Test Driving Cloud Run

So today, I decided to give Google’s new serverless compute offering Cloud Run a spin.

What’s Cloud Run?

Cloud Run is a brand new service that Google announced at NEXT 2019.

In short, Cloud Run lets you run stateless HTTP containers on GCP in an effortless, production-ready way. The Cloud Run service will handle autoscaling, high-availability and more for you and you are only charged for the actual execution time of the running container instances.

You can run a fully serverless version on Google’s clusters or enjoy the same experience on your own GKE clusters (yes, in your private VPC) with Cloud Run on GKE. Cloud Run itself is built on knative so it is almost safe to assume that the fully serverless Cloud Run is just Cloud Run on GKE, but running on Google’s own shared GKE clusters (probably separated by k8s namespaces). But I am blindly guessing here, so don’t bet on my assumptions :)

The service is currently in public beta. At the moment, the fully serverless version is only available in us-central1, but that is going to change when the service leaves its beta phase.

Looking at other cloud providers, Cloud Run seems similar to Azure Container Instances. Now, ACI doesn’t scale very well and it is not designed for production workloads, but when we look at the use case in which a developer wants to quickly bring up a containerized web service, ACI seems very similar to Cloud Run. The closest equivalent of Cloud Run on AWS is Fargate. It also provides a serverless container execution runtime, however, Fargate comes with a lot more configuration, flexibility, and power. Cloud Run seems to bring the best of both Fargate and ACI to the table. ACI seemed only like a toy for developers, who quickly want to show or test something they build. Fargate can be a bit scary for engineers, who are not exposed to it regularly. Cloud Run makes a few assumptions about your workload, welds these assumptions into its runtime contract and provides you with a very powerful tool for the majority of use cases on the web.

Is it really that simple to use?

Yes, it is. It is a wonderful joy to use. I quickly stiched together the simplest ruby web service that stills adheres to Cloud Run runtime contract and that I could think of. It is available here.

You’ll need to have the beta extensions for gcloud installed and the Cloud Run service needs to be enabled for your GCP project.

Of course, you need to have a container. Cloud Run’s runtime contract tells you, that the web service of your container needs to bind 0.0.0.0 and listen to the port that is dictated by Cloud Run and given to your container as the environment variable $PORT.

Here is a simple ruby source file, which defines a HTTP server using the sinatra framework.

require 'sinatra'

set :bind, '0.0.0.0'
set :port, ENV["PORT"]

get '/' do
  "I am running on Cloud Run!"
end

Now we need to containerize the web service and push the image to Google Container Registry. You can run the docker build locally (and test your web-service) or you can run the build on Google Cloud Build.

Finally, it’s deployment time with Cloud Run and it is crazy simple to use.

gcloud beta run deploy my-service --allow-unauthenticated --image gcr.io/my-project/my-image

Lastly, you can find the HTTPS-secured endpoint for your new service by querying the Cloud Run service like so:

yq r <(gcloud beta run services describe my-service) status.address.hostname

There you go. You have a load-balanced, highly available, extremely elastic web service secured with TLS certificates deployed to a production-ready environment. And you only pay when it is actually in use.

Conclusion

I can’t wait to build cool stuff on Cloud Run. Especially when I think about the interaction with Cloud Tasks, I can see loads of decoupled asynchronous event-driven architectures come to life.

Cloud Run makes it so incredibly easy to deploy the single most-seen use case for cloud-native application deployments on the modern web. This significantly lowers the barriers for developers to quickly release new services and build awesome solutions in a matter of minutes. Well done, Google!

Written by Daniel Stamer on 22 April 2019
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