Get started developing Ruby on Rails apps that run on App Engine flexible environment. The apps you create run on the same infrastructure that powers all of Google's products, so you can be confident that they can scale to serve all of your users, whether there are a few or millions of them.
This tutorial assumes you are familiar with Rails web development. It walks you through deploying a new Rails app.
This tutorial requires Ruby 2.3.3 or newer.
Before you begin
- Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
In the Google Cloud Console, on the project selector page, select or create a Google Cloud project.
Make sure that billing is enabled for your Cloud project. Learn how to confirm that billing is enabled for your project.
- Install and initialize the Cloud SDK.
Set up your local environment for Rails
Before you begin, take the following steps:
Alternatively, you can use Cloud Shell, which comes with Ruby, Rails, and the Cloud SDK already installed.
For additional information on installing Rails and its dependencies, see the official Getting started with Rails guide.
After you complete the prerequisites, you can create and deploy a Rails app. The following sections guide you through configuring, running, and deploying an app.
Create a new app
Scaffold a new Rails sample app.
rails new appengine_example
Go to the directory that contains the sample code.
Run the app locally
To run the new Rails app on your local computer:
Install dependencies by using Bundler.
Start a local web server.
bundle exec rails server
In your browser, go to http://localhost:3000/.
You see the "Yay! You’re on Rails!" message from the sample app displayed on the page.
Add a simple page
Now add a Welcome page to the generated Rails app.
To generate the scaffolding for a new page, create a new Rails controller named
bundle exec rails generate controller Welcome index
Open the file
app/views/welcome/index.html.erbto see the following boilerplate HTML.
<h1>Welcome#index</h1> <p>Find me in app/views/welcome/index.html.erb</p>
Modify the file however you like. For example, you can use the following content:
<h1>Welcome</h1> <p>This is a home page for a new Rails App on Google Cloud Platform!</p>
indexcontroller action as the root action for Rails. Then, whenever a user visits the Rails app, they see your welcome page.
Open the file
config/routes.rbto see the following generated content.
Rails.application.routes.draw do get 'welcome/index' # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html end
To modify this file, add
Rails.application.routes.draw do get 'welcome/index' # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html root 'welcome#index' end
Save the file and close it. Test the Rails app as you did before.
Deploy the app to App Engine flexible environment
App Engine flexible environment uses a file called
to describe an app's deployment configuration. If this file isn't present, the
gcloud command line tool tries to guess the deployment configuration. However,
it is a good idea to provide this file because Rails requires a secret key in a
To configure the sample app for deployment to App Engine, create a new
app.yaml at the root of your sample app directory and add the
entrypoint: bundle exec rackup --port $PORT env: flex runtime: ruby
Configure the Rails secret key
When you deploy a Rails app in the production environment, set the environment
SECRET_KEY_BASE to a secret key that is used to protect
user session data. This environment variable is read in the
Generate a new secret key.
bundle exec rails secret
Copy the generated secret key. You use the secret key in the next step.
Open the file
app.yamlthat you created earlier, and add an
env_variablessets environment variables in the
productionenvironment in App Engine flexible environment. Your
app.yamlshould look like the example below, with
[SECRET_KEY]replaced with your copied secret key.
entrypoint: bundle exec rackup --port $PORT env: flex runtime: ruby env_variables: SECRET_KEY_BASE: [SECRET_KEY]
Set up an App Engine flexible environment app
If this is the first time you are deploying an app, you need to create an App Engine flexible environment app to help you select the region in which to run the Rails app. You can read more about regions and zones.
Create an App Engine app.
gcloud app create
Select a region that supports App Engine flexible environment for Ruby apps.
Deploy to App Engine flexible environment
Before you deploy, precompile your Rails assets.
RAILS_ENV=production bundle exec rails assets:precompile
After the assets finish compiling, deploy the sample.
gcloud app deploy
Wait for the message that notifies you that the update has completed. This can take several minutes.
Access the deployed Rails app
To retrieve your project ID, run
In your browser, enter the following URL:
Replace the following:
PROJECT_ID: Your Google Cloud project ID
REGION_ID: A code that App Engine assigns to your app
The following content is displayed.
This time, your request is served by the Rails app running in App Engine flexible environment.
This command deploys the app as described in
app.yaml and sets the newly
deployed version as the default version, causing it to serve all new traffic.
As the app deploys, you might see several repeated messages while the
platform checks whether the app is serving. This is normal. Wait for the
message that notifies you that the update of the app is complete.
If you update your app, you can deploy the updated version by entering the same command you used to deploy the app the first time. The new deployment creates a new version of your app and promotes it to the default version. The older versions of your app remain, as do their associated VM instances. Be aware that all of these app versions and VM instances are billable resources.
Read App Engine logs
Now that you have deployed your Rails app, you may want to read the logs. You
can read the app logs by using the
located in the Cloud Console, or by using
gcloud app logs read.
You can learn more about
reading logs by using the Cloud SDK.
Clean up resources
After you've finished the Running Rails 5 in the App Engine tutorial, you can clean up the resources that you created on Google Cloud so they won't take up quota and you won't be billed for them in the future. The following sections describe how to delete or turn off these resources.
The easiest way to eliminate billing is to delete the project that you created for the tutorial.
To delete the project:
- In the Cloud Console, go to the Manage resources page.
- In the project list, select the project that you want to delete, and then click Delete.
- In the dialog, type the project ID, and then click Shut down to delete the project.
Delete an App Engine version
To delete an app version:
- In the Cloud Console, go to the Versions page for App Engine.
- Select the checkbox for the non-default app version that you want to delete.
- To delete the app version, click Delete.
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