Deploying Ruby apps

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Learn how to deploy a Ruby app to Cloud Foundry. If you experience a problem following the steps, check the Troubleshooting Cloud Foundry topic, or refer to the Troubleshooting application deployment and health topic.

If you want to go through this tutorial using the sample app, run git clone https://github.com/cloudfoundry-samples/pong_matcher_ruby.git to clone the pongmatcherruby app from GitHub, and follow the instructions in the Sample app step sections.

Ensure that your Ruby app runs locally before continuing with this procedure.

Deploy a Ruby app

You can deploy a Ruby application to Cloud Foundry, and use the output from a sample app to show specific steps of the deployment process.

Prerequisites

Step 1: Create and bind a service instance for a Ruby app

Use the cf CLI to configure a Redis Cloud managed service instance for an app.

Cloud Foundry supports the following types of service instances:

  • Managed services integrate with Cloud Foundry through service brokers that offer services and plans and manage the service calls between Cloud Foundry and a service provider.
  • User-provided service instances enable you to connect your application to pre-provisioned external service instances.

For more information about creating and using service instances, refer to the Services Overview topic.

Creating a service instance

To create a service instance:

  1. View managed and user provided services and plans that are available to you by running:

    cf marketplace
    

    The example shows three of the available managed database-as-a-service providers and the plans that they offer: cleardb MySQL and postgresql-10-odb PostgreSQL as a Service.

    $  cf marketplace
    Getting services from marketplace in org Cloud-Apps / space development as clouduser@example.com...
    OK
    
    service             plans                                     description
    ...
    cleardb             spark, boost, amp, shock                  Highly available MySQL for your Apps
    ...
    postgresql-10-odb   standalone, standalone-replica, general   PostgreSQL as a Service
    ...
    
  2. Create a service instance for your app.

    cf create-service SERVICE PLAN SERVICE-INSTANCE
    

    Choose a SERVICE and PLAN from the list, and provide a unique name for the SERVICE-INSTANCE.

    Run cf create-service rediscloud 30mb redis. This creates a service instance named redis that uses the rediscloud service and the 30mb plan, as the example below shows.

    $ cf create-service rediscloud 30mb redis
    Creating service redis in org Cloud-Apps / space development as clouduser@example.com....
    OK
    

(Optional) Bind a service instance

When you bind an app to a service instance, Cloud Foundry writes information about the service instance to the VCAP_SERVICES app environment variable. The app can use this information to integrate with the service instance.

Most services support bindable service instances. Refer to your service provider’s documentation to confirm if they support this functionality.

You can bind a service to an application by running:

cf bind-service APPLICATION SERVICE-INSTANCE

Alternately, you can configure the deployment manifest file by adding a services block to the applications block and specifying the service instance. For more information and an example on service binding using a manifest, see the Sample app step.

You can skip this step. The manifest.yml for the sample app contains a services sub-block in the applications block, as the example below shows. This binds the redis service instance that you created in the previous step.

services:
      - redis

(Optional) Step 2: Configure deployment options

Configure the deployment manifest file

You can specify app deployment options in a manifest that the cf push command uses. For more information about application manifests and supported attributes, refer to the Deploying with Application Manifests topic.

Configure a production server

Cloud Foundry uses the default standard Ruby web server library, WEBrick, for Ruby and RoR apps. However, Cloud Foundry can support a more robust production web server, such as Phusion Passenger, Puma, Thin, or Unicorn. If your app requires a more robust web server, refer to the Configuring a Production Server topic for help configuring a server other than WEBrick.

You can skip this step. The manifest.yml file for pongmatcherruby does not require any additional configuration to deploy the app.

Step 3: Log in and target the API endpoint

Enter your login credentials, and select a space and org.

cf login -a API-ENDPOINT

The API endpoint is the URL of the Cloud Controller in your App Cloud instance.

You must do this step to run the sample app.

Step 4: Deploy an app

You must use the cf CLI to deploy apps.

Deploy your application by running the following command from the root directory of your application:

cf push APP-NAME

This command creates a URL route to your application in the form HOST.DOMAIN, where HOST is your APP-NAME and DOMAIN is specified by your administrator. Your DOMAIN isscapp.io.

For example, cf push my-app creates the URL my-app.scapp.io.

The URL for your app must be unique from other apps that Cloud Foundry hosts or the push fails. Use the following options to help create a unique URL:

  • -n to assign a different HOST name for the app.
  • --random-route to create a URL that includes the app name and random words.
  • cf help push to view other options for this command.

If you want to view log activity while the app deploys, launch a new terminal window and run cf logs APP-NAME.

Once your app deploys, browse to your app URL. Search for the urls field in the App started block in the output of the cf push command. Use the URL to access your app online.

Run cf push pongmatcherruby -n HOSTNAME.

Example: cf push pong
matcherruby -n pongmatch-ex12

The following example shows the terminal output of deploying the pong
matcher_ruby app. The ncf push command uses the instructions in the manifest file to create the app, create and bind the route, and upload the app. It then binds the app to the redis service and follows the instructions in the manifest to start one instance of the app with 256M. After the app starts, the output displays the health and status of the app.

These examples work for cf CLI v6. The -n flag is not supported for cf CLI v7/v8. Hostname must be set using the routes property in the manifest.

The pongmatcherruby app does not include a web interface. To interact with the pongmatcherruby app, see the interaction instructions on GitHub: https://github.com/cloudfoundry-samples/pong_matcher_ruby.

$ cf push pong_matcher_ruby -n pongmatch-ex12
Using manifest file /Users/clouduser/workspace/pong_matcher_ruby/manifest.yml

Creating app pong_matcher_ruby in org Cloud-Apps / space development as clouduser@example.com...
OK

Creating route pongmatch-ex12.scapp.io
        Binding pongmatch-ex12.scapp.io to pong_matcher_ruby...
OK

Uploading pong_matcher_ruby...
Uploading app files from: /Users/clouduser/workspace/pong_matcher_ruby
Uploading 8.8K, 12 files
OK
Binding service redis to app pong_matcher_ruby in org Cloud-Apps / space development as clouduser@example.com...
OK

Starting app pong_matcher_ruby in org Cloud-Apps / space development as clouduser@example.com...
OK
...

0 of 1 instances running, 1 starting
1 of 1 instances running

App started

Showing health and status for app pong_matcher_ruby in org Cloud-Apps / space development as clouduser@example.com...
OK

requested state: started
instances: 1/1
usage: 256M x 1 instances
urls: pongmatch-ex12.cfapps.io

     state     since                    cpu    memory          disk
#0   running   2014-12-09 10:04:40 AM   0.0%   35.2M of 256M   45.8M of 1G

Step 5: Test a deployed app

You’ve deployed an app to Cloud Foundry!

Use the cf CLI to review information and administer your app and your account. For example, you could edit the manifest.yml to increase the number of app instances from 1 to 3, and redeploy the app with a new app name and host name.

See the Manage Your Application with the cf CLI section for more information.

Manage your application with the cf CLI

Run cf help to view a complete list of commands, grouped by task categories, and run cf help COMMAND for detailed information about a specific command. For more information about using the cf CLI, refer to the Cloud Foundry Command Line Interface (cf CLI) topics, especially the Getting Started with the cf CLI topic.

You cannot perform certain tasks in the CLI because these are commands that only an administrator can run. If you are not an administrator, the following message displays for these types of commands:

error code: 10003, message: You are not authorized to perform the requested action

Troubleshooting

If your application fails to start, verify that the application starts in your local environment. Refer to the Troubleshooting Application Deployment and Health topic to learn more about troubleshooting.

App deploy fails

Even when deploying an app fails, the app might exist on Cloud Foundry. Run cf apps to review the apps in the targeted org and space. You might be able to correct the issue using the CLI, or you might have to delete the app and redeploy it.

Common reasons deploying an app fails include:

  • You did not successfully create and bind a needed service instance to the app, such as a PostgreSQL service instance. Refer to Step 2: Create and Bind a Service Instance for a Ruby Application.
  • You did not successfully create a unique URL for the app. Refer to the troubleshooting tip App Requires Unique URL.

App requires unique URL

Cloud Foundry requires that each app that you deploy has a unique URL. Otherwise, the new app URL collides with an existing app URL and Cloud Foundry cannot successfully deploy the app. You can fix this issue by running cf push with the --random-route flag to create a unique URL. Using --random-route to create a URL that includes the app name and random words might create a long URL, depending on the number of words that the app name includes.

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