Install New Relic Ruby agent in GAE flexible environment

With New Relic APM's Ruby agent, you can monitor applications that reside in the Google App Engine (GAE) flexible environment. Adding New Relic to your GAE flex app gives you insight into the health and performance of your app and extends GAE with metrics you can view in New Relic APM, Browser, and Insights.

This document explains how to add New Relic to your GAE flex app using either of these methods:

The custom runtime method includes an example of deploying a Sinatra app. If you need specific libraries or headers, New Relic recommends using the custom runtime method.

Deploy using GAE's native support

When using Google App Engine "native mode" installation, you provide your app code and an app.yaml file. Google App Engine then deploys to a standard prebuilt Docker image.

To deploy with native support for Sinatra or Rails:

  1. Follow New Relic's standard procedures to install the gem, including your license key.
  2. Install the Ruby agent configuration file.

Once the gem and configuration file have been installed, the Ruby agent can automatically monitor applications that reside in the GAE flexible environment. Wait until the deployment completes, then view your GAE flex app data in the New Relic APM Overview page.

Build a custom runtime using Docker

If your Ruby app needs specific libraries or headers, New Relic recommends using the custom runtime method. In addition, New Relic recommends that you allow Google App Engine to handle health checks.

See Google's documentation for building custom runtimes. This example describes how to add New Relic to your GAE flex app by building a custom runtime for Docker. The example uses a Sinatra app for Ruby.

For more information about deploying and configuring your Ruby app in the GAE flexible environment, see:

1. Set up the GAE project and install dependencies
  1. Follow standard procedures to install New Relic's Ruby agent, including your license key.
  2. Follow Google App Engine procedures for Ruby to create a new Google Cloud Platform project, create an App Engine application, and complete other prerequisites for the Google Cloud SDK.

The Google Cloud SDK provides the gcloud command line tool to manage and deploy GAE apps.

2. Configure your app.yaml

The app.yaml configuration file is required for a GAE flexible environment app with a custom runtime. At a minimum, make sure it contains:

env: flex
runtime: custom
entrypoint: bundle exec ruby app.rb
3. Configure a Dockerfile

The Dockerfile defines the Docker image to be built and is required for a GAE flexible environment app. To create the recommended base image for apps monitored by the New Relic Ruby agent:

FROM gcr.io/google-appengine/ruby:latest
4. Build a Docker image

Be sure to include the period at the end of the code, to indicate the current directory contains the build files.

docker build -f Dockerfile -t custom_ruby_app_container:latest .

After running this command, verify that you have a Docker image named custom_ruby_app_container and tagged latest.

5. Deploy Docker image to initialized GAE flexible environment
  1. To deploy your Docker image to your initialized GAE flexible environment, run the following command:

    gcloud app deploy
  2. Wait until the deployment completes.
  3. To open the app in the browser, run the following command:

    gcloud app browse
  4. To view your GAE flex app data in New Relic, go to the New Relic APM Overview page.

Recommendation: Handle health checks

Google App Engine sends periodic health check requests to confirm that an instance has been successfully deployed, and to check that a running instance maintains a healthy status. A health check is an HTTP request to the URL /_ah/health.

If you create a custom runtime, your app must be able to handle a large number of health check requests. Otherwise, your app data may not display correctly in New Relic APM.

New Relic recommends that you allow health checks for Ruby apps so that Google can check that your service is up and balanced properly. However, if excessive health checks cause congested transaction traces, you can set the Ruby agent to ignore the health check requests.

  • To handle health checks, add a route for _ah/health in your app.
  • To ignore health check requests, set the rules.ignore_url_regexes config setting in the application’s Ruby agent config to include '_ah/health'.

Get New Relic agent troubleshooting logs from GAE

Use these resources to troubleshoot your GAE flex environment app:

For more help

Recommendations for learning more: