next, we'll add a NoSQL database to this application and set up the application so that it can run locally and on IBM Cloud.

1. Log in to IBM Cloud in your Browser. Browse to the Dashboard. Select your application by clicking on its name in the Name column.
2. Click on Connections then Connect new.
3. In the Data & Analytics section, select Cloudant NoSQL DB and Create the service.
4. Select Restage when prompted. IBM Cloud will restart your application and provide the database credentials to your application using the VCAP_SERVICES environment variable. This environment variable is only available to the application when it is running on IBM Cloud.

Environment variables enable you to separate deployment settings from your source code. For example, instead of hardcoding a database password, you can store this in an environment variable which you reference in your source code. Learn more...

6. Use the database

We're now going to update your local code to point to this database. We'll create a json file that will store the credentials for the services the application will use. This file will get used ONLY when the application is running locally. When running in IBM Cloud, the credentials will be read from the VCAP_SERVICES environment variable.

1. Create a file called .env in the get-started-ruby directory with the following content:

CLOUDANT_URL=

2. Back in the IBM Cloud UI, select your App -> Connections -> Cloudant -> View Credentials

3. Copy and paste just the url from the credentials to the CLOUDANT_URL field of the .env file and save the changes. The result will be something like:

CLOUDANT_URL=https://123456789 ... bluemix.cloudant.com

4. Run your application locally.

rails server

View your app at: http://localhost:3000. Any names you enter into the app will now get added to the database.

Your local app and the IBM Cloud app are sharing the database. View your IBM Cloud app at the URL listed in the output of the push command from above. Names you add from either app should appear in both when you refresh the browsers.