Announcing support for gRPC

Today we're excited to announce beta support for proxying gRPC, a next-generation protocol that allows you to build APIs at scale. With gRPC on Cloudflare, you get access to the security, reliability and performance features that you're used to having at your fingertips for traditional APIs. Sign up for the beta today in the Network tab of the Cloudflare dashboard.

gRPC has proven itself to be a popular new protocol for building APIs at scale: it’s more efficient and built to offer superior bi-directional streaming capabilities. However, because gRPC uses newer technology, like HTTP/2, under the covers, existing security and performance tools did not support gRPC traffic out of the box. This meant that customers adopting gRPC to power their APIs had to pick between modernity on one hand, and things like security, performance, and reliability on the other. Because supporting modern protocols and making sure people can operate them safely and performantly is in our DNA, we set out to fix this.

When you put your gRPC APIs on Cloudflare, you immediately gain the benefits that come with Cloudflare. Apprehensive of exposing your APIs to bad actors? Add security features such as WAF and Bot Management. Need more performance? Turn on Argo Smart Routing to decrease time to first byte. Or increase reliability by adding a Load Balancer.

And naturally, gRPC plugs in to API Shield, allowing you to add more security by enforcing client authentication and schema validation at the edge.

Protocols like JSON-REST have been the bread and butter of Internet facing APIs for several years. They're great in that they operate over HTTP, their payloads are human readable, and a large body of tooling exists to quickly set up an API for another machine to talk to. However, the same things that make these protocols popular are also weaknesses; JSON, as an example, is inefficient to store and transmit, and expensive for computers to parse.

In 2015, Google introduced gRPC, a protocol designed to be fast and efficient, relying on binary protocol buffers to serialize messages before they are transferred over the wire. This prevents (normal) humans from reading them but results in much higher processing efficiency. gRPC has become increasingly popular in the era of microservices because it neatly addresses the shortfalls laid out above.

JSON

Protocol Buffers

{ “foo”: “bar” }

0b111001001100001011000100000001100001010

gRPC relies on HTTP/2 as a transport mechanism. This poses a problem for customers trying to deploy common security technologies like web application firewalls, as most reverse proxy solutions (including Cloudflare’s HTTP stack, until today) downgrade HTTP requests down to HTTP/1.1 before sending them off to an origin.

Beyond microservices in a datacenter, the original use case for gRPC, adoption has grown in many other contexts. Many popular mobile apps have millions of users, that all rely on messages being sent back and forth between mobile phones and servers. We've seen many customers wire up API connectivity for their mobile apps by using the same gRPC API endpoints they already have inside their data centers for communication with clients in the outside world.

While this solves the efficiency issues with running services at scale, it exposes critical parts of these customers' infrastructure to the Internet, introducing security and reliability issues. Today we are introducing support for gRPC at Cloudflare, to secure and improve the experience of running gRPC APIs on the Internet.

The engineering work our team had to do to add gRPC support is composed of a few pieces:

1. Changes to the early stages of our request processing pipeline to identify gRPC traffic coming down the wire.

2. Additional functionality in our WAF to “understand” gRPC traffic, ensuring gRPC connections are handled correctly within the WAF, including inspecting all components of the initial gRPC connection request.

3. Adding support to establish HTTP/2 connections to customer origins for gRPC traffic, allowing gRPC to be proxied through our edge. HTTP/2 to origin support is currently limited to gRPC traffic, though we expect to expand the scope of traffic proxied back to origin over HTTP/2 soon.

What does this mean for you, a Cloudflare customer interested in using our tools to secure and accelerate your API? Because of the hard work we’ve done, enabling support for gRPC is a click of a button in the Cloudflare dashboard.

Why does Cloudflare supporting gRPC matter? To dig in on one use case, let’s look at mobile apps. Apps need quick, efficient ways of interacting with servers to get the information needed to show on your phone. There is no browser, so they rely on APIs to get the information. An API stands for application programming interface and is a standardized way for machines (say, your phone and a server) to talk to each other.

Let's say we're a mobile app developer with thousands, or even millions of users. With this many users, using a modern protocol, gRPC, allows us to run less compute infrastructure than would be necessary with older, less efficient protocols like JSON-REST. But exposing these endpoints, naked, on the Internet is really scary. Up until now there were very few, if any, options for protecting gRPC endpoints against application layer attacks with a WAF and guarding against volumetric attacks with DDoS mitigation tools. That changes today, with Cloudflare adding gRPC to it’s set of supported protocols.  

With gRPC on Cloudflare, you get the benefits of our security, reliability and performance products:

• WAF for inspection of incoming gRPC requests. Use managed rules or craft your own.

• Load Balancing to increase reliability: configure multiple gRPC backends to handle the load, let Cloudflare distribute the load across them. Backend selection can be done in round-robin fashion, based on health checks or load.

• Argo Smart Routing to increase performance by transporting your gRPC messages faster than the Internet would be able to route them. Messages are routed around congestion on the Internet, resulting in an average reduction of time to first byte by 30%.

And of course, all of this works with API Shield, an easy way to add mTLS authentication to any API endpoint.

To enable gRPC support, head to the Cloudflare dashboard and go to the Network tab. From there you can sign up for the beta.

We have limited seats available at launch, but will open up more broadly over the next few weeks. After signing up and toggling gRPC support, you’ll have to enable Cloudflare proxying on your domain on the DNS tab to activate Cloudflare for your gRPC API.

We’re excited to bring gRPC support to the masses, allowing you to add the security, reliability and performance benefits that you’re used to getting with Cloudflare. Enabling is just a click away. Take it for a spin and let us know what you think!