Deploying Ruby on Rails apps

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You can use this information to deploy a Ruby on Rails app to Cloud Foundry.

Prerequisites

In order to deploy a sample Ruby on Rails app, you must have the following:

• Cloud Foundry deployment
• Cloud Foundry Command Line Interface
• Cloud Foundry username and password with Space Developer permissions. See your Org Manager if you require permissions.

Step 1: Clone the app

Run the following command to create a local copy of the cf-sample-app-rails:

git clone https://github.com/cloudfoundry-samples/cf-sample-app-rails.git

The newly created directory contains a manifest.yml file, which assists CF with deploying the app. See Deploying with Application Manifests for more information.

Step 2: Log in and target the API endpoint

1. Run the following terminal command to log in and target the API endpoint of your deployment. To find your API endpoint, visit the web console and open the settings sidebar of your space.

   cf login -a YOUR-API-ENDPOINT
   

2. Use your credentials to log in, and to select a Space and Org.

Step 3: Create a service instance

Run the following terminal command to create a PostgreSQL service instance for the sample app.

cf create-service postgresql-10-odb standalone rails-postgres

For example:

$ cf create-service postgresql-10-odb standalone rails-postgres
Creating service rails-postgres in org YOUR-ORG / space development as clouduser@example.com....
OK

The service instance is rails-postgres. It uses the postgresql-10-odb service and the standalone plan. For more information about the postgresql-10-odb service, see Crunchy PostgreSQL.

Step 4: Deploy the app

Make sure you are in the cf-sample-app-rails directory. Run the following command to deploy the app:

cf push cf-sample-app-rails

This command creates a URL route to your application in the form HOST.DOMAIN. In this example, HOST is cf-sample-app-rails. Administrators specify the DOMAIN.

For example, for the DOMAIN scapp.io, running the previous command creates the URL cf-sample-app-rails.scapp.io.

The following example shows the terminal output when deploying the cf-sample-app-rails. cf push uses the instructions in the manifest file to create the app, create and bind the route, and upload the app. It then follows the information in the manifest to start one instance of the app with 256M of RAM. After the app starts, the output displays the health and status of the app.

$ cf push cf-sample-app-rails
Using manifest file ~/workspace/cf-sample-app-rails/manifest.yml

Creating app cf-sample-app-rails in org my-rog / space dev as clouduser@example.com...
OK

Creating route cf-sample-app-rails.cfapps.io...
OK

Binding cf-sample-app-rails.cfapps.io to cf-sample-app-rails...
OK

Uploading cf-sample-app-rails...
Uploading app files from: ~/workspace/cf-sample-app-rails
Uploading 746.6K, 136 files
Done uploading
OK

Starting app cf-sample-app-rails in org my-org  / space dev as clouduser@example.com...
. . .
0 of 1 instances running, 1 starting
1 of 1 instances running

App started

OK

App cf-sample-app-rails was started using this command `bundle exec rails server -p $PORT`

Showing health and status for app cf-sample-app-rails in org my-org / space dev as clouduser@example.com...
OK

requested state: started
instances: 1/1
usage: 512M x 1 instances
urls: cf-sample-app-rails.cfapps.io
last uploaded: Wed 17 Jul 22:57:04 UTC 2024
stack: cflinuxfs3
buildpack: ruby

     state     since                  cpu    memory          disk           logging         cpu entitlement   details
#0   running   2024-07-17T22:57:22Z   0.3%   49.5M of 512M   130.2M of 1G   0B/s of 16K/s   2.4%

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

To avoid security exposure, verify that you migrate your apps and custom buildpacks to use the cflinuxfs4 stack based on Ubuntu 22.04 LTS (Jammy Jellyfish). The cflinuxfs3 stack is based on Ubuntu 18.04 (Bionic Beaver), which reaches end of standard support in April 2023.

Step 5: Bind the service instance

1. Run the following command to bind the service instance to the sample app. Once bound, environment variables are stored that allow the app to connect to the service after a cf push, cf restage, or cf restart command.

   $ cf bind-service cf-sample-app-rails rails-postgres
   Binding service rails-postgres to app cf-sample-app-rails in org my-org / space dev
   OK
   TIP: Use 'cf restage cf-sample-app-rails' to ensure your env variable changes take effect
   

2. Run the following command to restage the sample app.

   $ cf restage cf-sample-app-rails
   

3. Run the following command to verify the service instance is bound to the sample app.

   $ cf services
   Getting services in org my-org / space dev
   OK
   name             service             plan          bound apps            last operation
   rails-postgres   postgresql-10-odb   standalone    cf-sample-app-rails   create succeeded
   

Step 6: Verify the app

Verify that your app is running by browsing to the URL generated in the output of the previous step. In this example, go to cf-sample-app-rails.scapp.io and verify that the app is running.

For more information, see the Pushing an App topic.

Test a deployed app

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

Manage your app with the cf CLI

Run cf help to view a complete list of commands and run cf help COMMAND for detailed information about a specific command. For more information about using the cf CLI, refer to the cf CLI topics, especially the Getting Started with the cf CLI topic.

Troubleshooting

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